[PATCH 2/2] Cygwin: implement case-insensitive Unicode user and group name matching

[Darren Tucker]

On Fri, Feb 22, 2019 at 10:29:46AM +0100, Corinna Vinschen wrote:
> On Feb 22 16:02, Darren Tucker wrote:
[...]
> > How's this?  If we push the match_usergroup_pattern_list() function up
> > to OpenBSD it should mean most future diffs will apply cleanly.
> 
> I like this a lot.
> 
> But that also means the cygwin_match_pattern_list function will be
> called only for user and group names, and that in turn means the cygwin
> function is always called for case-insensitive operation.
> 
> How's this?  It's just tweaking your patch a bit, simplifying the Cygwin
> code.

Looks good, I've committed it.  One final tweak: replace alloca with
xcalloc since it checks for integer overflow, will fail instead of blowing
the stack on large allocs and is likely at a less well-known location.
Also include stdlib.h for the prototype for free().

diff --git a/openbsd-compat/bsd-cygwin_util.c b/openbsd-compat/bsd-cygwin_util.c
index 1e4cdc92..54628e26 100644
--- a/openbsd-compat/bsd-cygwin_util.c
+++ b/openbsd-compat/bsd-cygwin_util.c
@@ -37,6 +37,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <stdarg.h>
+#include <stdlib.h>
 #include <wchar.h>
 #include <wctype.h>
 
@@ -191,16 +192,20 @@ _match_pattern(const char *s, const char *pattern)
 	wchar_t *ws;
 	wchar_t *wpattern;
 	size_t len;
+	int ret;
 
 	if ((len = mbstowcs(NULL, s, 0)) < 0)
 		return 0;
-	ws = (wchar_t *) alloca((len + 1) * sizeof (wchar_t));
+	ws = (wchar_t *) xcalloc(len + 1, sizeof (wchar_t));
 	mbstowcs(ws, s, len + 1);
 	if ((len = mbstowcs(NULL, pattern, 0)) < 0)
 		return 0;
-	wpattern = (wchar_t *) alloca((len + 1) * sizeof (wchar_t));
+	wpattern = (wchar_t *) xcalloc(len + 1, sizeof (wchar_t));
 	mbstowcs(wpattern, pattern, len + 1);
-	return __match_pattern (ws, wpattern);
+	ret = __match_pattern (ws, wpattern);
+	free(ws);
+	free(wpattern);
+	return ret;
 }
 
 /*

-- 
Darren Tucker (dtucker at dtucker.net)
GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860  37F4 9357 ECEF 11EA A6FA (new)
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.