commit 00624a2fa08d04bdded240d474e9cfdc193dbe10
author zeertzjq <zeertzjq@outlook.com> Thu Nov 23 20:47:16 2023 +0100
committer Christian Brabandt <cb@256bit.org> Thu Nov 23 20:47:16 2023 +0100
tree 17b6983aab398412244607f29ce699ad7ed60ef1
parent 40ed6711bd385051021691980e8ce16375b4b510

patch 9.0.2126: unused assignments when checking 'listchars'

Problem:  Unused assignments when checking the value of 'listchars'.
Solution: Loop only once when just checking the value.  Add a test to
          check that this change doesn't cause double-free.

closes: #13559

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/screen.c

diff --git a/src/screen.c b/src/screen.c
index fd69cf0..ac24a16 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -4726,7 +4726,7 @@
     }
 
     // first round: check for valid value, second round: assign values
-    for (round = 0; round <= 1; ++round)
+    for (round = 0; round <= (apply ? 1 : 0); ++round)
     {
 	if (round > 0)
 	{
@@ -4913,11 +4913,6 @@
 	    wp->w_fill_chars = fill_chars;
 	}
     }
-    else if (is_listchars)
-    {
-	vim_free(lcs_chars.multispace);
-	vim_free(lcs_chars.leadmultispace);
-    }
 
     return NULL;	// no error
 }

src/testdir/test_listchars.vim

diff --git a/src/testdir/test_listchars.vim b/src/testdir/test_listchars.vim
index 8628fb2..57ddcda 100644
--- a/src/testdir/test_listchars.vim
+++ b/src/testdir/test_listchars.vim
@@ -265,6 +265,11 @@
   call Check_listchars(expected, 5, 12)
   call assert_equal(expected, split(execute("%list"), "\n"))
 
+  " Changing the value of 'ambiwidth' twice shouldn't cause double-free when
+  " "leadmultispace" is specified.
+  set ambiwidth=double
+  set ambiwidth&
+
   " Test leadmultispace and lead and space
   normal ggdG
   set listchars&

src/version.c

diff --git a/src/version.c b/src/version.c
index 801ca36..8e35aaa 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2126,
+/**/
     2125,
 /**/
     2124,