aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorBruno Haible <bruno@clisp.org>2021-01-07 02:06:17 +0100
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2021-02-04 16:44:24 -0300
commit1b3fc33f810b605e0e6dfcba96dddae432ccaab3 (patch)
tree00ef0dc42d3fb920c9294b9b90bbfe0f74aa7414
parent5ec029c8835b71d7a3d6036c9358198b4d9e59fc (diff)
downloadglibc-1b3fc33f810b605e0e6dfcba96dddae432ccaab3.tar
glibc-1b3fc33f810b605e0e6dfcba96dddae432ccaab3.tar.gz
glibc-1b3fc33f810b605e0e6dfcba96dddae432ccaab3.tar.bz2
glibc-1b3fc33f810b605e0e6dfcba96dddae432ccaab3.zip
argp: Don't rely on undefined behaviour of _tolower().
Patch by Eric Blake <https://lists.gnu.org/archive/html/bug-gnulib/2009-09/msg00287.html>. * argp/argp-help.c (hol_entry_cmp): Don't use _tolower on values that are not upper-case. Pass correct range to tolower. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
-rw-r--r--argp/argp-help.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/argp/argp-help.c b/argp/argp-help.c
index f417e1294c..5844d5ba1c 100644
--- a/argp/argp-help.c
+++ b/argp/argp-help.c
@@ -780,13 +780,11 @@ hol_entry_cmp (const struct hol_entry *entry1,
first, but as they're not displayed, it doesn't matter where
they are. */
{
- char first1 = short1 ? short1 : long1 ? *long1 : 0;
- char first2 = short2 ? short2 : long2 ? *long2 : 0;
-#ifdef _tolower
- int lower_cmp = _tolower (first1) - _tolower (first2);
-#else
+ unsigned char first1 = short1 ? short1 : long1 ? *long1 : 0;
+ unsigned char first2 = short2 ? short2 : long2 ? *long2 : 0;
+ /* Use tolower, not _tolower, since the latter has undefined
+ behaviour for characters that are not uppercase letters. */
int lower_cmp = tolower (first1) - tolower (first2);
-#endif
/* Compare ignoring case, except when the options are both the
same letter, in which case lower-case always comes first. */
return lower_cmp ? lower_cmp : first2 - first1;