Fix buggy logic in isTempNamespaceInUse()

The logic introduced in this routine as of 246a6c8 would report an
incorrect result when a session calls it to check if the temporary
namespace owned by the session is in use or not.  It is possible to
optimize more the routine in this case to avoid a PGPROC lookup, but
let's keep the logic simple.  As this routine is used only by autovacuum
for now, there were no live bugs, still let's be correct for any future
code involving it.

Author: Michael Paquier
Reviewed-by: Julien Rouhaud
Discussion: https://postgr.es/m/20200113093703.GA41902@paquier.xyz
Backpatch-through: 11

diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index c82f9fc4b524c9463dce9fc070f356d65fb0ce7c..e70243a0084a769f5e9f45b3b87bef7c21a5db3b 100644 (file)
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -3235,8 +3235,8 @@ isTempNamespaceInUse(Oid namespaceId)
 
    backendId = GetTempNamespaceBackendId(namespaceId);
 
-   if (backendId == InvalidBackendId ||
-       backendId == MyBackendId)
+   /* No such temporary namespace? */
+   if (backendId == InvalidBackendId)
        return false;
 
    /* Is the backend alive? */