From 4e8efe002e976de1a22dcce6a1e800aeb6acad70 Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Sat, 10 Aug 2024 06:35:51 +0800
Subject: [PATCH] vim-patch:9.1.0666: assert_equal() doesn't show multibyte
 string correctly (#30018)

Problem:  assert_equal() doesn't show multibyte string correctly
Solution: Properly advance over a multibyte char.
          (zeertzjq)

closes: vim/vim#15456

https://github.com/vim/vim/commit/9c4b2462bb498f44044616f7309d111d12170369
---
 src/nvim/testing.c               | 5 +++--
 test/old/testdir/test_assert.vim | 9 +++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/nvim/testing.c b/src/nvim/testing.c
index 4dc8984fa9..adbdd3e611 100644
--- a/src/nvim/testing.c
+++ b/src/nvim/testing.c
@@ -130,7 +130,7 @@ static void ga_concat_shorten_esc(garray_T *gap, const char *str)
     return;
   }
 
-  for (const char *p = str; *p != NUL; p++) {
+  for (const char *p = str; *p != NUL;) {
     int same_len = 1;
     const char *s = p;
     const int c = mb_cptr2char_adv(&s);
@@ -146,9 +146,10 @@ static void ga_concat_shorten_esc(garray_T *gap, const char *str)
       vim_snprintf(buf, NUMBUFLEN, "%d", same_len);
       ga_concat(gap, buf);
       ga_concat(gap, " times]");
-      p = s - 1;
+      p = s;
     } else {
       ga_concat_esc(gap, p, clen);
+      p += clen;
     }
   }
 }
diff --git a/test/old/testdir/test_assert.vim b/test/old/testdir/test_assert.vim
index bc79ef9296..fa63af687d 100644
--- a/test/old/testdir/test_assert.vim
+++ b/test/old/testdir/test_assert.vim
@@ -48,10 +48,19 @@ func Test_assert_equal()
   call assert_match("Expected 'bar' but got 'foo'", v:errors[0])
   call remove(v:errors, 0)
 
+  let s = 'αβγ'
+  call assert_equal(1, assert_equal('δεζ', s))
+  call assert_match("Expected 'δεζ' but got 'αβγ'", v:errors[0])
+  call remove(v:errors, 0)
+
   call assert_equal('XxxxxxxxxxxxxxxxxxxxxxX', 'XyyyyyyyyyyyyyyyyyyyyyyyyyX')
   call assert_match("Expected 'X\\\\\\[x occurs 21 times]X' but got 'X\\\\\\[y occurs 25 times]X'", v:errors[0])
   call remove(v:errors, 0)
 
+  call assert_equal('ΩωωωωωωωωωωωωωωωωωωωωωΩ', 'ΩψψψψψψψψψψψψψψψψψψψψψψψψψΩ')
+  call assert_match("Expected 'Ω\\\\\\[ω occurs 21 times]Ω' but got 'Ω\\\\\\[ψ occurs 25 times]Ω'", v:errors[0])
+  call remove(v:errors, 0)
+
   " special characters are escaped
   call assert_equal("\b\e\f\n\t\r\\\x01\x7f", 'x')
   call assert_match('Expected ''\\b\\e\\f\\n\\t\\r\\\\\\x01\\x7f'' but got ''x''', v:errors[0])