From: Junio C Hamano <junkio@cox.net>
Date: Tue, 06 Dec 2005 21:41:48 GMT
Subject: Re: [PATCH] Add compat/setenv.c, use in git.c.
Message-ID: <7vwtih299f.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <118833cc0512061310r6398f812ia47a84d3cfad1564@mail.gmail.com>

Morten Welinder <mwelinder@gmail.com> writes:

> The code looks wrong.  It assumes that pointers are no larger than ints.
> If pointers are larger than ints, the code does not necessarily compute
> a consistent ordering and qsort is allowed to do whatever it wants.
>
> Morten
>
>
>
> static int compare_object_pointers(const void *a, const void *b)
> {
> 	const struct object * const *pa = a;
> 	const struct object * const *pb = b;
> 	return *pa - *pb;
> }

Are you suggesting it to be done like this?

---
git diff
diff --git a/object.c b/object.c
index 427e14c..dac5c92 100644
--- a/object.c
+++ b/object.c
@@ -82,7 +82,12 @@ static int compare_object_pointers(const
 {
 	const struct object * const *pa = a;
 	const struct object * const *pb = b;
-	return *pa - *pb;
+	if (*pa == *pb)
+		return 0;
+	else if (*pa < *pb)
+		return -1;
+	else
+		return 1;
 }
 
 void set_object_refs(struct object *obj, struct object_refs *refs)