From 93bcca389f1f69f53141b51acc91633ddca2bd94 Mon Sep 17 00:00:00 2001
From: Trond Norbye <trond.norbye@sun.com>
Date: Mon, 23 Mar 2009 09:38:04 +0100
Subject: [PATCH] Use ptr->root->result if the caller didn't provide a result
 structure to memcached_read_one_response

---
 libmemcached/memcached_response.c | 12 +++-----
 tests/function.c                  | 46 +++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/libmemcached/memcached_response.c b/libmemcached/memcached_response.c
index e9f82b0a..cb5a8672 100644
--- a/libmemcached/memcached_response.c
+++ b/libmemcached/memcached_response.c
@@ -21,6 +21,9 @@ memcached_return memcached_read_one_response(memcached_server_st *ptr,
 {
   memcached_server_response_decrement(ptr);
 
+  if (result == NULL)
+    result = &ptr->root->result;
+
   memcached_return rc;
   if (ptr->root->flags & MEM_BINARY_PROTOCOL)
     rc= binary_read_one_response(ptr, buffer, buffer_length, result);
@@ -81,16 +84,9 @@ static memcached_return textual_read_one_response(memcached_server_st *ptr,
   case 'V': /* VALUE || VERSION */
     if (buffer[1] == 'A') /* VALUE */
     {
-      memcached_return rc;
-
       /* We add back in one because we will need to search for END */
       memcached_server_response_increment(ptr);
-      if (result)
-        rc= value_fetch(ptr, buffer, result);
-      else
-        rc= value_fetch(ptr, buffer, &ptr->root->result);
-
-      return rc;
+      return value_fetch(ptr, buffer, result);
     }
     else if (buffer[1] == 'E') /* VERSION */
     {
diff --git a/tests/function.c b/tests/function.c
index faa45494..20637c8f 100644
--- a/tests/function.c
+++ b/tests/function.c
@@ -961,6 +961,51 @@ static test_return  get_test4(memcached_st *memc)
   return 0;
 }
 
+/*
+ * This test verifies that memcached_read_one_response doesn't try to
+ * dereference a NIL-pointer if you issue a multi-get and don't read out all
+ * responses before you execute a storage command.
+ */
+static test_return get_test5(memcached_st *memc)
+{
+  /*
+  ** Request the same key twice, to ensure that we hash to the same server
+  ** (so that we have multiple response values queued up) ;-)
+  */
+  char *keys[]= { "key", "key" };
+  size_t lengths[]= { 3, 3 };
+  uint32_t flags;
+  size_t rlen;
+
+  memcached_return rc= memcached_set(memc, keys[0], lengths[0], 
+                                     keys[0], lengths[0], 0, 0);
+  assert(rc == MEMCACHED_SUCCESS);
+  rc= memcached_mget(memc, keys, lengths, 2);
+
+  memcached_result_st results_obj;
+  memcached_result_st *results;
+  results=memcached_result_create(memc, &results_obj);
+  assert(results);
+  results=memcached_fetch_result(memc, &results_obj, &rc);
+  assert(results);
+  memcached_result_free(&results_obj);
+
+  /* Don't read out the second result, but issue a set instead.. */
+  rc= memcached_set(memc, keys[0], lengths[0], keys[0], lengths[0], 0, 0);
+  assert(rc == MEMCACHED_SUCCESS);
+
+  char *val= memcached_get_by_key(memc, keys[0], lengths[0], "yek", 3,
+                                  &rlen, &flags, &rc);
+  assert(val == NULL);
+  assert(rc == MEMCACHED_NOTFOUND);
+  val= memcached_get(memc, keys[0], lengths[0], &rlen, &flags, &rc);
+  assert(val != NULL);
+  assert(rc == MEMCACHED_SUCCESS);
+  free(val);
+
+  return TEST_SUCCESS;
+}
+
 /* Do not copy the style of this code, I just access hosts to testthis function */
 static test_return  stats_servername_test(memcached_st *memc)
 {
@@ -3579,6 +3624,7 @@ test_st tests[] ={
   {"get2", 0, get_test2 },
   {"get3", 0, get_test3 },
   {"get4", 0, get_test4 },
+  {"partial mget", 0, get_test5 },
   {"stats_servername", 0, stats_servername_test },
   {"increment", 0, increment_test },
   {"decrement", 0, decrement_test },
-- 
2.30.2