Bump github/codeql-action from 4 to 4.37.4

Bumps [github/codeql-action](https://github.com/github/codeql-action) from 4 to 4.37.4.
- [Release notes](https://github.com/github/codeql-action/releases)
- [Changelog](https://github.com/github/codeql-action/blob/main/CHANGELOG.md)
- [Commits](https://github.com/github/codeql-action/compare/v4...v4.37.4)

---
updated-dependencies:
- dependency-name: github/codeql-action
  dependency-version: 4.37.4
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/codeql-analysis.yml

@@ -33,12 +33,12 @@ jobs:
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v4
+      uses: github/codeql-action/init@v4.37.4
       with:
         languages: ${{ matrix.language }}
 
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v4
+      uses: github/codeql-action/autobuild@v4.37.4
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v4
+      uses: github/codeql-action/analyze@v4.37.4

.github/workflows/labeler.yml

@@ -12,6 +12,6 @@ jobs:
   label:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/labeler@v6
+      - uses: actions/labeler@v7
         with:
           configuration-path: .github/labeler.yml

.github/workflows/linux.yml

@@ -23,12 +23,12 @@ jobs:
         fetch-depth: 0
 
     - name: Set up Go
-      uses: actions/setup-go@v6
+      uses: actions/setup-go@v7
       with:
         go-version: "1.23"
 
     - name: Setup Ruby
-      uses: ruby/setup-ruby@9eb537ca036ebaed86729dcb9309076e4c5c3b74 # v1
+      uses: ruby/setup-ruby@95ef2b042f9d7a56d8268cba8559e2842e2ad01b # v1
       with:
         ruby-version: 3.4.6
 

.github/workflows/macos.yml

@@ -20,12 +20,12 @@ jobs:
         fetch-depth: 0
 
     - name: Set up Go
-      uses: actions/setup-go@v6
+      uses: actions/setup-go@v7
       with:
         go-version: "1.23"
 
     - name: Setup Ruby
-      uses: ruby/setup-ruby@9eb537ca036ebaed86729dcb9309076e4c5c3b74 # v1
+      uses: ruby/setup-ruby@95ef2b042f9d7a56d8268cba8559e2842e2ad01b # v1
       with:
         ruby-version: 3.0.0
 

.github/workflows/release.yml

@@ -23,7 +23,7 @@ jobs:
         with:
           fetch-depth: 0
 
-      - uses: actions/setup-go@v6
+      - uses: actions/setup-go@v7
         with:
           go-version: stable
 

CHANGELOG.md

@@ -1,8 +1,40 @@
 CHANGELOG
 =========
 
+0.74.2
+------
+- Performance optimizations for short queries
+    - Short queries scan the largest candidate sets, and the first keystroke scans the whole input
+    - Single-character queries are up to 2.4x faster
+    - Two-character queries are up to 1.4x faster
+- Faster sorting of search results, skipping redundant radix passes
+- `change-border-label` and `transform-border-label` now work on the native border of a tmux or Zellij floating pane
+- Fixed Kitty graphics sequences from a preview command being taken by tmux as pane title requests
+- Fixed an image at the top of the preview being torn by `--preview-window ~N`
+- Fixed nondeterministic match highlight positions
+- Fixed signal and resize handlers persisting after `Run()` returns when fzf is used as a library
+- fzf now detects terminal resize on Windows in `--height` mode (#4790) (@Cyrus580529)
+- fish: fixed history command being affected by user initialization scripts, and improved timestamp colors in CTRL-R (#4862) (@bitraid)
+- zsh: fixed CTRL-R not propagating the exit status of fzf when perl is available (#4871) (@LangLangBart, @Toliak)
+- zsh: fixed `chpwd` hook functions being called twice by ALT-C (#4879) (@LangLangBart, @lucc)
+
 0.74.1
 ------
+- The default separator on the info line is no longer shown when the input section is already visually separated from the list section by a border line
+  ```sh
+  # No separator shown below the header border
+  fzf --style full --input-border none --header foo
+
+  # Separator shown; no border separates the input section from the list section
+  fzf --style full --input-border none --header foo --no-header-border
+
+  # No separator below the border of the preview window at 'next' position
+  fzf --preview : --preview-window next
+
+  # Conversely, separator is now shown when the input border does not draw
+  # a line facing the list section
+  fzf --input-border bottom
+  ```
 - Rendering improvements
     - Each frame is now wrapped in synchronized update mode (mode 2026) to reduce flickering on supported terminals
     - Reduced rendering output by 10-23% by skipping redundant SGR sequences

Gemfile.lock

@@ -2,7 +2,7 @@ GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.2)
-    json (2.9.1)
+    json (2.19.9)
     language_server-protocol (3.17.0.3)
     minitest (5.25.4)
     parallel (1.26.3)

Makefile

@@ -97,6 +97,16 @@ test: $(SOURCES)
 itest:
 	ruby test/runner.rb
 
+# Actively fuzz the matcher fast paths against the general algorithm.
+# Go fuzzes one target at a time, so iterate. Override duration with
+# FUZZTIME (e.g. make fuzz FUZZTIME=5m).
+FUZZTIME ?= 30s
+fuzz:
+	@for t in FuzzFuzzyMatchV2Single FuzzFuzzyMatchV2Two; do \
+		echo "== $$t =="; \
+		$(GO) test -run '^$$' -fuzz "^$$t$$" -fuzztime $(FUZZTIME) ./src/algo || exit 1; \
+	done
+
 bench:
 	cd src && SHELL=/bin/sh GOOS= $(GO) test -v -tags "$(TAGS)" -run=Bench -bench=. -benchmem
 

RELEASE.md

@@ -18,7 +18,7 @@ triggered by a tag push.
 2. Verify file consistency, sign the tag, and push the tag.
 
     ```sh
-    make tag VERSION=0.74.0
+    make tag VERSION=0.74.2
     ```
 
     `make tag` runs `prerelease` first (checks that the version

go.mod

@@ -4,7 +4,7 @@ require (
 	github.com/charlievieth/fastwalk v1.0.14
 	github.com/gdamore/tcell/v2 v2.9.0
 	github.com/junegunn/go-shellwords v0.0.0-20250127100254-2aa3b3277741
-	github.com/mattn/go-isatty v0.0.22
+	github.com/mattn/go-isatty v0.0.24
 	github.com/rivo/uniseg v0.4.7
 	golang.org/x/sys v0.35.0
 	golang.org/x/term v0.34.0

go.sum

@@ -8,8 +8,8 @@ github.com/junegunn/go-shellwords v0.0.0-20250127100254-2aa3b3277741 h1:7dYDtfMD
 github.com/junegunn/go-shellwords v0.0.0-20250127100254-2aa3b3277741/go.mod h1:6EILKtGpo5t+KLb85LNZLAF6P9LKp78hJI80PXMcn3c=
 github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY=
 github.com/lucasb-eyer/go-colorful v1.2.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
-github.com/mattn/go-isatty v0.0.22 h1:j8l17JJ9i6VGPUFUYoTUKPSgKe/83EYU2zBC7YNKMw4=
+github.com/mattn/go-isatty v0.0.24 h1:tGZZoVgT/KiqK1c8ocVLeDS8BSWMRd47J3Lbz7vsReI=
-github.com/mattn/go-isatty v0.0.22/go.mod h1:ZXfXG4SQHsB/w3ZeOYbR0PrPwLy+n6xiMrJlRFqopa4=
+github.com/mattn/go-isatty v0.0.24/go.mod h1:nMCL3Zebbrt45jsMDgnfIwz6ydEQApk5oEI3HqDio6A=
 github.com/mattn/go-runewidth v0.0.16 h1:E5ScNMtiwvlvB5paMFdw9p4kSQzbXFikJ5SQO6TULQc=
 github.com/mattn/go-runewidth v0.0.16/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=

install

@@ -2,7 +2,7 @@
 
 set -u
 
-version=0.74.0
+version=0.74.2
 auto_completion=
 key_bindings=
 update_config=2

install.ps1

@@ -1,4 +1,4 @@
-$version="0.74.0"
+$version="0.74.2"
 
 $fzf_base=Split-Path -Parent $MyInvocation.MyCommand.Definition
 

man/man1/fzf-tmux.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf\-tmux 1 "Jul 2026" "fzf 0.74.0" "fzf\-tmux - open fzf in tmux split pane"
+.TH fzf\-tmux 1 "Aug 2026" "fzf 0.74.2" "fzf\-tmux - open fzf in tmux split pane"
 
 .SH NAME
 fzf\-tmux - open fzf in tmux split pane

man/man1/fzf.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf 1 "Jul 2026" "fzf 0.74.0" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "Aug 2026" "fzf 0.74.2" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -426,9 +426,13 @@ On tmux 3.7 or above and on Zellij, the floating pane is not modal; you can
 switch to other panes and windows while fzf is running, and move and resize
 the pane with the mouse. The native border of the pane is the handle for
 moving and resizing it, so it is used by default and \fBborder\-native\fR is
-implied. On tmux, \fB\-\-border\-label\fR is set as the title of the pane,
+implied. \fB\-\-border\-label\fR is displayed on the native border, and
-and is displayed on the border if \fBpane\-border\-status\fR is enabled in
+\fBchange\-border\-label\fR and \fBtransform\-border\-label\fR update it
-tmux (\fB\-\-border\-label\-pos\fR is ignored).
+(\fB\-\-border\-label\-pos\fR is ignored). On tmux, fzf holds the label in
+the \fB@fzf\-border\-label\fR option of the pane and sets its
+\fBpane\-border\-format\fR to read it back, so the label is displayed if
+\fBpane\-border\-status\fR is enabled in tmux. The title of the pane is left
+alone. On Zellij, the label is the name of the pane.
 
 fzf draws its own border instead when a border style is explicitly specified
 with \fB\-\-border\fR, so that it is the only border shown. \fBnone\fR and
@@ -823,6 +827,10 @@ A synonym for \fB\-\-info=hidden\fB
 The given string will be repeated to form the horizontal separator on the info
 line (default: '─' or '\-' depending on \fB\-\-no\-unicode\fR).
 
+Unless explicitly specified, the separator is not displayed if the input
+section is already visually separated from the list section by a border line
+(e.g. \fB\-\-input\-border\fR or \fB\-\-header\-border\fR).
+
 ANSI color codes are supported.
 
 .TP

shell/key-bindings.fish

@@ -127,14 +127,21 @@ function fzf_key_bindings
     set -l -- total_lines (count $command_line)
     set -l -- fzf_query (string escape -- $command_line[$current_line])
 
+    set -lx -- FZF_DEFAULT_COMMAND "builtin history -z --show-time=(set_color $fish_color_comment 2>/dev/null; or set_color normal)\"%F %a %T%t%s%t\"(set_color normal)"
+
+    # Enable syntax highlighting colors on fish v4.3.3 and newer
+    if string match -qr -- '^\\d\\d+|^4\\.[4-9]|^4\\.3\\.[3-9]' $version
+      set -a -- FZF_DEFAULT_COMMAND "--color=always"
+    end
+
     set -lx -- FZF_DEFAULT_OPTS (__fzf_defaults '' \
       '--with-nth=2.. --nth=2..,.. --scheme=history --multi --no-multi-line' \
       '--no-wrap --wrap-sign="\t\t\t↳ " --preview-wrap-sign="↳ " --freeze-left=1' \
       '--bind="alt-enter:become(set -g fzf_temp {+sf3..}; string join0 -- (string split0 -- <$fzf_temp | fish_indent -i); unlink $fzf_temp &>/dev/null)"' \
       '--bind="alt-t:change-with-nth(1,3..|3..|2..)"' \
-      '--bind="shift-delete:execute-silent(eval builtin history delete -Ce -- (string escape -n -- (string split0 -- <{+sf3..})))+reload(eval $FZF_DEFAULT_COMMAND)"' \
+      "--bind='shift-delete:execute-silent(eval builtin history delete -Ce -- (string escape -n -- (string split0 -- <{+sf3..})))+reload($FZF_DEFAULT_COMMAND)'" \
       "--bind=ctrl-r:toggle-sort,alt-r:toggle-raw --highlight-line $FZF_CTRL_R_OPTS" \
-      '--accept-nth=3.. --delimiter="\t" --tabstop=4 --read0 --print0 --with-shell='(status fish-path)\\ -c)
+      '--accept-nth=3.. --delimiter="\t" --tabstop=4 --ansi --read0 --print0 --with-shell='(status fish-path)\\ -c)
 
     # Add dynamic preview options if preview command isn't already set by user
     if string match -qvr -- '--preview[= ]' "$FZF_DEFAULT_OPTS"
@@ -147,16 +154,6 @@ function fzf_key_bindings
 
     set -lx FZF_DEFAULT_OPTS_FILE
 
-    set -lx -- FZF_DEFAULT_COMMAND 'builtin history -z'
-
-    # Enable syntax highlighting colors on fish v4.3.3 and newer
-    if string match -qr -- '^\\d\\d+|^4\\.[4-9]|^4\\.3\\.[3-9]' $version
-      set -a -- FZF_DEFAULT_OPTS '--ansi'
-      set -a -- FZF_DEFAULT_COMMAND '--color=always --show-time=(set_color $fish_color_comment 2>/dev/null; or set_color normal)"%F %a %T%t%s%t"(set_color normal)'
-    else
-      set -a -- FZF_DEFAULT_COMMAND '--show-time="%F %a %T%t%s%t"'
-    end
-
     # Merge history from other sessions before searching
     test -z "$fish_private_mode"; and builtin history merge
 

shell/key-bindings.zsh

@@ -115,7 +115,7 @@ fzf-cd-widget() {
   # working directory.
   # If failed, fallback to the unexpanded path to surface the error to the user.
   # NOTE: Don't use the `:a` modifier as it resolves symlinks like `pwd -P`.
-  dir=$(builtin cd >/dev/null -- "${dir}" && echo "${PWD}" || echo "${dir}")
+  dir=$(builtin cd -q >/dev/null -- "${dir}" && echo "${PWD}" || echo "${dir}")
   zle push-line # Clear buffer. Auto-restored on next prompt.
   BUFFER="builtin cd -- ${(q)dir}"
   zle accept-line
@@ -139,11 +139,11 @@ fzf-history-widget() {
   # as the associative 'history' array, which maps event numbers to full history
   # lines, are set. Also, make sure Perl is installed for multi-line output.
   if zmodload -F zsh/parameter p:{commands,history} 2>/dev/null && (( ${+commands[perl]} )); then
+    extracted_with_perl=1
     selected="$(printf '%s\t%s\000' "${(kv)history[@]}" |
       perl -0 -ne 'if (!$seen{(/^\s*[0-9]+\**\t(.*)/s, $1)}++) { s/\n/\n\t/g; print; }' |
       FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '\t↳ ' --highlight-line --multi ${FZF_CTRL_R_OPTS-} --query=${(qqq)LBUFFER} --read0") \
       FZF_DEFAULT_OPTS_FILE='' $(__fzfcmd))"
-      extracted_with_perl=1
   else
     selected="$(fc -rl 1 | __fzf_exec_awk '{ cmd=$0; sub(/^[ \t]*[0-9]+\**[ \t]+/, "", cmd); if (!seen[cmd]++) print $0 }' |
       FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '\t↳ ' --highlight-line --multi ${FZF_CTRL_R_OPTS-} --query=${(qqq)LBUFFER}") \

src/algo/algo.go

@@ -425,6 +425,217 @@ func debugV2(T []rune, pattern []rune, F []int32, lastIdx int, H []int16, C []in
 	}
 }
 
+// fuzzyMatchV2Single is a fast path for a single-character ASCII pattern on
+// ASCII input. Same scoring and tiebreaks as Phase 2 of FuzzyMatchV2, but
+// jumps between occurrences instead of scanning every character, and
+// allocates no arrays.
+func fuzzyMatchV2Single(caseSensitive bool, forward bool, input *util.Chars, b byte, withPos bool) (Result, *[]int) {
+	byteArray := input.Bytes()
+	maxScore, maxScorePos := int16(0), -1
+	for idx := 0; idx < len(byteArray); {
+		idx = trySkip(input, caseSensitive, b, idx)
+		if idx < 0 {
+			break
+		}
+		class := asciiCharClasses[byteArray[idx]]
+		prevClass := initialCharClass
+		if idx > 0 {
+			prevClass = asciiCharClasses[byteArray[idx-1]]
+		}
+		bonus := bonusMatrix[prevClass][class]
+		score := scoreMatch + bonus*bonusFirstCharMultiplier
+		if forward && score > maxScore || !forward && score >= maxScore {
+			maxScore, maxScorePos = score, idx
+			if forward && bonus >= bonusBoundary {
+				break
+			}
+		}
+		idx++
+	}
+	if maxScorePos < 0 {
+		return Result{-1, -1, 0}, nil
+	}
+	result := Result{maxScorePos, maxScorePos + 1, int(maxScore)}
+	if !withPos {
+		return result, nil
+	}
+	pos := []int{maxScorePos}
+	return result, &pos
+}
+
+// Test hooks: force the general path instead of a fast path, so the two can
+// be compared for equivalence.
+var (
+	disableSingle bool
+	disableTwo    bool
+)
+
+// fuzzyMatchV2Two is a fused fast path for a two-character ASCII pattern on
+// ASCII input. It replicates Phase 2 (row 0) and Phase 3 (row 1) of
+// FuzzyMatchV2 in a single pass, carrying the row-0 diagonal/left values and
+// the row-1 left value as scalars instead of materializing score arrays.
+// When withPos is set, the two DP rows are stored so the backtrace can
+// recover the matched character positions, exactly as the general Phase 4.
+func fuzzyMatchV2Two(caseSensitive bool, forward bool, input *util.Chars, pchar0 byte, pchar1 byte, minIdx int, maxIdx int, withPos bool, slab *util.Slab) (Result, *[]int) {
+	sl := input.Bytes()
+	N := maxIdx - minIdx
+
+	// Row storage, only needed for the backtrace
+	var H0, C0, H1, C1 []int16
+	if withPos {
+		o := 0
+		o, H0 = alloc16(o, slab, N)
+		o, C0 = alloc16(o, slab, N)
+		o, H1 = alloc16(o, slab, N)
+		_, C1 = alloc16(o, slab, N)
+	}
+
+	maxScore, maxScorePos := int16(0), 0
+	prevClass := initialCharClass
+
+	// Subsequence tracking (equivalent to F[0], F[1] in Phase 2). The scope
+	// from asciiFuzzyIndex ends exactly at the last pchar1, so row 1's upper
+	// bound (Phase 3 lastIdx) is the final loop position; no separate var.
+	f0, f1 := -1, -1
+
+	// Row 0 running state at the previous position
+	var h0Prev, c0Prev, bPrev int16
+	inGap0 := false
+
+	// Row 1 running state
+	var h1Prev int16
+	inGap1 := false
+
+	for off := range N {
+		pos := minIdx + off
+		b := sl[pos]
+		class := asciiCharClasses[b]
+		lb := b
+		if !caseSensitive && b >= 'A' && b <= 'Z' {
+			lb = b + 32
+		}
+		bonus := bonusMatrix[prevClass][class]
+		prevClass = class
+
+		// Subsequence advance: pchar0 then pchar1
+		if f0 < 0 {
+			if lb == pchar0 {
+				f0 = off
+			}
+		} else if lb == pchar1 && f1 < 0 {
+			f1 = off
+		}
+
+		// Row 0 (pchar0)
+		var h0Cur, c0Cur int16
+		if lb == pchar0 {
+			h0Cur = scoreMatch + bonus*bonusFirstCharMultiplier
+			c0Cur = 1
+			inGap0 = false
+		} else {
+			if inGap0 {
+				h0Cur = max(h0Prev+scoreGapExtension, 0)
+			} else {
+				h0Cur = max(h0Prev+scoreGapStart, 0)
+			}
+			c0Cur = 0
+			inGap0 = true
+		}
+		if withPos {
+			H0[off], C0[off] = h0Cur, c0Cur
+		}
+
+		// Row 1 (pchar1), only within [f1, lastIdx]
+		if f1 >= 0 && off >= f1 {
+			var s1, s2, consecutive int16
+			hleft := h1Prev
+			if off == f1 {
+				hleft = 0
+			}
+			if inGap1 {
+				s2 = hleft + scoreGapExtension
+			} else {
+				s2 = hleft + scoreGapStart
+			}
+			if lb == pchar1 {
+				s1 = h0Prev + scoreMatch
+				bb := bonus
+				consecutive = c0Prev + 1
+				if consecutive > 1 {
+					fb := bPrev
+					if bb >= bonusBoundary && bb > fb {
+						consecutive = 1
+					} else {
+						bb = max(bb, bonusConsecutive, fb)
+					}
+				}
+				if s1+bb < s2 {
+					s1 += bonus
+					consecutive = 0
+				} else {
+					s1 += bb
+				}
+			}
+			inGap1 = s1 < s2
+			score := max(s1, s2, 0)
+			if forward && score > maxScore || !forward && score >= maxScore {
+				maxScore, maxScorePos = score, off
+			}
+			h1Prev = score
+			if withPos {
+				H1[off], C1[off] = score, consecutive
+			}
+		}
+
+		h0Prev, c0Prev, bPrev = h0Cur, c0Cur, bonus
+	}
+
+	if f1 < 0 {
+		return Result{-1, -1, 0}, nil
+	}
+	if !withPos {
+		return Result{minIdx + f0, minIdx + maxScorePos + 1, int(maxScore)}, nil
+	}
+
+	// Phase 4 backtrace, specialized to two rows. Mirrors the general loop:
+	// record a cell when it dominates its diagonal and left neighbors, then
+	// step up a row; otherwise step left. preferMatch breaks score ties and
+	// must not read row 1 left of f1 (unwritten, possibly stale slab data).
+	pos := posArray(true, 2)
+	i := 1
+	j := maxScorePos
+	preferMatch := true
+	for {
+		var s, s1, s2, cCur int16
+		if i == 1 {
+			s, cCur = H1[j], C1[j]
+			if j >= f1 {
+				s1 = H0[j-1]
+			}
+			if j > f1 {
+				s2 = H1[j-1]
+			}
+		} else {
+			s, cCur = H0[j], C0[j]
+			if j > f0 {
+				s2 = H0[j-1]
+			}
+		}
+		row := i
+		if s > s1 && (s > s2 || s == s2 && preferMatch) {
+			*pos = append(*pos, j+minIdx)
+			if i == 0 {
+				break
+			}
+			i--
+		}
+		preferMatch = cCur > 1 ||
+			row == 0 && j < N-1 && j+1 >= f1 && C1[j+1] > 0
+		j--
+	}
+	return Result{minIdx + j, minIdx + maxScorePos + 1, int(maxScore)}, pos
+}
+
 func FuzzyMatchV2(caseSensitive bool, normalize bool, forward bool, input *util.Chars, pattern []rune, withPos bool, slab *util.Slab) (Result, *[]int) {
 	// Assume that pattern is given in lowercase if case-insensitive.
 	// First check if there's a match and calculate bonus for each position.
@@ -447,6 +658,12 @@ func FuzzyMatchV2(caseSensitive bool, normalize bool, forward bool, input *util.
 		return FuzzyMatchV1(caseSensitive, normalize, forward, input, pattern, withPos, slab)
 	}
 
+	// Single-character ASCII pattern needs neither the prefilter nor the
+	// score matrix
+	if !disableSingle && M == 1 && input.IsBytes() && pattern[0] < utf8.RuneSelf {
+		return fuzzyMatchV2Single(caseSensitive, forward, input, byte(pattern[0]), withPos)
+	}
+
 	// Phase 1. Optimized search for ASCII string
 	minIdx, maxIdx := asciiFuzzyIndex(input, pattern, caseSensitive)
 	if minIdx < 0 {
@@ -455,6 +672,13 @@ func FuzzyMatchV2(caseSensitive bool, normalize bool, forward bool, input *util.
 	// fmt.Println(N, maxIdx, idx, maxIdx-idx, input.ToString())
 	N = maxIdx - minIdx
 
+	// Two-character ASCII pattern: rows 0 and 1 collapse to scalar running
+	// state, so the general score arrays are unnecessary
+	if !disableTwo && M == 2 && input.IsBytes() &&
+		pattern[0] < utf8.RuneSelf && pattern[1] < utf8.RuneSelf {
+		return fuzzyMatchV2Two(caseSensitive, forward, input, byte(pattern[0]), byte(pattern[1]), minIdx, maxIdx, withPos, slab)
+	}
+
 	// Reuse pre-allocated integer slice to avoid unnecessary sweeping of garbages
 	offset16 := 0
 	offset32 := 0
@@ -630,6 +854,7 @@ func FuzzyMatchV2(caseSensitive bool, normalize bool, forward bool, input *util.
 				s2 = H[I+j0-1]
 			}
 
+			row := i
 			if s > s1 && (s > s2 || s == s2 && preferMatch) {
 				*pos = append(*pos, j+minIdx)
 				if i == 0 {
@@ -637,7 +862,10 @@ func FuzzyMatchV2(caseSensitive bool, normalize bool, forward bool, input *util.
 				}
 				i--
 			}
-			preferMatch = C[I+j0] > 1 || I+width+j0+1 < len(C) && C[I+width+j0+1] > 0
+			// Row below is only written from column F[row+1]; don't read
+			// stale slab data left of it
+			preferMatch = C[I+j0] > 1 ||
+				row+1 < M && j < lastIdx && int32(j+1) >= F[row+1] && C[I+width+j0+1] > 0
 			j--
 		}
 	}

src/algo/algo_test.go

@@ -218,3 +218,98 @@ func TestLongStringWithNormalize(t *testing.T) {
 	unicodeString := string(bytes) + " Minímal example"
 	assertMatch2(t, FuzzyMatchV1, false, true, false, unicodeString, "minim", 30001, 30006, 140)
 }
+
+func TestResultPositionsWithReusedSlab(t *testing.T) {
+	// Backtrace positions in equal-score ties must not depend on data
+	// a previous match left in the slab
+	pattern := []rune("co/")
+	target := util.ToChars([]byte("core_color/view/server.txt"))
+	_, freshPos := FuzzyMatchV2(false, false, true, &target, pattern, true, util.MakeSlab(100*1024, 2048))
+
+	slab := util.MakeSlab(100*1024, 2048)
+	dirty := util.ToChars([]byte("completion/keybinding/client/handler/writer_index.txt"))
+	FuzzyMatchV2(false, false, true, &dirty, pattern, true, slab)
+	_, reusedPos := FuzzyMatchV2(false, false, true, &target, pattern, true, slab)
+
+	if len(*freshPos) != len(*reusedPos) {
+		t.Fatalf("position count mismatch: %v vs %v", *freshPos, *reusedPos)
+	}
+	for i := range *freshPos {
+		if (*freshPos)[i] != (*reusedPos)[i] {
+			t.Errorf("positions differ with reused slab: %v vs %v", *freshPos, *reusedPos)
+			break
+		}
+	}
+}
+
+// TestFuzzyMatchV2TwoEquivalence verifies that the two-character fast path
+// produces the same Result and positions as the general algorithm across
+// case sensitivity, direction, and withPos, using a reused slab to surface
+// any stale-data reads in the backtrace.
+func TestFuzzyMatchV2TwoEquivalence(t *testing.T) {
+	words := []string{"src", "main", "core", "config", "parser", "render", "server",
+		"client", "index", "handler", "util", "list", "cache", "reader"}
+	exts := []string{".go", ".rb", ".py", ".md", ".c", ".txt"}
+	// Deterministic corpus (LCG), plus adversarial short/repeated items
+	corpus := []util.Chars{}
+	seed := uint32(12345)
+	next := func(n int) int { seed = seed*1664525 + 1013904223; return int(seed>>8) % n }
+	for i := 0; i < 4000; i++ {
+		depth := 2 + next(4)
+		s := ""
+		for d := 0; d < depth; d++ {
+			if d > 0 {
+				s += "/"
+			}
+			s += words[next(len(words))]
+			if next(5) == 0 {
+				s += "_" + words[next(len(words))]
+			}
+		}
+		s += exts[next(len(exts))]
+		corpus = append(corpus, util.ToChars([]byte(s)))
+	}
+	for _, s := range []string{"", "a", "ab", "aa", "aXb", "a/b", "//", "..", "abcabc",
+		"AaBb", "x.y.z", "a_b_c", "CoreCore", "  co"} {
+		corpus = append(corpus, util.ToChars([]byte(s)))
+	}
+
+	pats := []string{"co", "ab", "aa", "//", "..", "sr", "a/", "_c", "oo", "Ab",
+		"z.", "b.", "1a", "ll", "re", "er", "Co"}
+	slab := util.MakeSlab(100*1024, 2048)
+	for _, cs := range []bool{false, true} {
+		for _, fwd := range []bool{true, false} {
+			for _, wp := range []bool{false, true} {
+				for _, p := range pats {
+					pattern := []rune(p)
+					for j := range corpus {
+						disableTwo = true
+						rg, pg := FuzzyMatchV2(cs, false, fwd, &corpus[j], pattern, wp, slab)
+						disableTwo = false
+						rt, pt := FuzzyMatchV2(cs, false, fwd, &corpus[j], pattern, wp, slab)
+						if rg != rt {
+							t.Fatalf("Result cs=%v fwd=%v wp=%v pat=%q item=%q: general %v vs two %v",
+								cs, fwd, wp, p, corpus[j].ToString(), rg, rt)
+						}
+						if (pg == nil) != (pt == nil) || (pg != nil && !equalInts(*pg, *pt)) {
+							t.Fatalf("Pos cs=%v fwd=%v wp=%v pat=%q item=%q: general %v vs two %v",
+								cs, fwd, wp, p, corpus[j].ToString(), pg, pt)
+						}
+					}
+				}
+			}
+		}
+	}
+}
+
+func equalInts(a, b []int) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i := range a {
+		if a[i] != b[i] {
+			return false
+		}
+	}
+	return true
+}

src/algo/fastpath_equiv_test.go

@@ -0,0 +1,157 @@
+package algo
+
+// Equivalence tests for the single- and two-character fast paths against the
+// general FuzzyMatchV2 algorithm, which serves as the oracle.
+//
+// Two complementary strategies:
+//   - Exhaustive: every string up to a fixed length over an alphabet that
+//     covers all ASCII character classes, so every local scoring branch is
+//     exercised (not merely sampled).
+//   - Fuzz: coverage-guided, arbitrary length, to reach cases the bounded
+//     exhaustive sweep cannot (e.g. long gaps where a high score decays).
+
+import (
+	"testing"
+
+	"github.com/junegunn/fzf/src/util"
+)
+
+// One char of each ASCII class that affects scoring: lower, upper, delimiter,
+// number, non-word, whitespace.
+var equivAlphabet = []byte{'a', 'B', '/', '1', '_', ' '}
+
+func samePos(a, b *[]int) bool {
+	if (a == nil) != (b == nil) {
+		return false
+	}
+	if a == nil {
+		return true
+	}
+	return equalInts(*a, *b)
+}
+
+// compareFastPath runs a single input/pattern/params pair through both the
+// fast path and the general algorithm and fails on any difference.
+// It toggles the package-global disable* hook, so tests that call it must
+// not run in parallel.
+func compareFastPath(t *testing.T, chars *util.Chars, pattern []rune, cs, norm, fwd, wp bool, disable *bool, slab *util.Slab) {
+	t.Helper()
+	*disable = true
+	rg, pg := FuzzyMatchV2(cs, norm, fwd, chars, pattern, wp, slab)
+	*disable = false
+	rt, pt := FuzzyMatchV2(cs, norm, fwd, chars, pattern, wp, slab)
+	if rg != rt || !samePos(pg, pt) {
+		t.Fatalf("mismatch item=%q pat=%q cs=%v norm=%v fwd=%v wp=%v: general %v %v vs fast %v %v",
+			chars.ToString(), string(pattern), cs, norm, fwd, wp, rg, pg, rt, pt)
+	}
+}
+
+// lowerPattern lowercases the pattern for case-insensitive search, matching
+// the Algo contract (the pattern is pre-lowercased by BuildPattern).
+func lowerPattern(p []rune, cs bool) []rune {
+	if cs {
+		return p
+	}
+	out := make([]rune, len(p))
+	for i, c := range p {
+		if c >= 'A' && c <= 'Z' {
+			c += 32
+		}
+		out[i] = c
+	}
+	return out
+}
+
+func runExhaustive(t *testing.T, patLen, maxLen int, disable *bool) {
+	// All patterns of length patLen over the alphabet
+	var pats [][]rune
+	var genPat func(cur []rune)
+	genPat = func(cur []rune) {
+		if len(cur) == patLen {
+			pats = append(pats, append([]rune(nil), cur...))
+			return
+		}
+		for _, c := range equivAlphabet {
+			genPat(append(cur, rune(c)))
+		}
+	}
+	genPat(nil)
+
+	slab := util.MakeSlab(100*1024, 2048)
+	buf := make([]byte, 0, maxLen)
+	var rec func(depth int)
+	rec = func(depth int) {
+		chars := util.ToChars(append([]byte(nil), buf...))
+		// normalize is not varied: normalizeRune is the identity below 0xC0,
+		// and the general algorithm skips normalization on its ASCII branch,
+		// so it cannot change the result for the ASCII-only fast path. The
+		// fuzz test exercises normalize=true as a guard against that changing.
+		for _, cs := range []bool{false, true} {
+			for _, fwd := range []bool{true, false} {
+				for _, wp := range []bool{false, true} {
+					for _, p := range pats {
+						compareFastPath(t, &chars, lowerPattern(p, cs), cs, false, fwd, wp, disable, slab)
+					}
+				}
+			}
+		}
+		if depth == maxLen {
+			return
+		}
+		for _, c := range equivAlphabet {
+			buf = append(buf, c)
+			rec(depth + 1)
+			buf = buf[:len(buf)-1]
+		}
+	}
+	rec(0)
+}
+
+func TestFuzzyMatchV2SingleExhaustive(t *testing.T) {
+	runExhaustive(t, 1, 6, &disableSingle)
+}
+
+func TestFuzzyMatchV2TwoExhaustive(t *testing.T) {
+	runExhaustive(t, 2, 6, &disableTwo)
+}
+
+func fuzzFastPath(f *testing.F, patLen int, disable *bool) {
+	inputs := []string{"core_color/view/server.txt", "a                        b",
+		"XyZ/123_abc.def", "aaaaaaaaaaaaaaaaaaaaaaaa"}
+	// Seed patterns of the right length; wrong-length seeds are rejected below
+	// and would waste the corpus.
+	seedPats := map[int][]string{1: {"c", "a", "/"}, 2: {"co", "ab", "z1", "aa"}}[patLen]
+	for _, in := range inputs {
+		for _, p := range seedPats {
+			f.Add(in, p)
+		}
+	}
+	slab := util.MakeSlab(200*1024, 4096)
+	f.Fuzz(func(t *testing.T, input, pat string) {
+		r := []rune(pat)
+		if len(r) != patLen {
+			return
+		}
+		for _, c := range r {
+			if c >= 128 {
+				return
+			}
+		}
+		chars := util.ToChars([]byte(input))
+		if !chars.IsBytes() {
+			return
+		}
+		for _, cs := range []bool{false, true} {
+			for _, norm := range []bool{false, true} {
+				for _, fwd := range []bool{true, false} {
+					for _, wp := range []bool{false, true} {
+						compareFastPath(t, &chars, lowerPattern(r, cs), cs, norm, fwd, wp, disable, slab)
+					}
+				}
+			}
+		}
+	})
+}
+
+func FuzzFuzzyMatchV2Single(f *testing.F) { fuzzFastPath(f, 1, &disableSingle) }
+func FuzzFuzzyMatchV2Two(f *testing.F)    { fuzzFastPath(f, 2, &disableTwo) }

src/options.go

@@ -3696,7 +3696,10 @@ func (opts *Options) noSeparatorLine() bool {
 	if opts.Inputless {
 		return true
 	}
-	sep := opts.Separator == nil && !opts.InputBorderShape.Visible() || opts.Separator != nil && len(*opts.Separator) > 0
+	// NOTE: This does not know that the default separator can be suppressed at
+	// runtime (see Terminal.separatorLength), so the minimum heights derived
+	// from it can be one line taller than strictly necessary.
+	sep := opts.Separator == nil && !inputBorderFacesList(opts.Layout, opts.InputBorderShape) || opts.Separator != nil && len(*opts.Separator) > 0
 	return noSeparatorLine(opts.InfoStyle, sep)
 }
 

src/proxy.go

@@ -11,6 +11,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/junegunn/fzf/src/tui"
@@ -19,10 +20,75 @@ import (
 
 const becomeSuffix = ".become"
 
+// Withheld from the environment replay below, so an outer value cannot
+// override what the floating pane set
+const internalEnvPrefix = "__FZF_INTERNAL_"
+
 func escapeSingleQuote(str string) string {
 	return "'" + strings.ReplaceAll(str, "'", "'\\''") + "'"
 }
 
+// Read and remove, so preview and execute commands do not inherit it
+func takeEnv(name string) string {
+	value := os.Getenv(name)
+	os.Unsetenv(name)
+	return value
+}
+
+// Applies label updates off the event loop, which would block on the fork
+type labelUpdater struct {
+	set     func(string)
+	mu      sync.Mutex
+	pending *string
+	running bool
+}
+
+// A queue of one: a burst collapses to the newest label. A goroutine per
+// update could apply them out of order
+func (u *labelUpdater) update(label string) {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	u.pending = &label
+	if u.running {
+		return
+	}
+	u.running = true
+	go u.run()
+}
+
+// Ends once caught up, so nothing needs cancelling when Run returns
+func (u *labelUpdater) run() {
+	for {
+		u.mu.Lock()
+		label := u.pending
+		if label == nil {
+			u.running = false
+			u.mu.Unlock()
+			return
+		}
+		u.pending = nil
+		u.mu.Unlock()
+		u.set(*label)
+	}
+}
+
+// Updates the label on the native border, or nil when it is not fzf's to update
+func nativeLabelSetter() func(string) {
+	// Read both, so neither is left behind
+	tmuxPane, zellijPane := takeEnv(tmuxBorderLabelEnv), takeEnv(zellijBorderLabelEnv)
+	var set func(string)
+	switch {
+	case tmuxPane != "":
+		set = func(label string) { setTmuxBorderLabel(tmuxPane, label) }
+	case zellijPane != "":
+		set = func(label string) { setZellijBorderLabel(zellijPane, label) }
+	default:
+		return nil
+	}
+	updater := &labelUpdater{set: set}
+	return updater.update
+}
+
 func popupArgStr(args []string, opts *Options) (string, string) {
 	fzf, rest := args[0], args[1:]
 	args = []string{"--bind=ctrl-z:ignore"}
@@ -125,6 +191,9 @@ func runProxy(commandPrefix string, cmdBuilder func(temp string, needBash bool)
 		validIdentifier := regexp.MustCompile(`^[a-zA-Z_][a-zA-Z0-9_]*$`)
 		for _, pairStr := range os.Environ() {
 			pair := strings.SplitN(pairStr, "=", 2)
+			if strings.HasPrefix(pair[0], internalEnvPrefix) {
+				continue
+			}
 			if validIdentifier.MatchString(pair[0]) {
 				exports = append(exports, fmt.Sprintf("export %s=%s", pair[0], escapeSingleQuote(pair[1])))
 			} else if strings.HasPrefix(pair[0], "BASH_FUNC_") && strings.HasSuffix(pair[0], "%%") {

src/proxy_test.go

@@ -0,0 +1,65 @@
+package fzf
+
+import (
+	"strconv"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestLabelUpdater(t *testing.T) {
+	var mu sync.Mutex
+	applied := []int{}
+	// The goroutine can still be running after the test function returns, so
+	// it records the label instead of reporting it, and -1 stands in for one
+	// that could not be parsed
+	updater := &labelUpdater{set: func(label string) {
+		n, err := strconv.Atoi(label)
+		if err != nil {
+			n = -1
+		}
+		mu.Lock()
+		applied = append(applied, n)
+		mu.Unlock()
+		// Long enough for the burst to pile up behind the first update
+		time.Sleep(time.Millisecond)
+	}}
+
+	const last = 99
+	for i := 0; i <= last; i++ {
+		updater.update(strconv.Itoa(i))
+	}
+
+	// However many updates are dropped, the final one is always applied
+	deadline := time.Now().Add(5 * time.Second)
+	for {
+		mu.Lock()
+		done := len(applied) > 0 && applied[len(applied)-1] == last
+		mu.Unlock()
+		if done {
+			break
+		}
+		if time.Now().After(deadline) {
+			t.Fatalf("last update was not applied: %v", applied)
+		}
+		time.Sleep(time.Millisecond)
+	}
+
+	mu.Lock()
+	defer mu.Unlock()
+	// Updates are never applied out of order, so the border cannot be left
+	// showing a label older than the last one requested
+	for i, n := range applied {
+		if i > 0 && n <= applied[i-1] {
+			t.Errorf("applied out of order: %v", applied)
+			break
+		}
+	}
+	// A burst collapses instead of running one command per update. The
+	// updates are queued in a tight loop while each one takes a millisecond
+	// to apply, so all of them landing would mean no coalescing at all
+	if len(applied) >= last+1 {
+		t.Errorf("expected updates to be coalesced, applied all %d", len(applied))
+	}
+	t.Logf("applied %d of %d updates", len(applied), last+1)
+}

src/result.go

@@ -369,9 +369,21 @@ func radixSortResults(a []Result, tac bool, scratch []Result) []Result {
 	src, dst := a, buf
 	scattered := 0
 
+	// OR of all keys: a byte position that is zero here is zero in every key,
+	// so its pass is a no-op and can be skipped without a histogram scan.
+	// With the common two-criteria setup the low 32 bits are always zero.
+	var keyOR uint64
+	for i := range src {
+		keyOR |= sortKey(&src[i])
+	}
+
 	for pass := range 8 {
 		shift := uint(pass) * 8
 
+		if byte(keyOR>>shift) == 0 {
+			continue
+		}
+
 		var count [256]int
 		for i := range src {
 			count[byte(sortKey(&src[i])>>shift)]++

src/terminal.go

@@ -57,8 +57,11 @@ var offsetComponentRegex *regexp.Regexp
 var offsetTrimCharsRegex *regexp.Regexp
 var passThroughBeginRegex *regexp.Regexp
 var passThroughEndTmuxRegex *regexp.Regexp
+var sixelBeginRegex *regexp.Regexp
 var ttyin *os.File
 
+var inTmux = len(os.Getenv("TMUX")) > 0
+
 const clearCode string = "\x1b[2J"
 
 // Number of maximum focus events to process synchronously
@@ -92,6 +95,7 @@ func init() {
 	*/
 	passThroughBeginRegex = regexp.MustCompile(`\x1bPtmux;\x1b\x1b|\x1b(_G|P[0-9;]*q)|\x1b]1337;`)
 	passThroughEndTmuxRegex = regexp.MustCompile(`[^\x1b]\x1b\\`)
+	sixelBeginRegex = regexp.MustCompile(`^\x1bP[0-9;]*q`)
 }
 
 type jumpMode int
@@ -271,6 +275,7 @@ type Terminal struct {
 	ghost                string
 	separator            labelPrinter
 	separatorLen         int
+	separatorAuto        bool
 	spinner              []string
 	promptString         string
 	prompt               func()
@@ -467,6 +472,7 @@ type Terminal struct {
 	clickFooterLine      int
 	clickFooterColumn    int
 	proxyScript          string
+	setNativeLabel       func(string)
 	numLinesCache        map[int32]numLinesCacheValue
 	raw                  bool
 	lastActivity         time.Time
@@ -1139,6 +1145,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		printer:            opts.Printer,
 		printsep:           opts.PrintSep,
 		proxyScript:        opts.ProxyScript,
+		setNativeLabel:     nativeLabelSetter(),
 		merger:             em,
 		passMerger:         em,
 		resultMerger:       em,
@@ -1248,13 +1255,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 	}
 
 	// Determine input border shape
-	if t.inputBorderShape == tui.BorderLine {
+	t.inputBorderShape = resolveInputBorderShape(t.layout, t.inputBorderShape)
-		if t.layout == layoutReverse {
-			t.inputBorderShape = tui.BorderBottom
-		} else {
-			t.inputBorderShape = tui.BorderTop
-		}
-	}
 
 	// Inline borders are embedded between the list's top and bottom horizontals.
 	// Shapes missing either one (none/phantom/line/single-sided) fall back to a plain
@@ -1299,14 +1300,16 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		}
 	}
 
-	// Disable separator by default if input border is set
+	// The default separator can be suppressed at runtime depending on the
-	if opts.Separator == nil && !t.inputBorderShape.Visible() || opts.Separator != nil && len(*opts.Separator) > 0 {
+	// window layout (see separatorLength)
-		bar := "─"
+	t.separatorAuto = opts.Separator == nil
-		if opts.Separator != nil {
+	bar := "─"
-			bar = *opts.Separator
+	if opts.Separator != nil {
-		} else if !t.unicode {
+		bar = *opts.Separator
-			bar = "-"
+	} else if !t.unicode {
-		}
+		bar = "-"
+	}
+	if len(bar) > 0 {
 		t.separator, t.separatorLen = t.ansiLabelPrinter(bar, &tui.ColSeparator, true)
 	}
 
@@ -1695,7 +1698,129 @@ func (t *Terminal) parsePrompt(prompt string) (func(), int) {
 }
 
 func (t *Terminal) noSeparatorLine() bool {
-	return t.inputless || noSeparatorLine(t.infoStyle, t.separatorLen > 0)
+	return t.inputless || noSeparatorLine(t.infoStyle, t.separatorLength() > 0)
+}
+
+// Effective length of the horizontal separator. The default separator is
+// suppressed when the input section is already visually separated from the
+// list section by a border line.
+func (t *Terminal) separatorLength() int {
+	if t.separatorAuto && t.separatedByBorder() {
+		return 0
+	}
+	return t.separatorLen
+}
+
+// BorderLine for the input border resolves to a single line on the side
+// facing the list section
+func resolveInputBorderShape(layout layoutType, shape tui.BorderShape) tui.BorderShape {
+	if shape != tui.BorderLine {
+		return shape
+	}
+	if layout == layoutReverse {
+		return tui.BorderBottom
+	}
+	return tui.BorderTop
+}
+
+// Whether the input border draws a line on the side facing the list section
+func inputBorderFacesList(layout layoutType, shape tui.BorderShape) bool {
+	shape = resolveInputBorderShape(layout, shape)
+	if layout == layoutReverse {
+		return shape.HasBottom()
+	}
+	return shape.HasTop()
+}
+
+// Whether a border line is already drawn between the info line and the
+// section next to it on the list side, making the default horizontal
+// separator redundant
+func (t *Terminal) separatedByBorder() bool {
+	// The input border itself draws a line on the side facing the list section
+	if inputBorderFacesList(t.layout, t.inputBorderShape) {
+		return true
+	}
+	// A preview window at 'next' position sits right next to the input
+	// section, in front of the sections handled below
+	anyNext := false
+	for po := &t.previewOpts; po != nil; po = po.alternative {
+		if po.position == posNext {
+			anyNext = true
+			break
+		}
+	}
+	if anyNext && t.hasPreviewer() {
+		// The separator is hidden only when every spec in the threshold chain
+		// displays a preview window at 'next' position with a border line
+		// facing the input section. We cannot single out the active spec;
+		// which one is active depends on the terminal size, and the
+		// resolution (computePreviewSize in resizeWindows) itself consults
+		// noSeparatorLine. When not every spec qualifies, err on the side of
+		// showing the separator.
+		if len(t.previewOpts.command) == 0 {
+			// No preview command, so no preview window is normally shown, but
+			// the preview(...) action can still display one at any time
+			return false
+		}
+		// NOTE: resizeWindows can clear 'hidden' mid-layout when the
+		// preview(...) action forces the window, so the frame being laid out
+		// can briefly disagree with this decision until the next relayout
+		for po := &t.previewOpts; po != nil; po = po.alternative {
+			if po.position != posNext || po.hidden || po.size.size == 0 || !t.borderFacingInput(po.Border(t.layout)) {
+				return false
+			}
+		}
+		return true
+	}
+	hasHeaderLinesWindow, headerLinesShape := t.determineHeaderLinesShape()
+	hasHeaderWindow := t.hasHeaderWindow()
+	// Mirror of hasInputWindow in resizeWindows; a 'next' preview position
+	// gives the input section its own window even when no preview window is
+	// shown. A 'next' spec here implies there is no previewer (the block
+	// above returns otherwise), and without a previewer the position is
+	// resolved from the first spec alone, so a 'next' in a threshold
+	// alternative does not count.
+	hasInputWindow := t.previewOpts.position == posNext || t.inputBorderShape.Visible() || hasHeaderWindow || hasHeaderLinesWindow
+	if !hasInputWindow {
+		// The input section is embedded in the list window and no border
+		// separates the two
+		return false
+	}
+
+	// The input section has its own window. Determine which section it is
+	// facing, and check if the border of that section draws a line toward it.
+	// NOTE: hasHeaderWindow can be true with no header content when the input
+	// border is visible (see Terminal.hasHeaderWindow). An empty header window
+	// takes no space, so it cannot be the facing section.
+	hasHeaderSection := hasHeaderWindow && t.visibleHeaderLines() > 0
+	if hasHeaderSection && !t.headerFirst && t.headerBorderShape != tui.BorderInline {
+		// Header section is facing the input section. An inline header is
+		// excluded; it is drawn inside the list border and is covered by the
+		// branches below.
+		return t.borderFacingInput(t.headerBorderShape)
+	}
+	// Header lines section is facing the input section, except in
+	// reverse-list layout where it is on the other side of the list section,
+	// or with --header-first and no header section where it is moved past
+	// the input section
+	if hasHeaderLinesWindow && t.layout != layoutReverseList && (hasHeaderWindow || !t.headerFirst) {
+		return t.borderFacingInput(headerLinesShape)
+	}
+	// The input section sits right next to the list section
+	return t.borderFacingInput(t.listBorderShape)
+}
+
+// Whether the border of the section next to the input section on the list
+// side draws a horizontal line facing the info line
+func (t *Terminal) borderFacingInput(shape tui.BorderShape) bool {
+	if shape == tui.BorderInline {
+		// Embedded between the horizontal lines of the list border
+		return true
+	}
+	if t.layout == layoutReverse {
+		return shape.HasTop()
+	}
+	return shape.HasBottom()
 }
 
 func getScrollbar(perLine int, total int, height int, offset int) (int, int) {
@@ -3330,6 +3455,7 @@ func (t *Terminal) printInfoImpl() {
 	}
 	pos := 0
 	line := 0
+	separatorLen := t.separatorLength()
 	maxHeight := t.window.Height()
 	move := func(y int, x int, clear bool) bool {
 		if y < 0 || y >= maxHeight {
@@ -3357,7 +3483,7 @@ func (t *Terminal) printInfoImpl() {
 			str = string(trimmed)
 			width = maxWidth
 		}
-		move(line, pos, t.separatorLen == 0)
+		move(line, pos, separatorLen == 0)
 		if t.reading {
 			t.window.CPrint(tui.ColSpinner, str)
 		} else {
@@ -3366,7 +3492,7 @@ func (t *Terminal) printInfoImpl() {
 		pos += width
 	}
 	printSeparator := func(fillLength int, pad bool) {
-		if t.separatorLen > 0 {
+		if separatorLen > 0 {
 			t.separator(t.window, fillLength)
 			t.window.Print(" ")
 		} else if pad {
@@ -3375,7 +3501,7 @@ func (t *Terminal) printInfoImpl() {
 	}
 
 	if t.infoStyle == infoHidden {
-		if t.separatorLen > 0 {
+		if separatorLen > 0 {
 			if !move(line+1, 0, false) {
 				return
 			}
@@ -3438,7 +3564,7 @@ func (t *Terminal) printInfoImpl() {
 	}
 	switch t.infoStyle {
 	case infoDefault:
-		if !move(line+1, 0, t.separatorLen == 0) {
+		if !move(line+1, 0, separatorLen == 0) {
 			return
 		}
 		printSpinner()
@@ -3522,7 +3648,7 @@ func (t *Terminal) printInfoImpl() {
 	}
 
 	if t.infoStyle == infoInlineRight {
-		if t.separatorLen > 0 {
+		if separatorLen > 0 {
 			if !move(line+1, 0, false) {
 				return
 			}
@@ -4553,15 +4679,23 @@ func (t *Terminal) renderPreviewArea(unchanged bool) {
 	height := t.pwindow.Height()
 	body := t.previewer.lines
 	headerLines := t.activePreviewOpts.headerLines
+	lineNo := -t.previewer.offset + headerLines
+	// Scrollbar is sized from the body alone, split off or not
+	scrollLines := len(body)
 	// Do not enable preview header lines if it's value is too large
 	if headerLines > 0 && headerLines < min(len(body), height) {
+		scrollLines -= headerLines
 		header := t.previewer.lines[0:headerLines]
-		body = t.previewer.lines[headerLines:]
+		// A separate header pass would resume the body inside an image, which
-		// Always redraw header
+		// takes up more rows than the line it arrives on
-		t.renderPreviewText(height, header, 0, false)
+		if !containsImage(header) {
-		t.pwindow.MoveAndClear(t.pwindow.Y(), 0)
+			// Always redraw header
+			t.renderPreviewText(height, header, 0, false)
+			t.pwindow.MoveAndClear(t.pwindow.Y(), 0)
+			body = t.previewer.lines[headerLines:]
+		}
 	}
-	t.renderPreviewText(height, body, -t.previewer.offset+headerLines, unchanged)
+	t.renderPreviewText(height, body, lineNo, unchanged)
 
 	if !unchanged {
 		t.pwindow.FinishFill()
@@ -4572,7 +4706,7 @@ func (t *Terminal) renderPreviewArea(unchanged bool) {
 	}
 
 	effectiveHeight := height - headerLines
-	barLength, barStart := getScrollbar(1, len(body), effectiveHeight, min(len(body)-effectiveHeight, t.previewer.offset-headerLines))
+	barLength, barStart := getScrollbar(1, scrollLines, effectiveHeight, min(scrollLines-effectiveHeight, t.previewer.offset-headerLines))
 	t.renderPreviewScrollbar(headerLines, barLength, barStart)
 }
 
@@ -4636,6 +4770,66 @@ func findPassThrough(line string) []int {
 	return []int{loc[0], loc[1] + pos + 2}
 }
 
+// tmux takes a bare APC as a request to set the pane title, so a Kitty
+// graphics command never reaches the terminal and clobbers the title on the
+// way. 'kitten icat --clear' emits one unwrapped. Sixel is left alone.
+// https://github.com/junegunn/fzf/issues/4870
+func wrapPassThrough(passThrough string, tmux bool) string {
+	if !tmux || !strings.HasPrefix(passThrough, "\x1b_G") {
+		return passThrough
+	}
+	// Only the sequence is passed through, not the trailing CR
+	suffix := ""
+	if strings.HasSuffix(passThrough, "\r") {
+		passThrough, suffix = passThrough[:len(passThrough)-1], "\r"
+	}
+	return "\x1bPtmux;" + strings.ReplaceAll(passThrough, "\x1b", "\x1b\x1b") + "\x1b\\" + suffix
+}
+
+// Whether the sequence draws an image. Kitty commands that only transmit or
+// delete do not
+func isImagePassThrough(passThrough string) bool {
+	// Unwrap the tmux passthrough sequence, in which every ESC is doubled
+	if after, ok := strings.CutPrefix(passThrough, "\x1bPtmux;"); ok {
+		passThrough = strings.ReplaceAll(after, "\x1b\x1b", "\x1b")
+	}
+	if after, ok := strings.CutPrefix(passThrough, "\x1b_G"); ok {
+		// Control data ends at the payload delimiter or at the terminator
+		keys := after
+		if index := strings.IndexAny(keys, ";\x1b"); index >= 0 {
+			keys = keys[:index]
+		}
+		for _, key := range strings.Split(keys, ",") {
+			// Transmit and display, or put an image already transmitted
+			if key == "a=T" || key == "a=p" {
+				return true
+			}
+		}
+		return false
+	}
+	if after, ok := strings.CutPrefix(passThrough, "\x1b]1337;"); ok {
+		return strings.HasPrefix(after, "File=") || strings.HasPrefix(after, "MultipartFile=")
+	}
+	return sixelBeginRegex.MatchString(passThrough)
+}
+
+// Whether any line carries an image
+func containsImage(lines []string) bool {
+	for _, line := range lines {
+		for {
+			loc := findPassThrough(line)
+			if loc == nil {
+				break
+			}
+			if isImagePassThrough(line[loc[0]:loc[1]]) {
+				return true
+			}
+			line = line[loc[1]:]
+		}
+	}
+	return false
+}
+
 func extractPassThroughs(line string) ([]string, string) {
 	passThroughs := []string{}
 	transformed := ""
@@ -4876,7 +5070,7 @@ Loop:
 				} else {
 					t.pwindow.Move(y, x)
 				}
-				t.tui.PassThrough(passThrough)
+				t.tui.PassThrough(wrapPassThrough(passThrough, inTmux))
 
 				if requiredLines > 0 {
 					if y+requiredLines == height {
@@ -6067,6 +6261,7 @@ func (t *Terminal) Loop() error {
 			for {
 				select {
 				case <-ctx.Done():
+					signal.Stop(intChan)
 					return
 				case s := <-intChan:
 					// Don't quit by SIGINT while executing because it should be for the executing command and not for fzf itself
@@ -6079,7 +6274,7 @@ func (t *Terminal) Loop() error {
 
 		if !t.tui.ShouldEmitResizeEvent() {
 			resizeChan := make(chan os.Signal, 1)
-			notifyOnResize(resizeChan) // Non-portable
+			notifyOnResize(ctx, resizeChan) // Non-portable
 			go func() {
 				for {
 					select {
@@ -7133,6 +7328,10 @@ func (t *Terminal) Loop() error {
 					if t.border != nil {
 						t.borderLabel, t.borderLabelLen = t.ansiLabelPrinter(label, &tui.ColBorderLabel, false)
 						req(reqRedrawBorderLabel)
+					} else if t.setNativeLabel != nil {
+						// fzf draws no border of its own; the label is on the
+						// native border of the floating pane
+						t.setNativeLabel(label)
 					}
 				})
 			case actChangePreviewLabel, actTransformPreviewLabel, actBgTransformPreviewLabel:
@@ -8157,6 +8356,8 @@ func (t *Terminal) Loop() error {
 			case actChangePreviewWindow:
 				// NOTE: We intentionally use "previewOpts" instead of "activePreviewOpts" here
 				currentPreviewOpts := t.previewOpts
+				wasNoSeparatorLine := t.noSeparatorLine()
+				wasSeparatorLength := t.separatorLength()
 
 				// Reset preview options and apply the additional options
 				t.previewOpts = t.initialPreviewOpts
@@ -8177,8 +8378,28 @@ func (t *Terminal) Loop() error {
 					a.a = strings.Join(append(tokens[1:], tokens[0]), "|")
 				}
 
+				// Do not drop a preview window forced by the preview(...) action
+				keepForcedPreview := t.hasPreviewWindow() && !t.activePreviewOpts.hidden
+
+				// The default separator is decided from the whole threshold
+				// chain (separatedByBorder), which compare does not fully
+				// inspect, so it can change even when compare finds no
+				// layout difference
+				checkSeparator := func() {
+					if t.noSeparatorLine() != wasNoSeparatorLine {
+						// Number of lines changed; relayout
+						updatePreviewWindow(keepForcedPreview)
+						req(reqPreviewRefresh)
+					} else if t.separatorLength() != wasSeparatorLength {
+						// Only the content of the info line changed
+						req(reqInfo)
+					}
+				}
+
 				// Full redraw
 				switch currentPreviewOpts.compare(t.activePreviewOpts, &t.previewOpts) {
+				case previewOptsSame:
+					checkSeparator()
 				case previewOptsDifferentLayout:
 					// Preview command can be running in the background if the size of
 					// the preview window is 0 but not 'hidden'
@@ -8186,7 +8407,7 @@ func (t *Terminal) Loop() error {
 
 					// FIXME: One-time preview window can't reappear once hidden
 					// fzf --bind space:preview:ls --bind 'enter:change-preview-window:down|left|up|hidden|'
-					updatePreviewWindow(t.hasPreviewWindow() && !t.activePreviewOpts.hidden)
+					updatePreviewWindow(keepForcedPreview)
 					if wasHidden && t.hasPreviewWindow() {
 						// Restart
 						refreshPreview(t.previewOpts.command)
@@ -8200,6 +8421,7 @@ func (t *Terminal) Loop() error {
 				case previewOptsDifferentContentLayout:
 					t.previewed.version = 0
 					req(reqPreviewRefresh)
+					checkSeparator()
 				}
 
 				// Adjust scroll offset

src/terminal_test.go

@@ -549,6 +549,89 @@ func TestExtractPassthroughs(t *testing.T) {
 	}
 }
 
+func TestWrapPassThrough(t *testing.T) {
+	for _, passThrough := range []string{
+		"\x1bPtmux;\x1b\x1b_Ga=d,d=A\x1b\x1b\\\x1b\\", // Already wrapped
+		"\x1bP0;1;0q#0;2;0;0;0#0~~@@vv@@~~@\x1b\\",    // Sixel
+		"\x1b]1337;File=inline=1:AAAA\a",              // iTerm2
+	} {
+		if got := wrapPassThrough(passThrough, true); got != passThrough {
+			t.Errorf("should have been left alone: %q -> %q", passThrough, got)
+		}
+	}
+
+	kitty := "\x1b_Ga=d,d=A\x1b\\"
+	if got := wrapPassThrough(kitty, false); got != kitty {
+		t.Errorf("should have been left alone outside of tmux: %q", got)
+	}
+
+	// ESC characters are doubled, and the trailing carriage return is kept
+	// outside of the wrapper
+	for _, test := range []struct{ input, want string }{
+		{kitty, "\x1bPtmux;\x1b\x1b_Ga=d,d=A\x1b\x1b\\\x1b\\"},
+		{kitty + "\r", "\x1bPtmux;\x1b\x1b_Ga=d,d=A\x1b\x1b\\\x1b\\\r"},
+		{"\x1b_Gm=1;\x1bAAA=\x1b\\", "\x1bPtmux;\x1b\x1b_Gm=1;\x1b\x1bAAA=\x1b\x1b\\\x1b\\"},
+	} {
+		if got := wrapPassThrough(test.input, true); got != test.want {
+			t.Errorf("expected %q, got %q", test.want, got)
+		}
+	}
+}
+
+func TestIsImagePassThrough(t *testing.T) {
+	for _, tc := range []struct {
+		given string
+		image bool
+	}{
+		// Kitty
+		{"\x1b_Ga=T,f=32,s=1258,v=1295,c=74,r=35,m=1\x1b\\", true},
+		{"\x1b_Ga=p,i=1\x1b\\", true},
+		// The action key is not always first, and a put carries no payload
+		{"\x1b_Gi=1,a=p\x1b\\", true},
+		{"\x1b_Ga=p\x1b\\", true},
+		{"\x1b_Ga=T,f=100\x1b\\\r", true},
+		{"\x1b_Gi=1,a=d\x1b\\", false},
+		{"\x1b_Ga=d,d=A\x1b\\", false},          // 'kitten icat --clear'
+		{"\x1b_Ga=q,i=1\x1b\\", false},          // query
+		{"\x1b_Gi=1,f=100\x1b\\", false},        // transmit only, the default action
+		{"\x1b_Gm=1;AAAA\x1b\\", false},         // continuation chunk
+		{"\x1b_Ga=f,i=1;AAAA\x1b\\", false},     // animation frame
+		{"\x1b_Ga=T,U=1,f=32;AAAA\x1b\\", true}, // unicode placeholder
+		// Wrapped in the tmux passthrough sequence
+		{"\x1bPtmux;\x1b\x1b_Ga=T,f=100\x1b\x1b\\\x1b\\", true},
+		{"\x1bPtmux;\x1b\x1b_Ga=d,d=A\x1b\x1b\\\x1b\\", false},
+		{"\x1bPtmux;\x1b\x1b_Gi=1,a=p\x1b\x1b\\\x1b\\", true},
+		// iTerm2
+		{"\x1b]1337;File=inline=1:AAAA\a", true},
+		{"\x1b]1337;MultipartFile=inline=1\a", true},
+		{"\x1b]1337;SetUserVar=foo=YmFy\a", false},
+		{"\x1b]1337;CurrentDir=/tmp\a", false},
+		// Sixel
+		{"\x1bP0;1;0q#0;2;0;0;0#0~~@@vv@@~~@\x1b\\", true},
+		{"\x1bPq#0~~\x1b\\", true},
+		{"\x1bPtmux;\x1b\x1bP0;1;0q#0~~\x1b\x1b\\\x1b\\", true},
+		{"", false},
+	} {
+		if actual := isImagePassThrough(tc.given); actual != tc.image {
+			t.Errorf("expected %v for %q, got %v", tc.image, tc.given, actual)
+		}
+	}
+
+	if containsImage([]string{"foo", "bar"}) {
+		t.Error("plain text carries no image")
+	}
+	if !containsImage([]string{"foo", "bar\x1b_Ga=T,f=100\x1b\\baz"}) {
+		t.Error("failed to find an image in a line")
+	}
+	if containsImage([]string{"foo\x1b_Ga=d,d=A\x1b\\"}) {
+		t.Error("a delete command is not an image")
+	}
+	// The image is not the first passthrough on the line
+	if !containsImage([]string{"\x1b_Ga=d,d=A\x1b\\text\x1b_Ga=T,f=100;AAAA\x1b\\"}) {
+		t.Error("failed to look past an earlier passthrough")
+	}
+}
+
 /* utilities section */
 
 // Item represents one line in fzf UI. Usually it is relative path to files and folders.

src/terminal_unix.go

@@ -3,6 +3,7 @@
 package fzf
 
 import (
+	"context"
 	"os"
 	"os/signal"
 	"syscall"
@@ -10,8 +11,12 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-func notifyOnResize(resizeChan chan<- os.Signal) {
+func notifyOnResize(ctx context.Context, resizeChan chan<- os.Signal) {
 	signal.Notify(resizeChan, syscall.SIGWINCH)
+	go func() {
+		<-ctx.Done()
+		signal.Stop(resizeChan)
+	}()
 }
 
 func notifyStop(p *os.Process) {

src/terminal_windows.go

@@ -3,11 +3,58 @@
 package fzf
 
 import (
+	"context"
 	"os"
+	"syscall"
+	"time"
+
+	"golang.org/x/sys/windows"
 )
 
-func notifyOnResize(resizeChan chan<- os.Signal) {
+const resizePollInterval = 100 * time.Millisecond
-	// TODO
+
+type resizeSignal struct{}
+
+func (resizeSignal) String() string { return "resize" }
+func (resizeSignal) Signal()        {}
+
+// Windows has no SIGWINCH, so poll the console screen buffer for window
+// size changes instead.
+func notifyOnResize(ctx context.Context, resizeChan chan<- os.Signal) {
+	consoleOut, err := syscall.Open("CONOUT$", syscall.O_RDWR, 0)
+	if err != nil {
+		return
+	}
+	var info windows.ConsoleScreenBufferInfo
+	if windows.GetConsoleScreenBufferInfo(windows.Handle(consoleOut), &info) != nil {
+		syscall.Close(consoleOut)
+		return
+	}
+	last := info.Window
+	go func() {
+		defer syscall.Close(consoleOut)
+		ticker := time.NewTicker(resizePollInterval)
+		defer ticker.Stop()
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case <-ticker.C:
+			}
+			if windows.GetConsoleScreenBufferInfo(windows.Handle(consoleOut), &info) != nil {
+				continue
+			}
+			current := info.Window
+			if current.Right-current.Left != last.Right-last.Left ||
+				current.Bottom-current.Top != last.Bottom-last.Top {
+				last = current
+				select {
+				case resizeChan <- resizeSignal{}:
+				default:
+				}
+			}
+		}
+	}()
 }
 
 func notifyStop(p *os.Process) {

src/tmux.go

@@ -46,21 +46,35 @@ func tmuxFloatingPaneInfo() (int, int, bool) {
 	return width, height, true
 }
 
-// A lone ';' argument is a command separator to tmux, aborting the whole
+// tmux ends a command at an argument ending in ';', so a trailing one is
-// command at parse time
+// escaped. Elsewhere it is not special
 func escapeTmuxSeparator(str string) string {
-	if str == ";" {
+	if strings.HasSuffix(str, ";") {
-		return `\;`
+		return str[:len(str)-1] + `\;`
 	}
 	return str
 }
 
-// Escape a string for use as the pane title; select-pane -T expands format
+// '#[...]' is still processed when a substituted value is drawn, so '#' is
-// expressions denoted by '#', but not time conversion specifiers
+// doubled. '#{...}' is already literal
-func escapeTmuxTitle(str string) string {
+func escapeTmuxFormat(str string) string {
 	return escapeTmuxSeparator(strings.ReplaceAll(str, "#", "##"))
 }
 
+// The option pane-border-format reads back, and the pane it is set on
+const (
+	tmuxBorderLabelOption = "@fzf-border-label"
+	tmuxBorderLabelEnv    = internalEnvPrefix + "TMUX_LABEL_PANE"
+)
+
+// Errors are ignored. The pane may be gone
+func setTmuxBorderLabel(pane string, label string) {
+	// Strip ANSI sequences. tmux would draw the escape's remainder as text
+	label, _, _ = extractColor(label, nil, nil)
+	exec.Command("tmux", "set-option", "-p", "-t", pane,
+		tmuxBorderLabelOption, escapeTmuxFormat(label)).Run()
+}
+
 // Convert sizeSpec to the number of cells, clamped between the minimum
 // footprint of 3, including the border, and the window size
 func tmuxDim(spec sizeSpec, window int) int {
@@ -128,35 +142,28 @@ func runTmuxFloatingPane(argStr string, dir string, windowWidth int, windowHeigh
 		// remain-on-exit is on.
 		setup := `tmux set-option -p -t "$TMUX_PANE" remain-on-exit off 2> /dev/null; `
 
-		// Set --border-label as the title of the floating pane, and as its
+		// --border-label lives in a pane-scoped user option that
-		// pane-border-format so that it is displayed on the border when
+		// pane-border-format reads back, so a program in the pane cannot
-		// pane-border-status is enabled. Without a label, the border text
+		// replace it by setting the title. Set even when empty, so
-		// is cleared so that the default pane status content (e.g. the
+		// change-border-label can fill it in and the default pane status is
-		// pane title) is not shown. pane-border-format is pane-scoped,
+		// not shown. pane-border-status is a window option until the next
-		// but pane-border-status is a window option that only becomes
+		// tmux release, so it is left alone.
-		// pane-scoped in the next release of tmux, so it is left alone.
 		//   https://github.com/tmux/tmux/commit/7a18fa281db3
-		// --border-label-pos is ignored.
+		// --border-label-pos is ignored. With an explicit --border fzf draws
-		// The label is left to fzf when it draws its own border with the
+		// the label itself, but the native border cannot be removed.
-		// label on it. '--border=none' is not the case; fzf would not
+		ownsLabel := noBorderSpecified(opts)
-		// display the label, but the native border of a floating pane
+		label := ""
-		// cannot be removed, so display the label on it nonetheless.
+		if ownsLabel {
-		format := ""
-		if opts.BorderLabel.label != "" &&
-			(opts.BorderShape == tui.BorderUndefined || opts.BorderShape == tui.BorderLine ||
-				opts.BorderShape == tui.BorderNone) {
 			// Strip ANSI sequences fzf would otherwise render itself
-			label, _, _ := extractColor(opts.BorderLabel.label, nil, nil)
+			label, _, _ = extractColor(opts.BorderLabel.label, nil, nil)
-			if label != "" {
-				setup += fmt.Sprintf(`tmux select-pane -t "$TMUX_PANE" -T %s 2> /dev/null; `,
-					escapeSingleQuote(escapeTmuxTitle(label)))
-				// The title is displayed verbatim; substituted values are
-				// not expanded again
-				format = "#{pane_title}"
-			}
 		}
+		setup += fmt.Sprintf(`tmux set-option -p -t "$TMUX_PANE" %s %s 2> /dev/null; `,
+			tmuxBorderLabelOption, escapeSingleQuote(escapeTmuxFormat(label)))
 		setup += fmt.Sprintf(`tmux set-option -p -t "$TMUX_PANE" pane-border-format %s 2> /dev/null; `,
-			escapeSingleQuote(format))
+			escapeSingleQuote("#{"+tmuxBorderLabelOption+"}"))
+		if ownsLabel {
+			setup += fmt.Sprintf(`export %s="$TMUX_PANE"; `, tmuxBorderLabelEnv)
+		}
 		paneCmd := fmt.Sprintf("%s%s %s; echo $? > %s; tmux wait-for -S %s",
 			setup, escapeSingleQuote(sh), escapeSingleQuote(temp), code, signal)
 		// Unzoom the window first; creating a floating pane over a zoomed
@@ -193,16 +200,20 @@ exit "$code"`, newPane, code, signal, signal, code, code, code)
 	}, opts, true)
 }
 
+// Whether no box border was asked for. 'none' and 'line' count as none.
+// fzf draws no box for either
+func noBorderSpecified(opts *Options) bool {
+	return opts.BorderShape == tui.BorderUndefined ||
+		opts.BorderShape == tui.BorderLine || opts.BorderShape == tui.BorderNone
+}
+
 // Whether to use the multiplexer's native border for the floating pane. Its
 // native border is the handle that makes the pane movable and resizable with
 // the mouse, so it is the default; 'border-native' forces it. It is not used
 // when a border style is explicitly specified with --border, so that the
-// fzf-drawn border is the only one shown. 'none' and 'line' are treated as no
+// fzf-drawn border is the only one shown.
-// border; fzf draws no box for either, and 'line' only makes sense with
-// --height.
 func nativeBorder(opts *Options) bool {
-	return opts.Tmux.border || opts.BorderShape == tui.BorderUndefined ||
+	return opts.Tmux.border || noBorderSpecified(opts)
-		opts.BorderShape == tui.BorderLine || opts.BorderShape == tui.BorderNone
 }
 
 func runTmux(args []string, opts *Options) (int, error) {

src/tmux_test.go

@@ -2,37 +2,51 @@ package fzf
 
 import "testing"
 
-func TestEscapeTmuxTitle(t *testing.T) {
+func TestEscapeTmuxFormat(t *testing.T) {
 	for _, tc := range []struct {
 		given    string
 		expected string
 	}{
 		{"", ""},
 		{" fzf ", " fzf "},
-		{"#", "##"},
-		{"##", "####"},
-		{" C# notes #S ", " C## notes ##S "},
 		{"100%", "100%"},
+		// '#[' would be taken as a style directive when the label is drawn
+		{"#[fg=red]x", "##[fg=red]x"},
+		// '#{' is already literal in a substituted value, but doubling it
+		// keeps a label that fzf renders itself looking the same
+		{"#{pane_id}", "##{pane_id}"},
+		{" C# notes #S ", " C## notes ##S "},
 		{";", `\;`},
 		{"; rm", "; rm"},
-		{" ; ", " ; "},
+		{"C#;", `C##\;`},
 	} {
-		if actual := escapeTmuxTitle(tc.given); actual != tc.expected {
+		if actual := escapeTmuxFormat(tc.given); actual != tc.expected {
 			t.Errorf("expected %q, got %q", tc.expected, actual)
 		}
 	}
 }
 
-func TestEscapeTmuxTitleSeparator(t *testing.T) {
+func TestEscapeTmuxSeparator(t *testing.T) {
 	for _, tc := range []struct {
 		given    string
 		expected string
 	}{
-		{"#;", "##;"},
+		{"", ""},
-		{";#", ";##"},
+		{" fzf ", " fzf "},
-		{";;", ";;"},
+		{"#", "#"},
+		{"#{pane_id}", "#{pane_id}"},
+		{"100%", "100%"},
+		// tmux drops a trailing ';' and everything after it, so only that
+		// one is escaped
+		{";", `\;`},
+		{"abc;", `abc\;`},
+		{";;", `;\;`},
+		{`foo\;`, `foo\\;`},
+		{"; rm", "; rm"},
+		{" ; ", " ; "},
+		{"a;b", "a;b"},
 	} {
-		if actual := escapeTmuxTitle(tc.given); actual != tc.expected {
+		if actual := escapeTmuxSeparator(tc.given); actual != tc.expected {
 			t.Errorf("expected %q, got %q", tc.expected, actual)
 		}
 	}

src/zellij.go

@@ -1,11 +1,20 @@
 package fzf
 
 import (
+	"fmt"
 	"os/exec"
-
-	"github.com/junegunn/fzf/src/tui"
 )
 
+const zellijBorderLabelEnv = internalEnvPrefix + "ZELLIJ_LABEL_PANE"
+
+// Errors are ignored. The pane may be gone
+func setZellijBorderLabel(pane string, label string) {
+	// Strip ANSI sequences fzf would otherwise render itself
+	label, _, _ = extractColor(label, nil, nil)
+	// '--' so that a label starting with a hyphen is not parsed as a flag
+	exec.Command("zellij", "action", "rename-pane", "-p", pane, "--", label).Run()
+}
+
 func runZellij(args []string, opts *Options) (int, error) {
 	// Use the native Zellij border by default, consistent with tmux, so that
 	// the pane can be moved and resized with the mouse. Set before
@@ -20,6 +29,7 @@ func runZellij(args []string, opts *Options) (int, error) {
 		"run", "--floating", "--close-on-exit", "--block-until-exit",
 		"--cwd", dir,
 	}
+	ownsLabel := false
 	if !opts.Tmux.border {
 		zellijArgs = append(zellijArgs, "--borderless", "true")
 	} else {
@@ -33,8 +43,8 @@ func runZellij(args []string, opts *Options) (int, error) {
 		// stripping ANSI sequences fzf would otherwise render itself.
 		// --border-label-pos is ignored.
 		label := ""
-		if opts.BorderShape == tui.BorderUndefined || opts.BorderShape == tui.BorderLine ||
+		ownsLabel = noBorderSpecified(opts)
-			opts.BorderShape == tui.BorderNone {
+		if ownsLabel {
 			label, _, _ = extractColor(opts.BorderLabel.label, nil, nil)
 		}
 		zellijArgs = append(zellijArgs, "--name="+label)
@@ -60,7 +70,14 @@ func runZellij(args []string, opts *Options) (int, error) {
 		if err != nil {
 			return nil, err
 		}
-		zellijArgs = append(zellijArgs, sh, temp)
+		if ownsLabel {
+			// 'zellij run' cannot set the new pane's environment, so the
+			// command exports it itself. exec avoids a lingering shell
+			zellijArgs = append(zellijArgs, sh, "-c", fmt.Sprintf(`export %s="$ZELLIJ_PANE_ID"; exec %s %s`,
+				zellijBorderLabelEnv, escapeSingleQuote(sh), escapeSingleQuote(temp)))
+		} else {
+			zellijArgs = append(zellijArgs, sh, temp)
+		}
 		return exec.Command("zellij", zellijArgs...), nil
 	}, opts, true)
 }

test/test_layout.rb

@@ -248,7 +248,7 @@ class TestLayout < TestInteractive
     tmux.send_keys %(seq 5 | #{FZF} --layout=reverse --preview 'echo PREVIEW' --preview-window=next:3 --prompt='line2$ > '), :Enter
     expected = <<~OUTPUT
       line2$ >
-        5/5 ───
+        5/5
       ╭────────
       │ PREVIEW
       │
@@ -268,7 +268,7 @@ class TestLayout < TestInteractive
       │
       │
       ╰────────
-        5/5 ───
+        5/5
       >
     OUTPUT
     tmux.until { assert_block(expected, it) }
@@ -597,7 +597,7 @@ class TestLayout < TestInteractive
       │   │ 2
       │   │ 1
       │   └header──
-      │     19/97 ─
+      │     19/97
       │   > 1
       │
       ╰────────────
@@ -628,7 +628,7 @@ class TestLayout < TestInteractive
       ╭────────────
       │   hello
       ╰────────────
-          100/100 ─
+          100/100
         >
     BLOCK
     tmux.until { assert_block(block2, it) }
@@ -648,7 +648,7 @@ class TestLayout < TestInteractive
       │   2
       │   1
       ╰──────────
-          98/98 ─
+          98/98
         >
     BLOCK
     tmux.until { assert_block(block1, it) }
@@ -663,7 +663,7 @@ class TestLayout < TestInteractive
       │   1
       │   hello
       ╰──────────
-          98/98 ─
+          98/98
         >
     BLOCK
     tmux.until { assert_block(block2, it) }
@@ -679,7 +679,7 @@ class TestLayout < TestInteractive
       │   4
       │ > 3
       ╰──────────
-          98/98 ─
+          98/98
         >
       ╭──────────
       │   2
@@ -718,7 +718,7 @@ class TestLayout < TestInteractive
       ║   2
       ║   1
       ╚══════════
-          98/98 ─
+          98/98
         >
     BLOCK
     tmux.until { assert_block(block1, it) }
@@ -734,7 +734,7 @@ class TestLayout < TestInteractive
       ╭──────────
       │   hello
       ╰──────────
-          98/98 ─
+          98/98
         >
     BLOCK
     tmux.until { assert_block(block2, it) }
@@ -750,7 +750,7 @@ class TestLayout < TestInteractive
       │   4
       │ > 3
       ╰──────────
-          98/98 ─
+          98/98
         >
       ╔══════════
       ║   2
@@ -767,7 +767,7 @@ class TestLayout < TestInteractive
       ║   2
       ║   1
       ╚══════════
-          98/98 ─
+          98/98
         >
       ╭──────────
       │   hello
@@ -810,7 +810,7 @@ class TestLayout < TestInteractive
       │   │   2
       │   │   1
       │   └header────
-      │       19/97 ─
+      │       19/97
       │     > 1
       │
       ╰──────────────
@@ -825,7 +825,7 @@ class TestLayout < TestInteractive
       │   ║   11
       │   ║ > 10
       │   ╚list══════
-      │       19/97 ─
+      │       19/97
       │     > 1
       │   ┌──────────
       │   │   3
@@ -1039,9 +1039,9 @@ class TestLayout < TestInteractive
       └──────── │   103   │   101   │   103   │   101   │ │ 102   │ ┌────── │ │ 102   │ ┌────── │   2/2 ─ │ ┌─────── │ ┌───── │   103    │ ┌─────── │ ┌───────
                 │   5/5 ─ │   102   │   2/2 ─ │   102   │ │ 103   │ │ 101   │ │ 103   │ │ 101   │ >       │ │   2/2  │ │ 101  │ ┌─────── │ │   101  │ │ >
                 │ >       │   103   │ >       │   103   │ └────── │ │ 102   │ └────── │ │ 102   │ ┌────── │ │ >      │ │ 102  │ │   5/5  │ │   102  │ └───────
-                └──────── └──────── └──────── └──────── │   5/5 ─ │ │ 103   │   2/2 ─ │ │ 103   │ │ 101   │ └─────── │ │ 103  │ │ >      │ │   103  │ ┌───────
+                └──────── └──────── └──────── └──────── │   5/5   │ │ 103   │   2/2   │ │ 103   │ │ 101   │ └─────── │ │ 103  │ │ >      │ │   103  │ ┌───────
                                                         │ >       │ └────── │ >       │ └────── │ │ 102   │ ┌─────── │ └───── │ └─────── │ └─────── │ │   101
-                                                        └──────── └──────── └──────── │   2/2 ─ │ │ 103   │ │ 101    └─────── └───────── │ ┌─────── │ │   102
+                                                        └──────── └──────── └──────── │   2/2   │ │ 103   │ │ 101    └─────── └───────── │ ┌─────── │ │   102
                                                                                       │ >       │ └────── │ │ 102                        │ │ >      │ │   103
                                                                                       └──────── └──────── │ │ 103                        │ └─────── │ └───────
                                                                                                           │ └───────                     └───────── └─────────
@@ -1099,9 +1099,9 @@ class TestLayout < TestInteractive
       │ >       │   102   │ >       │   102   │ >       │ │ 101   │ >       │ │ 101   │ │ 101   │ │ 101   │ └────── │ └─────── │ └────── │   101   │ │ > 1
       └──────── │   3/3 ─ │   101   │   1/1 ─ │   101   │ │ 102   │ ┌────── │ │ 102   │ │ 102   │ │ 102   │ ┌────── │ ┌─────── │ ┌────── │   102   │ └───────
                 │ >       │   102   │ >       │   102   │ └─HEAD─ │ │ 101   │ └─HEAD─ │ └─HEAD─ │ └─HEAD─ │ │ 101   │ │   1/1  │ │ 101   │ ─────── │ ┌───────
-                └──────── └──────── └──────── └──────── │   3/3 ─ │ │ 102   │   1/1 ─ │   1/1 ─ │   1/1 ─ │ │ 102   │ │ >      │ │ 102   │   3/3   │ │ >
+                └──────── └──────── └──────── └──────── │   3/3   │ │ 102   │   1/1   │   1/1   │   1/1   │ │ 102   │ │ >      │ │ 102   │   3/3   │ │ >
                                                         │ >       │ └─HEAD─ │ >       │ >       │ >       │ └─HEAD─ │ └─────── │ └─HEAD─ │ >       │ └───────
-                                                        └──────── └──────── └──────── └──────── └──────── │   1/1 ─ │ ┌─────── └──────── └──────── │ ┌───────
+                                                        └──────── └──────── └──────── └──────── └──────── │   1/1   │ ┌─────── └──────── └──────── │ ┌───────
                                                                                                           │ >       │ │ 101                        │ │   101
                                                                                                           └──────── │ │ 102                        │ │   102
                                                                                                                     │ └─HEAD──                     │ └─HEAD──
@@ -1159,9 +1159,9 @@ class TestLayout < TestInteractive
       │ >       │   102   │ >       │   102   │ >       │ │ 101   │ >       │ │ 101   │ > 3     │ > 3      │ > 3     │   101   │ │   3
       └──────── │   3/3 ─ │   101   │   1/1 ─ │   101   │ │ 102   │ ┌────── │ │ 102   │ ┌────── │ ┌─────── │ ┌────── │   102   │ └───────
                 │ >       │   102   │ >       │   102   │ └─HEAD─ │ │ 101   │ └─HEAD─ │ │ 101   │ │   1/1  │ │ 101   │ ─────── │ ┌───────
-                └──────── └──────── └──────── └──────── │   3/3 ─ │ │ 102   │   1/1 ─ │ │ 102   │ │ >      │ │ 102   │   3/3   │ │ >
+                └──────── └──────── └──────── └──────── │   3/3   │ │ 102   │   1/1   │ │ 102   │ │ >      │ │ 102   │   3/3   │ │ >
                                                         │ >       │ └─HEAD─ │ >       │ └─HEAD─ │ └─────── │ └─HEAD─ │ >       │ └───────
-                                                        └──────── └──────── └──────── │   1/1 ─ │ ┌─────── └──────── └──────── │ ┌───────
+                                                        └──────── └──────── └──────── │   1/1   │ ┌─────── └──────── └──────── │ ┌───────
                                                                                       │ >       │ │ 101                        │ │   101
                                                                                       └──────── │ │ 102                        │ │   102
                                                                                                 │ └─HEAD──                     │ └─HEAD──
@@ -1191,7 +1191,7 @@ class TestLayout < TestInteractive
       │ ┌─label──
       │ │ header
       │ └────────
-      │   10/10 ─
+      │   10/10
       │ >
       └──────────
     BLOCK
@@ -1228,13 +1228,282 @@ class TestLayout < TestInteractive
     end
   end
 
+  def test_separator_with_input_border
+    # Border line below input does not face the list; separator is shown
+    tmux.send_keys %(seq 100 | #{FZF} --input-border bottom), :Enter
+    block = <<~BLOCK
+      > 1
+        100/100 ──
+      >
+      ────────────
+    BLOCK
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # List border faces the input instead; separator is hidden
+    tmux.send_keys %(seq 100 | #{FZF} --input-border bottom --list-border rounded), :Enter
+    block = <<~BLOCK
+      │ > 1
+      ╰────────────
+          100/100
+        >
+      ─────────────
+    BLOCK
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # Border line above input faces the list; separator is hidden
+    tmux.send_keys %(seq 100 | #{FZF} --input-border top), :Enter
+    block = <<~BLOCK
+      > 1
+      ────────────
+        100/100
+      >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+  end
+
+  def test_separator_with_input_border_reverse
+    # Border line above input does not face the list; separator is shown
+    tmux.send_keys %(seq 100 | #{FZF} --layout reverse --input-border top), :Enter
+    block = <<~BLOCK
+      ────────────
+      >
+        100/100 ──
+      > 1
+    BLOCK
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # Border line below input faces the list; separator is hidden
+    tmux.send_keys %(seq 100 | #{FZF} --layout reverse --input-border bottom), :Enter
+    block = <<~BLOCK
+      >
+        100/100
+      ────────────
+      > 1
+    BLOCK
+    tmux.until { assert_block(block, it) }
+  end
+
+  def test_separator_with_preview_next
+    # Preview window at 'next' position sits next to the input section, so the
+    # header border does not hide the separator
+    tmux.send_keys %(seq 100 | #{FZF} --header foo --header-border rounded --no-list-border --preview 'echo hi' --preview-window next,1,border-none), :Enter
+    block = <<~BLOCK
+      ╰────────────
+      hi
+        100/100 ───
+      >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # Same when 'next' position comes from a threshold alternative
+    tmux.send_keys %(seq 100 | #{FZF} --header foo --header-border rounded --no-list-border --preview 'echo hi' --preview-window 'up,40%,<9999(next,1,border-none)'), :Enter
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # A border of the preview window at 'next' position facing the input
+    # section hides the separator
+    tmux.send_keys %(seq 100 | #{FZF} --preview : --preview-window next,3), :Enter
+    block = <<~BLOCK
+      ╰────────────
+        100/100
+      >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # Same when every spec in the threshold chain is a bordered preview
+    # window at 'next' position
+    tmux.send_keys %(seq 100 | #{FZF} --preview : --preview-window 'next,3,<15(next,3)'), :Enter
+    tmux.until { assert_block(block, it) }
+  end
+
+  def test_separator_with_preview_next_toggle
+    tmux.send_keys %(seq 100 | #{FZF} --preview 'echo hi' --preview-window next,3,hidden --bind space:toggle-preview), :Enter
+    hidden = <<~BLOCK
+      > 1
+        100/100 ──
+      >
+    BLOCK
+    tmux.until { assert_block(hidden, it) }
+
+    tmux.send_keys :Space
+    shown = <<~BLOCK
+      │ hi
+      │
+      │
+      ╰────────────
+        100/100
+      >
+    BLOCK
+    tmux.until { assert_block(shown, it) }
+
+    tmux.send_keys :Space
+    tmux.until { assert_block(hidden, it) }
+  end
+
+  def test_separator_with_preview_next_alternative_only
+    # 'next' appears only in a threshold alternative and there is no
+    # previewer, so the input section stays embedded in the list window and
+    # needs the separator
+    tmux.send_keys %(seq 100 | #{FZF} --preview-window '<9999(next)' --list-border rounded), :Enter
+    block = <<~BLOCK
+      │ > 1
+      │   100/100 ──
+      │ >
+      ╰─────────────
+    BLOCK
+    tmux.until { assert_block(block, it) }
+  end
+
+  def test_separator_with_preview_action_at_next
+    # preview(...) action can display an ad-hoc preview window at 'next'
+    # position at any time; the list border must not hide the separator
+    tmux.send_keys %(seq 100 | #{FZF} --list-border rounded --preview-window 'next,border-left,5' --bind 'space:preview(echo hi)'), :Enter
+    block = <<~BLOCK
+      ╰─────────────
+          100/100 ──
+        >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+
+    tmux.send_keys :Space
+    block = <<~BLOCK
+      │ hi
+      │
+      │
+      │
+      │
+          100/100 ──
+        >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+  end
+
+  def test_separator_change_preview_window_keeps_forced_preview
+    # Relayout triggered by the separator visibility change must not drop a
+    # preview window opened via the preview(...) action
+    tmux.send_keys %(seq 100 | #{FZF} --info hidden --input-border left --list-border --preview-window 'up,50%,<5(next)' --bind 'space:preview(echo AD-HOC)' --bind 'x:change-preview-window(up,50%,<5(up))'), :Enter
+    tmux.until { |lines| assert_includes lines.join, '│ ─' }
+
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert_includes lines.join, 'AD-HOC'
+      assert_includes lines.join, '│ ─'
+    end
+
+    # Only the inactive threshold alternative changes; separator is hidden
+    # by the list border, and the forced preview window must survive
+    tmux.send_keys :x
+    tmux.until do |lines|
+      assert_includes lines.join, 'AD-HOC'
+      refute_includes lines.join, '│ ─'
+    end
+  end
+
+  def test_separator_with_change_preview_window_chain
+    # change-preview-window that only alters a non-active spec must still
+    # trigger a relayout when it changes the separator visibility
+    tmux.send_keys %(seq 100 | #{FZF} --info hidden --layout reverse --preview 'echo hi' --preview-window 'next,3,border-none,<100(next,3,border-top)' --bind 'space:change-preview-window(next,3,border-top,<100(next,3,border-top))'), :Enter
+    block = <<~BLOCK
+      >
+      ──────────
+      ──────────
+      hi
+    BLOCK
+    tmux.until { assert_block(block, it) }
+
+    tmux.send_keys :Space
+    block = <<~BLOCK
+      >
+      ──────────
+      hi
+    BLOCK
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # Also when only the drawn bar changes; the info line row count is
+    # constant with the default info style
+    tmux.send_keys %(seq 100 | #{FZF} --layout reverse --preview 'echo hi' --preview-window 'next,3,border-none,<100(next,3,border-top)' --bind 'space:change-preview-window(next,3,border-top,<100(next,3,border-top))'), :Enter
+    block = <<~BLOCK
+      >
+        100/100 ──
+    BLOCK
+    tmux.until { assert_block(block, it) }
+
+    tmux.send_keys :Space
+    block = <<~BLOCK
+      >
+        100/100
+      ────────────
+    BLOCK
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # Also when compare finds a content-layout difference (scroll offset)
+    tmux.send_keys %(seq 100 | #{FZF} --info hidden --preview 'echo hi' --preview-window 'next,3,<2(up,3)' --bind 'space:change-preview-window(next,3,+1,<2(next,3))'), :Enter
+    block = <<~BLOCK
+      ╰────────────
+      ─────────────
+      >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+
+    tmux.send_keys :Space
+    block = <<~BLOCK
+      ╰────────────
+      >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+  end
+
+  def test_separator_with_inline_header_border
+    # Inline header is drawn inside the list border; bare header lines sit
+    # next to the input section, so the separator is shown
+    tmux.send_keys %(seq 100 | #{FZF} --list-border rounded --header foo --header-lines 2 --header-border inline --header-lines-border none), :Enter
+    block = <<~BLOCK
+      ╰────────────
+          2
+          1
+          98/98 ───
+        >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+    teardown
+    setup
+
+    # Header lines are embedded in the list border along with the inline
+    # header; the list border faces the input section and hides the separator
+    tmux.send_keys %(seq 100 | #{FZF} --list-border rounded --header foo --header-lines 2 --header-border inline), :Enter
+    block = <<~BLOCK
+      │   2
+      │   1
+      │   foo
+      ╰────────────
+          98/98
+        >
+    BLOCK
+    tmux.until { assert_block(block, it) }
+  end
+
   def test_header_border_no_pointer_and_marker
     tmux.send_keys %(seq 10 | #{FZF} --header-lines 1 --header-border sharp --no-list-border --pointer '' --marker ''), :Enter
     block = <<~BLOCK
       ┌──────
       │ 1
       └──────
-        9/9 ─
+        9/9
       >
     BLOCK
     tmux.until { assert_block(block, it) }

test/test_shell_integration.rb

@@ -965,6 +965,18 @@ class TestZsh < TestBase
     end
   end
 
+  # Duplicate 'chpwd' calls overcount visits => skews rank tracking tools (e.g. 'zoxide')
+  def test_alt_c_chpwd_hook_once
+    tmux.send_keys "chpwd() { echo 'chpwd hook fired' >&2 }", :Enter
+    tmux.prepare
+    tmux.send_keys :Escape, :c
+    tmux.until { |lines| assert_operator lines.match_count, :>, 0 }
+    tmux.send_keys :Enter
+    tmux.until do |lines|
+      assert_equal 1, lines.count { |l| l.include?('chpwd hook fired') }
+    end
+  end
+
   # Helper function to run test with Perl and again with Awk
   def self.test_perl_and_awk(name, &block)
     define_method(:"test_#{name}") do
@@ -999,6 +1011,20 @@ class TestZsh < TestBase
     tmux.send_keys 'C-l', 'C-r'
   end
 
+  test_perl_and_awk 'ctrl_r_exit_code' do
+    exit_file = "#{tempname}-exit"
+    # Wrapper captures status, as widgets return values don't propagate to "$?"
+    # A non-zero status causes the shell to beep when the widget exits (man zshzle)
+    tmux.send_keys %(f() { zle fzf-history-widget; echo $? > #{exit_file}; zle reset-prompt } && zle -N f && bindkey "^R" f), :Enter
+    prepare_ctrl_r_test
+    tmux.until { |lines| assert_operator lines.match_count, :>, 0 }
+    tmux.send_keys 'C-g' # abort
+    tmux.send_keys "cat #{exit_file}", :Enter
+    tmux.until { |lines| assert_equal '130', lines[-1] }
+  ensure
+    FileUtils.rm_f(exit_file)
+  end
+
   test_perl_and_awk 'ctrl_r_accept_or_print_query' do
     set_var('FZF_CTRL_R_OPTS', '--bind enter:accept-or-print-query')
     prepare_ctrl_r_test

test/test_tmux.rb

@@ -17,9 +17,11 @@ class TestTmux < TestInteractive
   def test_floating_pane
     tmux.send_keys "seq 100 | #{fzf('--popup center,80% --margin 0')}", :Enter
     tmux.until { |lines| assert_equal 100, lines.item_count }
-    # Border text is cleared when no label is given
+    # Border text is empty when no label is given
-    format = IO.popen(['tmux', 'show-options', '-p', '-t', floating_pane, 'pane-border-format'], &:read)
+    pane = floating_pane
-    assert_includes format, "''"
+    refute_nil pane
+    assert_equal "\#{@fzf-border-label}", pane_option(pane, 'pane-border-format')
+    assert_equal '', pane_option(pane, '@fzf-border-label')
     tmux.send_keys '99'
     tmux.until { |lines| assert_equal 1, lines.match_count }
     tmux.send_keys :Enter
@@ -40,10 +42,41 @@ class TestTmux < TestInteractive
     tmux.until { |lines| assert_equal 100, lines.item_count }
     pane = floating_pane
     refute_nil pane
+    # The label is held in a user option, not in the pane title, which is
+    # left to the user. '#' is doubled so that the label is drawn as it is
+    # written, instead of '#[...]' being taken as a style directive
+    assert_equal ' ##fzf-label 100% ', pane_option(pane, '@fzf-border-label')
+    assert_equal "\#{@fzf-border-label}", pane_option(pane, 'pane-border-format')
     title = IO.popen(['tmux', 'display-message', '-p', '-t', pane, "\#{pane_title}"], &:read)
-    assert_equal ' #fzf-label 100% ', title.chomp
+    refute_equal ' #fzf-label 100% ', title.chomp
-    format = IO.popen(['tmux', 'show-options', '-p', '-t', pane, 'pane-border-format'], &:read)
+    tmux.send_keys :Enter
-    assert_includes format, "\#{pane_title}"
+    assert_equal '1', fzf_output
+  end
+
+  def test_floating_pane_change_border_label
+    tmux.send_keys "seq 100 | #{fzf(%(--popup center,80% --margin 0 --bind 'space:change-border-label( #[fg=red] 100% )'))}", :Enter
+    tmux.until { |lines| assert_equal 100, lines.item_count }
+    pane = floating_pane
+    refute_nil pane
+    assert_equal '', pane_option(pane, '@fzf-border-label')
+    tmux.send_keys :Space
+    wait { assert_equal ' ##[fg=red] 100% ', pane_option(pane, '@fzf-border-label') }
+    tmux.send_keys :Enter
+    assert_equal '1', fzf_output
+  end
+
+  # A program running in the pane owns the pane title, but not the label
+  def test_floating_pane_border_label_not_affected_by_title
+    tmux.send_keys "seq 100 | #{fzf(%(--popup center,80% --margin 0 --border-label ' label ' --bind 'space:execute-silent(printf "\\033]2;hijacked\\033\\\\" > /dev/tty)'))}", :Enter
+    tmux.until { |lines| assert_equal 100, lines.item_count }
+    pane = floating_pane
+    refute_nil pane
+    tmux.send_keys :Space
+    wait do
+      title = IO.popen(['tmux', 'display-message', '-p', '-t', pane, "\#{pane_title}"], &:read)
+      assert_equal 'hijacked', title.chomp
+    end
+    assert_equal ' label ', pane_option(pane, '@fzf-border-label')
     tmux.send_keys :Enter
     assert_equal '1', fzf_output
   end
@@ -79,6 +112,12 @@ class TestTmux < TestInteractive
 
   private
 
+  # stderr is merged in so that an unset option, which prints 'invalid
+  # option' to stderr and nothing to stdout, is not read as an empty value
+  def pane_option(pane, name)
+    IO.popen(['tmux', 'show-options', '-p', '-t', pane, '-v', name], err: %i[child out], &:read).chomp
+  end
+
   def floating_pane
     format = "\#{pane_id} \#{pane_floating_flag}"
     lines = IO.popen(['tmux', 'list-panes', '-t', tmux.win, '-F', format]) { |io| io.readlines(chomp: true) }