Avoid palloc(0) when MaxBackends = 1.

diff --git a/src/backend/storage/lmgr/deadlock.c b/src/backend/storage/lmgr/deadlock.c
index 155b1a42ea6b72e192a66c450ec5ea3079f474cb..ca892b2cc0aa1881114677feb27e1d587532a57e 100644 (file)
--- a/src/backend/storage/lmgr/deadlock.c
+++ b/src/backend/storage/lmgr/deadlock.c
@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/storage/lmgr/deadlock.c,v 1.13 2002/09/04 20:31:25 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/storage/lmgr/deadlock.c,v 1.14 2002/10/03 19:17:55 tgl Exp $
  *
  * Interface:
  *
@@ -125,9 +125,11 @@ InitDeadLockChecking(void)
     * We need to consider rearranging at most MaxBackends/2 wait queues
     * (since it takes at least two waiters in a queue to create a soft
     * edge), and the expanded form of the wait queues can't involve more
-    * than MaxBackends total waiters.
+    * than MaxBackends total waiters.  (But avoid palloc(0) if
+    * MaxBackends = 1.)
     */
-   waitOrders = (WAIT_ORDER *) palloc((MaxBackends / 2) * sizeof(WAIT_ORDER));
+   waitOrders = (WAIT_ORDER *)
+       palloc(((MaxBackends + 1) / 2) * sizeof(WAIT_ORDER));
    waitOrderProcs = (PGPROC **) palloc(MaxBackends * sizeof(PGPROC *));
 
    /*