Ensure that a plpgsql LOOP with an empty body still executes at least

one CHECK_FOR_INTERRUPTS() call, so that you can control-C out of the
loop.  Reported by Merlin Moncure.

diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 663fe9684b2786f9c82478aa89b0c3bdfa955941..0bbcde834e5f1456b9d4c4c3ca29b43ecb65581a 100644 (file)
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -974,6 +974,17 @@ exec_stmts(PLpgSQL_execstate * estate, List *stmts)
 {
        ListCell   *s;
 
+       if (stmts == NIL)
+       {
+               /*
+                * Ensure we do a CHECK_FOR_INTERRUPTS() even though there is no
+                * statement.  This prevents hangup in a tight loop if, for instance,
+                * there is a LOOP construct with an empty body.
+                */
+               CHECK_FOR_INTERRUPTS();
+               return PLPGSQL_RC_OK;
+       }
+
        foreach(s, stmts)
        {
                PLpgSQL_stmt *stmt = (PLpgSQL_stmt *) lfirst(s);