From: Steinar H. Gunderson <sesse@google.com>
Date: Sat, 29 Sep 2007 13:38:17 +0000 (+0000)
Subject: Handle the root of the DNS tree correctly in ares_expand_name.
X-Git-Tag: curl-7_17_1~166
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6ecea9453ba158edb1949dcac2fc46e1ad4b5bf2;p=curl

Handle the root of the DNS tree correctly in ares_expand_name.
---

diff --git a/ares/ares_expand_name.c b/ares/ares_expand_name.c
index 7fe025fe4..ffa26e6b5 100644
--- a/ares/ares_expand_name.c
+++ b/ares/ares_expand_name.c
@@ -74,6 +74,14 @@ int ares_expand_name(const unsigned char *encoded, const unsigned char *abuf,
     return ARES_ENOMEM;
   q = *s;
 
+  if (len == 0) {
+    // RFC2181 says this should be ".": the root of the DNS tree.
+    // Since this function strips trailing dots though, it becomes ""
+    q[0] = '\0';
+    *enclen = 1;  // the caller should move one byte to get past this
+    return ARES_SUCCESS;
+  }
+
   /* No error-checking necessary; it was all done by name_length(). */
   p = encoded;
   while (*p)