Self review of previous patch. Fix assumption that xmax >= xmin.

simonat2ndQuadrant · simonat2ndQuadrant · commit 9975c683b102 · 2010-12-09T10:20:49.000Z
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
@@ -3809,11 +3809,9 @@ HeapTupleHeaderAdvanceLatestRemovedXid(HeapTupleHeader tuple,
 		 !(tuple->t_infomask & HEAP_XMIN_INVALID) &&
 		 TransactionIdDidCommit(xmin)))
 	{
-		if (TransactionIdFollows(xmax, xmin))
-		{
-			if (TransactionIdFollows(xmax, *latestRemovedXid))
+		if (xmax != xmin &&
+			TransactionIdFollows(xmax, *latestRemovedXid))
 				*latestRemovedXid = xmax;
-		}
 	}
 
 	/* *latestRemovedXid may still be invalid at end */

Original file line number	Diff line number	Diff line change
`@@ -3809,11 +3809,9 @@ HeapTupleHeaderAdvanceLatestRemovedXid(HeapTupleHeader tuple,`
`3809`	`3809`	`!(tuple->t_infomask & HEAP_XMIN_INVALID) &&`
`3810`	`3810`	`TransactionIdDidCommit(xmin)))`
`3811`	`3811`	`{`
`3812`		`- if (TransactionIdFollows(xmax, xmin))`
`3813`		`- {`
`3814`		`- if (TransactionIdFollows(xmax, *latestRemovedXid))`
	`3812`	`+ if (xmax != xmin &&`
	`3813`	`+ TransactionIdFollows(xmax, *latestRemovedXid))`
`3815`	`3814`	`*latestRemovedXid = xmax;`
`3816`		`- }`
`3817`	`3815`	`}`
`3818`	`3816`
`3819`	`3817`	`/* latestRemovedXid may still be invalid at end /`