+2020-12-08 Bruno Haible <bruno@clisp.org>
+
+ 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>.
+ * lib/argp-help.c (hol_entry_cmp): Don't use _tolower on values that are
+ not upper-case. Pass correct range to tolower.
+
2020-12-07 Bruno Haible <bruno@clisp.org>
unicodeio: Fix wrong result on FreeBSD.
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;