From: Dan Fandrich <dan@coneharvesters.com>
Date: Sat, 16 Sep 2023 07:08:26 +0000 (-0700)
Subject: http_aws_sigv4: fix sorting with empty parts
X-Git-Tag: curl-8_4_0~191
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c87920353883ef9d5aa952e724a8e2589d76add5;p=thirdparty%2Fcurl.git

http_aws_sigv4: fix sorting with empty parts

When comparing with an empty part, the non-empty one is always
considered greater-than. Previously, the two would be considered equal
which would randomly place empty parts amongst non-empty ones. This
showed as a test 439 failure on Solaris as it uses a different
implementation of qsort() that compares parts differently.

Fixes #11855
Closes #11868
---

diff --git a/lib/http_aws_sigv4.c b/lib/http_aws_sigv4.c
index f39d02cced..25c16a2b76 100644
--- a/lib/http_aws_sigv4.c
+++ b/lib/http_aws_sigv4.c
@@ -409,6 +409,11 @@ static int compare_func(const void *a, const void *b)
 {
   const struct pair *aa = a;
   const struct pair *bb = b;
+  /* If one element is empty, the other is always sorted higher */
+  if(aa->len == 0)
+    return -1;
+  if(bb->len == 0)
+    return 1;
   return strncmp(aa->p, bb->p, aa->len < bb->len ? aa->len : bb->len);
 }