If mysqli_stmt_prepare fails then the error is populated in conn not in stmt

However, mysqli_stmt_prepare only checks for errors in statement. If exception mode is enabled the exception is not triggered because of this flawed logic.
Fix: copy the error from conn to stmt. If mysqli_stmt_prepare is called from mysqli_prepare then it doesn't matter because we unset stmt immediately and check for errors in conn.

Author: kamil-tekiela

ext/mysqli/tests/mysqli_report.phpt

@@ -53,6 +53,8 @@ require_once('skipifconnectfailure.inc');
     mysqli_autocommit($link, true);
     mysqli_commit($link);
     mysqli_rollback($link);
+    $stmt = mysqli_stmt_init($link);
+    mysqli_stmt_prepare($stmt, "SELECT id FROM test WHERE id > ?");
     while(mysqli_more_results($link)) {
         mysqli_next_result($link);
         $res = mysqli_store_result($link);
@@ -81,6 +83,8 @@ require_once('skipifconnectfailure.inc');
     mysqli_autocommit($link, true);
     mysqli_commit($link);
     mysqli_rollback($link);
+    $stmt = mysqli_stmt_init($link);
+    mysqli_stmt_prepare($stmt, "SELECT id FROM test WHERE id > ?");
     while(mysqli_more_results($link)) {
         mysqli_next_result($link);
         $res = mysqli_store_result($link);
@@ -324,6 +328,8 @@ Warning: mysqli_commit(): (%s/%d): Commands out of sync; you can't run this comm
 
 Warning: mysqli_rollback(): (%s/%d): Commands out of sync; you can't run this command now in %s on line %d
 
+Warning: mysqli_stmt_prepare(): (%s/%d): Commands out of sync; you can't run this command now in %s on line %d
+
 Warning: mysqli_store_result(): (%s/%d): You have an error in your SQL syntax; check the manual that corresponds to your %s server version for the right syntax to use near 'FOO' at line 1 in %s on line %d
 
 Warning: mysqli_stmt_attr_set(): (%s/%d): Not implemented in %s on line %d

ext/mysqlnd/mysqlnd_ps.c

@@ -407,6 +407,7 @@ MYSQLND_METHOD(mysqlnd_stmt, prepare)(MYSQLND_STMT * const s, const char * const
 
 		ret = conn->command->stmt_prepare(conn, query_string);
 		if (FAIL == ret) {
+			COPY_CLIENT_ERROR(stmt->error_info, *conn->error_info);
 			goto fail;
 		}
 	}