PDO MySQL: Make sure nextRowset() works with partially consumed result

This was already working in all cases apart from native prepared
statements with unbuffered queries. In that case invoking
stmt_free_result() addresses the issue.

Author: nikic

ext/pdo_mysql/mysql_statement.c

@@ -349,6 +349,15 @@ static int pdo_mysql_stmt_next_rowset(pdo_stmt_t *stmt) /* {{{ */
 	PDO_DBG_ENTER("pdo_mysql_stmt_next_rowset");
 	PDO_DBG_INF_FMT("stmt=%p", S->stmt);
 
+	/* ensure that we free any previous unfetched results */
+	if (S->stmt) {
+		mysql_stmt_free_result(S->stmt);
+	}
+	if (S->result) {
+		mysql_free_result(S->result);
+		S->result = NULL;
+	}
+
 #ifdef PDO_USE_MYSQLND
 	if (!H->emulate_prepare) {
 		if (!mysqlnd_stmt_more_results(S->stmt)) {
@@ -359,11 +368,6 @@ static int pdo_mysql_stmt_next_rowset(pdo_stmt_t *stmt) /* {{{ */
 			PDO_DBG_RETURN(0);
 		}
 
-		/* TODO - this code is stolen from execute() - see above */
-		if (S->result) {
-			mysql_free_result(S->result);
-			S->result = NULL;
-		}
 		{
 			/* for SHOW/DESCRIBE and others the column/field count is not available before execute */
 			int i;
@@ -394,17 +398,6 @@ static int pdo_mysql_stmt_next_rowset(pdo_stmt_t *stmt) /* {{{ */
 	}
 #endif
 
-/* ensure that we free any previous unfetched results */
-#ifndef PDO_USE_MYSQLND
-	if (S->stmt) {
-		mysql_stmt_free_result(S->stmt);
-	}
-#endif
-	if (S->result) {
-		mysql_free_result(S->result);
-		S->result = NULL;
-	}
-
 	if (!mysql_more_results(H->server)) {
 		/* No more results */
 		PDO_DBG_RETURN(0);

ext/pdo_mysql/tests/pdo_mysql_stmt_nextrowset.phpt

@@ -57,6 +57,11 @@ if (!MySQLPDOTest::isPDOMySQLnd())
         } while ($stmt->nextRowSet());
         var_dump($stmt->nextRowSet());
 
+        echo "Skip fetchAll(): ";
+        unset($stmt);
+        $stmt = $db->query('CALL p()');
+        var_dump($stmt->nextRowSet());
+        $stmt->closeCursor();
     }
 
     try {
@@ -160,6 +165,7 @@ array(3) {
 array(0) {
 }
 bool(false)
+Skip fetchAll(): bool(true)
 array(1) {
   [0]=>
   array(1) {
@@ -211,6 +217,7 @@ array(3) {
 array(0) {
 }
 bool(false)
+Skip fetchAll(): bool(true)
 Native PS...
 array(1) {
   [0]=>
@@ -263,6 +270,7 @@ array(3) {
 array(0) {
 }
 bool(false)
+Skip fetchAll(): bool(true)
 array(1) {
   [0]=>
   array(1) {
@@ -314,4 +322,5 @@ array(3) {
 array(0) {
 }
 bool(false)
+Skip fetchAll(): bool(true)
 done!