Report any XLogReadRecord() error in XlogReadTwoPhaseData().

Buildfarm members kittiwake and tadarida have witnessed errors at this
site.  The site discarded key facts.  Back-patch to v10 (all supported
versions).

Reviewed by Michael Paquier and Tom Lane.

Discussion: https://postgr.es/m/20211107013157.GB790288@rfd.leadboat.com

diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index ef4b5f639ced42ee44b16b6db94f3a1593284aa4..28b153abc3c12cba3b3b4c883141fe0992a8d04b 100644 (file)
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1397,10 +1397,18 @@ XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
        record = XLogReadRecord(xlogreader, &errormsg);
 
        if (record == NULL)
-               ereport(ERROR,
-                               (errcode_for_file_access(),
-                                errmsg("could not read two-phase state from WAL at %X/%X",
-                                               LSN_FORMAT_ARGS(lsn))));
+       {
+               if (errormsg)
+                       ereport(ERROR,
+                                       (errcode_for_file_access(),
+                                        errmsg("could not read two-phase state from WAL at %X/%X: %s",
+                                                       LSN_FORMAT_ARGS(lsn), errormsg)));
+               else
+                       ereport(ERROR,
+                                       (errcode_for_file_access(),
+                                        errmsg("could not read two-phase state from WAL at %X/%X",
+                                                       LSN_FORMAT_ARGS(lsn))));
+       }
 
        if (XLogRecGetRmid(xlogreader) != RM_XACT_ID ||
                (XLogRecGetInfo(xlogreader) & XLOG_XACT_OPMASK) != XLOG_XACT_PREPARE)