Fix regex code so it doesn't rely on strcasecmp. * lib/regex_internal.h: Include <langinfo.h> only if _LIBC is defined. Otherwise, include gnulib's langinfo.h. * lib/regcomp.c (init_dfa): Don't use strcasecmp, as it can have undesirable behavior in non-C locales. Instead, rely on locale_charset. * m4/regex.m4 (gl_PREREQ_REGEX): Don't require AM_LANGINFO_CODESET. * modules/regex (FILES): Remove m4/codeset.m4. (Depends-on): Add localcharset. Remove strcase.

--- a/lib/regex_internal.h
+++ b/lib/regex_internal.h
@@ -27,8 +27,10 @@
 #include <stdlib.h>
 #include <string.h>
 
-#if defined HAVE_LANGINFO_H || defined HAVE_LANGINFO_CODESET || defined _LIBC
+#ifdef _LIBC
 # include <langinfo.h>
+#else
+# include "localcharset.h"
 #endif
 #if defined HAVE_LOCALE_H || defined _LIBC
 # include <locale.h>