patch 9.1.0006: is*() and to*() function may be unsafe Commit: https://github.com/vim/vim/commit/184f71cc6868a240dc872ed2852542bbc1d43e28 Author: Keith Thompson <Keith.S.Thompson@gmail.com> Date: Thu Jan 4 21:19:04 2024 +0100 patch 9.1.0006: is*() and to*() function may be unsafe Problem: is*() and to*() function may be unsafe Solution: Add SAFE_* macros and start using those instead (Keith Thompson) Use SAFE_() macros for is*() and to*() functions The standard is*() and to*() functions declared in <ctype.h> have undefined behavior for negative arguments other than EOF. If plain char is signed, passing an unchecked value from argv for from user input to one of these functions has undefined behavior. Solution: Add SAFE_*() macros that cast the argument to unsigned char. Most implementations behave sanely for negative arguments, and most character values in practice are non-negative, but it's still best to avoid undefined behavior. The change from #13347 has been omitted, as this has already been separately fixed in commit ac709e2fc0db6d31abb7da96f743c40956b60c3a (v9.0.2054) fixes: #13332 closes: #13347 Signed-off-by: Keith Thompson <Keith.S.Thompson@gmail.com> Signed-off-by: Christian Brabandt <cb@256bit.org>

--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -3159,7 +3159,7 @@ get_cmd_count(char_u *line, exarg_T *eap
     // skip over colons and white space
     for (p = line; *p == ':' || VIM_ISWHITE(*p); ++p)
 	;
-    if (!isdigit(*p))
+    if (!SAFE_isdigit(*p))
     {
 	// The command or modifiers must be following.  Assume a lower case
 	// character means there is a modifier.