Assert that pre/post-fix updated tuples are on the same page during replay.

hlinnaka · hlinnaka · commit 1460b199e6e7 · 2014-05-05T16:15:25.000+03:00
If they were not 'oldtup.t_data' would be dereferenced while set to NULL
in case of a full page image for block 0.

Do so primarily to silence coverity; but also to make sure this prerequisite
isn't changed without adapting the replay routine as that would appear to
work in many cases.

Andres Freund
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
@@ -8115,11 +8115,13 @@ newsame:;
 
 	if (xlrec->flags & XLOG_HEAP_PREFIX_FROM_OLD)
 	{
+		Assert(samepage);
 		memcpy(&prefixlen, recdata, sizeof(uint16));
 		recdata += sizeof(uint16);
 	}
 	if (xlrec->flags & XLOG_HEAP_SUFFIX_FROM_OLD)
 	{
+		Assert(samepage);
 		memcpy(&suffixlen, recdata, sizeof(uint16));
 		recdata += sizeof(uint16);
 	}

Original file line number	Diff line number	Diff line change
`@@ -8115,11 +8115,13 @@ newsame:;`
`8115`	`8115`
`8116`	`8116`	`if (xlrec->flags & XLOG_HEAP_PREFIX_FROM_OLD)`
`8117`	`8117`	`{`
	`8118`	`+ Assert(samepage);`
`8118`	`8119`	`memcpy(&prefixlen, recdata, sizeof(uint16));`
`8119`	`8120`	`recdata += sizeof(uint16);`
`8120`	`8121`	`}`
`8121`	`8122`	`if (xlrec->flags & XLOG_HEAP_SUFFIX_FROM_OLD)`
`8122`	`8123`	`{`
	`8124`	`+ Assert(samepage);`
`8123`	`8125`	`memcpy(&suffixlen, recdata, sizeof(uint16));`
`8124`	`8126`	`recdata += sizeof(uint16);`
`8125`	`8127`	`}`