Incorrect usage of GenericXLogRegisterBuffer

[knizhnik]

There are some places in RUM where GenericXLogRegisterBuffer is called for newly created by RumNewBuffer page without GENERIC_XLOG_FULL_IMAGE flag. For example rumbtree.c:543:

					rpage = GenericXLogRegisterBuffer(state, rbuffer, 0);

The problem is that RumNewBuffer doesn't initialize buffer, so it contains zeroes.
And XLogReadBufferExtended rejects new pages:

	if (mode == RBM_NORMAL)
	{
		/* check that page has been initialized */
		Page		page = (Page) BufferGetPage(buffer);

		/*
		 * We assume that PageIsNew is safe without a lock. During recovery,
		 * there should be no other backends that could modify the buffer at
		 * the same time.
		 */
		if (PageIsNew(page))
		{
			ReleaseBuffer(buffer);
			log_invalid_page(rlocator, forknum, blkno, true);
			return InvalidBuffer;
		}
	}

So in some cases recovery of RUM pages is not performed.

[knizhnik]

Suggested patch:

diff --git a/src/rumbtree.c b/src/rumbtree.c
index d93ed46..12c3a7d 100644
--- a/src/rumbtree.c
+++ b/src/rumbtree.c
@@ -540,7 +540,7 @@ rumInsertValue(Relation index, RumBtree btree, RumBtreeStack * stack,
                                        state = GenericXLogStart(index);
 
                                        lpage = GenericXLogRegisterBuffer(state, stack->buffer, 0);
-                                       rpage = GenericXLogRegisterBuffer(state, rbuffer, 0);
+                                       rpage = GenericXLogRegisterBuffer(state, rbuffer, GENERIC_XLOG_FULL_IMAGE);
                                }
 
                                rightrightBlkno = RumPageGetOpaque(lpage)->rightlink;