From 3b18a7d8c9608ed0bf13d546018f44e703c62e11 Mon Sep 17 00:00:00 2001
From: Saya Andy <saya.andy@posteo.com>
Date: Mon, 7 Sep 2026 20:26:15 +0700
Subject: diff: add a flip link to the refs panel

The from and to refs of a diff can only be swapped by editing the
url by hand.  Add a flip link to the refs panel that opens the same
diff with the refs swapped, carrying the current head and options.
---
 tests/t0106-diff.sh | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

(limited to 'tests/t0106-diff.sh')

diff --git a/tests/t0106-diff.sh b/tests/t0106-diff.sh
index e4751e9..1100596 100755
--- a/tests/t0106-diff.sh
+++ b/tests/t0106-diff.sh
@@ -45,6 +45,15 @@ test_expect_success 'ref picker: auto-submit on change' '
 	grep "onchange=.this.form.submit()." tmp
 '
 
+test_expect_success 'flip link present' '
+	grep "<a title=.swap from and to. class=.button. href=./foo/diff/?" tmp
+'
+
+test_expect_success 'flip link swaps the default refs' '
+	old=$(git --git-dir="$PWD/repos/foo/.git" rev-parse master~1) &&
+	grep "/foo/diff/?id=$old&amp;id2=master" tmp
+'
+
 test_expect_success 'compare two refs: foo/diff?id=master&id2=HEAD' '
 	cgit_query "url=foo/diff&id=master&id2=HEAD" >tmp
 '
@@ -77,4 +86,16 @@ test_expect_success 'diff with HEAD and root shows content' '
 	grep "diffstat" tmp
 '
 
+test_expect_success 'flip link swaps explicit refs' '
+	cgit_query "url=foo/diff&id=master&id2=HEAD" >tmp &&
+	new=$(git --git-dir="$PWD/repos/foo/.git" rev-parse HEAD) &&
+	grep "/foo/diff/?id=$new&amp;id2=master" tmp
+'
+
+test_expect_success 'flip link omits id for a diff against a root commit' '
+	root=$(git --git-dir="$PWD/repos/foo/.git" rev-list --max-parents=0 HEAD) &&
+	cgit_query "url=foo/diff&id=$root" >tmp &&
+	grep "href=./foo/diff/?id2=$root." tmp
+'
+
 test_done
-- 
cgit v1.3.1+16