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 7cfa169e9b98d2abf26f85fa34cae843eda624b8..3ed2a2e811e85645677e47d491b1a77fc314a426 100644 (file)
--- a/src/bin/pg_rewind/parsexlog.c
+++ b/src/bin/pg_rewind/parsexlog.c
@@ -102,7 +102,9 @@ 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",
+                LSN_FORMAT_ARGS(endpoint), LSN_FORMAT_ARGS(xlogreader->EndRecPtr));
 
    XLogReaderFree(xlogreader);
    if (xlogreadfd != -1)