diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 55a46cef668..33a862c8ef6 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.215.2.6 2009/12/09 21:58:41 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/transam/xact.c,v 1.215.2.7 2010/01/24 21:49:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1919,35 +1919,38 @@ AbortTransaction(void)
 
 	/*
 	 * Post-abort cleanup.	See notes in CommitTransaction() concerning
-	 * ordering.
+	 * ordering.  We can skip all of it if the transaction failed before
+	 * creating a resource owner.
 	 */
+	if (TopTransactionResourceOwner != NULL)
+	{
+		CallXactCallbacks(XACT_EVENT_ABORT);
 
-	CallXactCallbacks(XACT_EVENT_ABORT);
+		ResourceOwnerRelease(TopTransactionResourceOwner,
+							 RESOURCE_RELEASE_BEFORE_LOCKS,
+							 false, true);
+		AtEOXact_Buffers(false);
+		AtEOXact_RelationCache(false);
+		AtEOXact_Inval(false);
+		smgrDoPendingDeletes(false);
+		AtEOXact_MultiXact();
+		ResourceOwnerRelease(TopTransactionResourceOwner,
+							 RESOURCE_RELEASE_LOCKS,
+							 false, true);
+		ResourceOwnerRelease(TopTransactionResourceOwner,
+							 RESOURCE_RELEASE_AFTER_LOCKS,
+							 false, true);
+		AtEOXact_CatCache(false);
 
-	ResourceOwnerRelease(TopTransactionResourceOwner,
-						 RESOURCE_RELEASE_BEFORE_LOCKS,
-						 false, true);
-	AtEOXact_Buffers(false);
-	AtEOXact_RelationCache(false);
-	AtEOXact_Inval(false);
-	smgrDoPendingDeletes(false);
-	AtEOXact_MultiXact();
-	ResourceOwnerRelease(TopTransactionResourceOwner,
-						 RESOURCE_RELEASE_LOCKS,
-						 false, true);
-	ResourceOwnerRelease(TopTransactionResourceOwner,
-						 RESOURCE_RELEASE_AFTER_LOCKS,
-						 false, true);
-	AtEOXact_CatCache(false);
-
-	AtEOXact_GUC(false, 1);
-	AtEOXact_SPI(false);
-	AtEOXact_on_commit_actions(false);
-	AtEOXact_Namespace(false);
-	smgrabort();
-	AtEOXact_Files();
-	AtEOXact_HashTables(false);
-	pgstat_count_xact_rollback();
+		AtEOXact_GUC(false, 1);
+		AtEOXact_SPI(false);
+		AtEOXact_on_commit_actions(false);
+		AtEOXact_Namespace(false);
+		smgrabort();
+		AtEOXact_Files();
+		AtEOXact_HashTables(false);
+		pgstat_count_xact_rollback();
+	}
 
 	/*
 	 * State remains TRANS_ABORT until CleanupTransaction().
diff --git a/src/backend/commands/trigger.c b/src/backend/commands/trigger.c
index 5c97e5feabe..b82125eb337 100644
--- a/src/backend/commands/trigger.c
+++ b/src/backend/commands/trigger.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.195.2.7 2009/10/27 20:14:56 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.195.2.8 2010/01/24 21:49:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2742,10 +2742,9 @@ AfterTriggerEndSubXact(bool isCommit)
 	/*
 	 * Pop the prior state if needed.
 	 */
-	Assert(my_level < afterTriggers->maxtransdepth);
-
 	if (isCommit)
 	{
+		Assert(my_level < afterTriggers->maxtransdepth);
 		/* If we saved a prior state, we don't need it anymore */
 		state = afterTriggers->state_stack[my_level];
 		if (state != NULL)
@@ -2758,7 +2757,15 @@ AfterTriggerEndSubXact(bool isCommit)
 	else
 	{
 		/*
-		 * Aborting --- restore the pointers from the stacks.
+		 * Aborting.  It is possible subxact start failed before calling
+		 * AfterTriggerBeginSubXact, in which case we mustn't risk touching
+		 * stack levels that aren't there.
+		 */
+		if (my_level >= afterTriggers->maxtransdepth)
+			return;
+
+		/*
+		 * Restore the pointers from the stacks.
 		 */
 		afterTriggers->events = afterTriggers->events_stack[my_level];
 		afterTriggers->query_depth = afterTriggers->depth_stack[my_level];
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 751e7921512..ed734975854 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.299.2.6 2009/12/09 21:58:43 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.299.2.7 2010/01/24 21:49:58 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -3109,7 +3109,14 @@ AtEOXact_GUC(bool isCommit, int nestLevel)
 {
 	int			i;
 
-	Assert(nestLevel > 0 && nestLevel <= GUCNestLevel);
+	/*
+	 * Note: it's possible to get here with GUCNestLevel == nestLevel-1 during
+	 * abort, if there is a failure during transaction start before
+	 * AtStart_GUC is called.
+	 */
+	Assert(nestLevel > 0 &&
+		   (nestLevel <= GUCNestLevel ||
+			(nestLevel == GUCNestLevel + 1 && !isCommit)));
 
 	/* Quick exit if nothing's changed in this transaction */
 	if (!guc_dirty)