Address copilot comments

Callers cannot detect plugin-side behavior. fzf#exec() reports the version
of the binary, not of this plugin, and everything else here is script-local.
fzf.vim needs to know whether fzf#run is asynchronous in popup mode before
offering a key binding that depends on it.

The value was only ever read through the exists() guard, so raising it from
1 breaks nothing.

src/tui/light.go

@@ -26,7 +26,6 @@ const (
 	offsetPollTries = 10
 	queryTimeout    = 500 * time.Millisecond
 	maxInputBuffer  = 1024 * 1024
-	escapeLookback  = 256
 	maxSelectTries  = 100
 )
 
@@ -339,45 +338,6 @@ func getEnv(name string, defaultValue int) int {
 	return atoi(env, defaultValue)
 }
 
-// Bytes of a CSI sequence: parameter and intermediate bytes continue it, a
-// final byte ends it. Order is not enforced. Strictness would only make fzf
-// give up on a sequence it could have framed.
-//
-// https://vt100.net/emu/dec_ansi_parser
-func csiContinues(b byte) bool { return b >= 0x20 && b <= 0x3f }
-func csiFinal(b byte) bool     { return b >= 0x40 && b <= 0x7e }
-
-// incompleteEscape reports whether the buffer ends in an escape sequence that
-// has not been terminated yet. The read loop keeps waiting in that case, so the
-// parser is never handed a fragment to guess at.
-func incompleteEscape(buffer []byte) bool {
-	// Only the tail can hold a sequence still arriving. This runs once per byte
-	// read, so scanning all of a large paste would make the read quadratic.
-	tail := buffer
-	if len(tail) > escapeLookback {
-		tail = tail[len(tail)-escapeLookback:]
-	}
-	start := bytes.LastIndexByte(tail, Esc.Byte())
-	if start < 0 || len(tail)-start < 2 {
-		return false
-	}
-	switch tail[start+1] {
-	case '[':
-		for _, b := range tail[start+2:] {
-			if csiFinal(b) {
-				return false
-			}
-			if !csiContinues(b) {
-				return false // malformed, do not wait for a terminator
-			}
-		}
-		return true
-	case 'O':
-		return len(tail)-start < 3
-	}
-	return false
-}
-
 func (r *LightRenderer) getBytes(cancellable bool) ([]byte, getCharResult, error) {
 	return r.getBytesInternal(cancellable, r.buffer, false)
 }
@@ -418,13 +378,6 @@ func (r *LightRenderer) getBytesInternal(cancellable bool, buffer []byte, nonblo
 			retries = 0
 		}
 		buffer = append(buffer, byte(c))
-		// Keep waiting while a sequence is still arriving. Dropping the budget
-		// after every byte left fzf parsing whatever the read happened to end on.
-		// Past the introducer this is not the ESC key, so the wait costs no
-		// Escape latency and ESCDELAY=0 must not reduce it to nothing.
-		if retries == 0 && incompleteEscape(buffer) {
-			retries = max(r.escDelay, defaultEscDelay) / escPollInterval
-		}
 		pc = c
 
 		// This should never happen under normal conditions,

src/tui/light_escape_test.go

@@ -1,53 +0,0 @@
-package tui
-
-import (
-	"strings"
-	"testing"
-)
-
-func TestIncompleteEscape(t *testing.T) {
-	for _, c := range []struct {
-		buffer string
-		want   bool
-	}{
-		// Complete sequences: nothing to wait for
-		{"\x1b[A", false},
-		{"\x1bOA", false},
-		{"\x1b[1;5A", false},
-		{"\x1b[200~", false},
-		{"\x1b[<0;1;1M", false},
-		{"\x1b[12;34R", false},
-		{"\x1b[?2004;2$y", false},
-		{"\x1b[?1;2c", false},
-
-		// Fragments: keep waiting
-		{"\x1b[", true},
-		{"\x1b[?", true},
-		{"\x1b[1;", true},
-		{"\x1b[?2004;2$", true},
-		{"\x1bO", true},
-		{"\x1b[<0;1;", true},
-
-		// Only the trailing sequence matters
-		{"ab\x1b[?2004;2$", true},
-		{"\x1b[A\x1b[", true},
-		{"\x1b[A\x1b[B", false},
-
-		// Long buffers: only the tail is scanned, so an introducer further
-		// back than escapeLookback is not waited for
-		{strings.Repeat("a", 100000), false},
-		{"\x1b[" + strings.Repeat("a", 100000), false},
-		{strings.Repeat("a", 100000) + "\x1b[1;", true},
-
-		// Not a sequence fzf waits on
-		{"", false},
-		{"abc", false},
-		{"\x1b", false},      // lone ESC, handled by the existing escDelay branch
-		{"\x1ba", false},     // ALT-a
-		{"\x1b[\x01", false}, // malformed, do not stall on it
-	} {
-		if got := incompleteEscape([]byte(c.buffer)); got != c.want {
-			t.Errorf("incompleteEscape(%q) = %v, want %v", c.buffer, got, c.want)
-		}
-	}
-}