Remove dead code.

These memory context switches are useless in the wake of commit
1cff1b95a.  Noted by Jesper Pedersen.

Discussion: https://postgr.es/m/f078ce63-9e04-0f3e-d200-d7ee66279abe@redhat.com

diff --git a/src/backend/commands/async.c b/src/backend/commands/async.c
index 34e5ca9edb36e812c9a6292df25419bea485eaf6..6e9c580ec6d04029ddf2b0e40f2caca3f4b59815 100644 (file)
--- a/src/backend/commands/async.c
+++ b/src/backend/commands/async.c
@@ -693,15 +693,8 @@ pg_listening_channels(PG_FUNCTION_ARGS)
    /* stuff done only on the first call of the function */
    if (SRF_IS_FIRSTCALL())
    {
-       MemoryContext oldcontext;
-
        /* create a function context for cross-call persistence */
        funcctx = SRF_FIRSTCALL_INIT();
-
-       /* switch to memory context appropriate for multiple function calls */
-       oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
-
-       MemoryContextSwitchTo(oldcontext);
    }
 
    /* stuff done on every call of the function */