From 8caf6132c7498b2b9400a5496a29e48c1c0aa516 Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
Date: Mon, 12 Sep 2011 13:00:44 +0300
Subject: [PATCH] In the final emptying phase of the new GiST buffering build,
 set the queuedForEmptying flag correctly on buffer when adding it to the
 queue. Also, don't add buffer to the queue if it's there already. These were
 harmless oversights; failing to set the flag just means that a buffer might
 get added to the queue twice if more tuples are added to it (although that
 can't actually happen at this point because all the upper buffers have
 already been emptied), and having the same buffer twice in the emptying queue
 is harmless. But better be tidy.

---
 src/backend/access/gist/gistbuild.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c
index 58f1ef221e1..0046c7b3ab3 100644
--- a/src/backend/access/gist/gistbuild.c
+++ b/src/backend/access/gist/gistbuild.c
@@ -964,10 +964,14 @@ gistEmptyAllBuffers(GISTBuildState *buildstate)
 				 * Add this buffer to the emptying queue, and proceed to empty
 				 * the queue.
 				 */
-				MemoryContextSwitchTo(gfbb->context);
-				gfbb->bufferEmptyingQueue =
-					lcons(nodeBuffer, gfbb->bufferEmptyingQueue);
-				MemoryContextSwitchTo(buildstate->tmpCtx);
+				if (!nodeBuffer->queuedForEmptying)
+				{
+					MemoryContextSwitchTo(gfbb->context);
+					nodeBuffer->queuedForEmptying = true;
+					gfbb->bufferEmptyingQueue =
+						lcons(nodeBuffer, gfbb->bufferEmptyingQueue);
+					MemoryContextSwitchTo(buildstate->tmpCtx);
+				}
 				gistProcessEmptyingQueue(buildstate);
 			}
 			else
-- 
GitLab