From af0014aba8bc49f6acb35f96cb9642bf3d163edd Mon Sep 17 00:00:00 2001
From: Junegunn Choi <junegunn.c@gmail.com>
Date: Sun, 3 Aug 2025 00:28:50 +0900
Subject: [PATCH] Fix a bug where you cannot unset the default `--nth` using
 `change-nth`

---
 CHANGELOG.md      |  1 +
 src/terminal.go   |  2 +-
 test/test_core.rb | 15 +++++++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ca524250..5d344de6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@ CHANGELOG
 0.65.1
 ------
 - Fixed incorrect `$FZF_CLICK_HEADER_WORD` and `$FZF_CLICK_FOOTER_WORD` when the header or footer contains ANSI escape sequences and tab characters.
+- Fixed a bug where you cannot unset the default `--nth` using `change-nth` action.
 
 0.65.0
 ------
diff --git a/src/terminal.go b/src/terminal.go
index 9c34eca0..0fd5d006 100644
--- a/src/terminal.go
+++ b/src/terminal.go
@@ -5726,7 +5726,7 @@ func (t *Terminal) Loop() error {
 				capture(true, func(expr string) {
 					// Split nth expression
 					tokens := strings.Split(expr, "|")
-					if nth, err := splitNth(tokens[0]); err == nil {
+					if nth, err := splitNth(tokens[0]); err == nil || len(expr) == 0 {
 						// Changed
 						newNth = &nth
 					} else {
diff --git a/test/test_core.rb b/test/test_core.rb
index 17578baf..d77bbcce 100644
--- a/test/test_core.rb
+++ b/test/test_core.rb
@@ -2045,4 +2045,19 @@ class TestCore < TestInteractive
     tmux.send_keys :b
     tmux.until { |lines| assert_includes lines, '> 9' }
   end
+
+  def test_change_nth_unset_default
+    tmux.send_keys %(echo foo bar | #{FZF} --nth 2 --query fb --bind space:change-nth:), :Enter
+    tmux.until do
+      assert_equal 1, it.item_count
+      assert_equal 0, it.match_count
+    end
+
+    tmux.send_keys :Space
+
+    tmux.until do
+      assert_equal 1, it.item_count
+      assert_equal 1, it.match_count
+    end
+  end
 end