pg_upgrade: Upgrade an Assert to a real 'if' test

It seems possible for the condition being tested to be true in
production, and nobody would never know (except when some data
eventually becomes corrupt?).

Author: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m//202109040001.zky3wgv2qeqg@alvherre.pgsql

diff --git a/src/bin/pg_rewind/parsexlog.c b/src/bin/pg_rewind/parsexlog.c
index eac58f5cf0ff0a1b9578b5065b63624394db34b2..c8fd4f0bac781aadf52628d34723dedd47fa83ea 100644 (file)
--- a/src/bin/pg_rewind/parsexlog.c
+++ b/src/bin/pg_rewind/parsexlog.c
@@ -105,7 +105,11 @@ extractPageMap(const char *datadir, XLogRecPtr startpoint, int tliIndex,
         * If 'endpoint' didn't point exactly at a record boundary, the caller
         * messed up.
         */
-       Assert(xlogreader->EndRecPtr == endpoint);
+       if (xlogreader->EndRecPtr != endpoint)
+               pg_fatal("end pointer %X/%X is not a valid end point; expected %X/%X",
+                                (uint32) (endpoint >> 32), (uint32) (endpoint),
+                                (uint32) (xlogreader->EndRecPtr >> 32), (uint32)
+                                (xlogreader->EndRecPtr));
 
        XLogReaderFree(xlogreader);
        if (xlogreadfd != -1)