Fix bg-transform reload/exclude

Async callbacks fire a later iteration than the one that scheduled
them, so newCommand/reloadSync/denylist must persist across iterations.

  fzf --bind 'space:bg-transform:echo reload:date'

src/terminal.go

@@ -6366,12 +6366,18 @@ func (t *Terminal) Loop() error {
 		needBarrier = false
 	}
 
-	// These variables are defined outside the loop to be accessible from closures
+	// These variables are defined outside the loop to be accessible from closures.
+	// In particular, async bg-transform callbacks run in a later iteration than
+	// the one that scheduled them, but still need to mutate state that the
+	// loop-end reload/event dispatch reads.
 	events := []util.EventType{}
 	changed := false
 	var newNth *[]Range
 	var newWithNth *withNthSpec
 	var newHeaderLines *int
+	var newCommand *commandSpec
+	var reloadSync bool
+	var denylist []int32
 	req := func(evts ...util.EventType) {
 		for _, event := range evts {
 			events = append(events, event)
@@ -6383,16 +6389,16 @@ func (t *Terminal) Loop() error {
 
 	// The main event loop
 	for loopIndex := int64(0); looping; loopIndex++ {
-		var newCommand *commandSpec
-		var reloadSync bool
 		events = []util.EventType{}
 		changed = false
 		newNth = nil
 		newWithNth = nil
 		newHeaderLines = nil
+		newCommand = nil
+		reloadSync = false
+		denylist = nil
 		beof := false
 		queryChanged := false
-		denylist := []int32{}
 
 		// Special handling of --sync. Activate the interface on the second tick.
 		if loopIndex == 1 && t.deferActivation() {

test/test_core.rb

@@ -2153,6 +2153,24 @@ class TestCore < TestInteractive
     tmux.until { |lines| assert lines.any_include?('a b c') || lines.any_include?('d e f') }
   end
 
+  # Regression: actions emitted by bg-transform must affect the iteration that
+  # processes the async result, not the (no-longer-active) iteration that
+  # scheduled the transform. Covers reload (newCommand) and exclude (denylist).
+  def test_bg_transform_action_output
+    tmux.send_keys %(seq 5 | #{FZF} --bind 'a:bg-transform(echo reload:seq 10 20),b:bg-transform(echo exclude)'), :Enter
+    tmux.until { |lines| assert_equal 5, lines.item_count }
+    tmux.send_keys :a
+    tmux.until do |lines|
+      assert_equal 11, lines.match_count
+      assert_includes lines, '> 10'
+    end
+    tmux.send_keys :b
+    tmux.until do |lines|
+      assert_equal 10, lines.match_count
+      assert_includes lines, '> 11'
+    end
+  end
+
   def test_change_with_nth_search
     input = [
       'alpha bravo charlie',