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

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
index a04763207f031c517a45362c743d7ad329fe5890..336fbb06dac9cc481d4bf035eda21dd391953fd1 100644 (file)
--- 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);
    }