Backport of:

------------------------------------------------------------
revno: 2597.42.4
committer: davi@mysql.com/endora.local
timestamp: Tue 2008-04-15 17:29:42 -0300
message:
Bug#36004 mysql_stmt_prepare resets the list of warnings

Although the manual says that "the list of messages is reset
for each new statement that uses a table", the list of messages
is being unconditionally reset for prepare commands.

The solution is to enforce that the prepare command will only
reset the message list if the statement being prepared uses
a table or a warning is pushed.

tests/mysql_client_test.c

@@ -18392,9 +18392,51 @@ static void test_wl4166_4()
 }
 
 /**
-  Bug#38486 Crash when using cursor protocol
+  Bug#36004 mysql_stmt_prepare resets the list of warnings
 */
 
+static void test_bug36004()
+{
+  int rc, warning_count= 0;
+  MYSQL_STMT *stmt;
+
+  DBUG_ENTER("test_bug36004");
+  myheader("test_bug36004");
+
+  rc= mysql_query(mysql, "drop table if exists inexistant");
+  myquery(rc);
+
+  DIE_UNLESS(mysql_warning_count(mysql) == 1);
+  query_int_variable(mysql, "@@warning_count", &warning_count);
+  DIE_UNLESS(warning_count);
+
+  stmt= mysql_simple_prepare(mysql, "select 1");
+  check_stmt(stmt);
+
+  DIE_UNLESS(mysql_warning_count(mysql) == 0);
+  query_int_variable(mysql, "@@warning_count", &warning_count);
+  DIE_UNLESS(warning_count);
+
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+
+  DIE_UNLESS(mysql_warning_count(mysql) == 0);
+  mysql_stmt_close(stmt);
+
+  query_int_variable(mysql, "@@warning_count", &warning_count);
+  DIE_UNLESS(warning_count);
+
+  stmt= mysql_simple_prepare(mysql, "drop table if exists inexistant");
+  check_stmt(stmt);
+
+  query_int_variable(mysql, "@@warning_count", &warning_count);
+  DIE_UNLESS(warning_count == 0);
+  mysql_stmt_close(stmt);
+
+  DBUG_VOID_RETURN;
+}
+
+
 static void test_bug38486(void)
 {
   MYSQL_STMT *stmt;
@@ -19154,6 +19196,7 @@ static struct my_tests_st my_tests[]= {
   { "test_wl4166_2", test_wl4166_2 },
   { "test_wl4166_3", test_wl4166_3 },
   { "test_wl4166_4", test_wl4166_4 },
+  { "test_bug36004", test_bug36004 },
   { "test_wl4435",   test_wl4435 },
   { "test_wl4435_2", test_wl4435_2 },
   { "test_bug38486", test_bug38486 },