commit a991ce9c083bb8c02b1b1ec34ed35728197050f3
author zeertzjq <zeertzjq@outlook.com> Fri Oct 06 19:16:36 2023 +0200
committer Christian Brabandt <cb@256bit.org> Fri Oct 06 19:18:12 2023 +0200
tree 86b81d3c944a52d370959307b44136356cd27976
parent ac9c6d5c786a016ca1dce297d167a5a963881f7e

patch 9.0.1995: Invalid memory access with empty 'foldexpr'

Problem:  Invalid memory access when 'foldexpr' returns empty string.
Solution: Check for NUL.

closes: #13293

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

src/eval.c

diff --git a/src/eval.c b/src/eval.c
index 19ab015..a9f7112 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -968,7 +968,7 @@
 	    // If the result is a string, check if there is a non-digit before
 	    // the number.
 	    s = tv.vval.v_string;
-	    if (!VIM_ISDIGIT(*s) && *s != '-')
+	    if (*s != NUL && !VIM_ISDIGIT(*s) && *s != '-')
 		*cp = *s++;
 	    retval = atol((char *)s);
 	}

src/testdir/test_fold.vim

diff --git a/src/testdir/test_fold.vim b/src/testdir/test_fold.vim
index 398a0c2..cb29d43 100644
--- a/src/testdir/test_fold.vim
+++ b/src/testdir/test_fold.vim
Binary files differ

src/version.c

diff --git a/src/version.c b/src/version.c
index 057cae5..ce13dcc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1995,
+/**/
     1994,
 /**/
     1993,