Zero padding in replication origin's checkpointed on disk-state.

anarazel · anarazel · commit 81ff04deda21 · 2017-04-23T15:54:58.000-07:00
This seems to be largely cosmetic, avoiding valgrind bleats and the like. The uninitialized padding influences the CRC of the on-disk entry, but because it's also used when verifying the CRC, that doesn't cause spurious failures. Backpatch nonetheless. It's a bit unfortunate that contrib/test_decoding/sql/replorigin.sql doesn't exercise the checkpoint path, but checkpoints are fairly expensive on weaker machines, and we'd have to stop/start for that to be meaningful. Author: Andres Freund Discussion: https://postgr.es/m/20170422183123.w2jgiuxtts7qrqaq@alap3.anarazel.de Backpatch: 9.5, where replication origins were introduced
diff --git a/src/backend/replication/logical/origin.c b/src/backend/replication/logical/origin.c
@@ -566,6 +566,9 @@ CheckPointReplicationOrigin(void)
 		if (curstate->roident == InvalidRepOriginId)
 			continue;
 
+		/* zero, to avoid uninitialized padding bytes */
+		memset(&disk_state, 0, sizeof(disk_state));
+
 		LWLockAcquire(&curstate->lock, LW_SHARED);
 
 		disk_state.roident = curstate->roident;
