fix-error-handling-xlogreader.patch

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 70cfabc..e33bd7a 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -3209,12 +3209,6 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
 		EndRecPtr = xlogreader->EndRecPtr;
 		if (record == NULL)
 		{
-			/* not all failures fill errormsg; report those that do */
-			if (errormsg && errormsg[0] != '\0')
-				ereport(emode_for_corrupt_record(emode,
-												 RecPtr ? RecPtr : EndRecPtr),
-						(errmsg_internal("%s", errormsg) /* already translated */));
-
 			lastSourceFailed = true;
 
 			if (readFile >= 0)
@@ -3222,7 +3216,23 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
 				close(readFile);
 				readFile = -1;
 			}
-			break;
+
+			/*
+			 * We only end up here without a message when XLogPageRead() failed
+			 * - in that case we already logged something.
+			 * In StandbyMode that only happens if we have been triggered, so
+			 * we shouldn't loop anymore in that case.
+			 */
+			if (errormsg == NULL)
+				break;
+
+
+			ereport(emode_for_corrupt_record(emode,
+											 RecPtr ? RecPtr : EndRecPtr),
+					(errmsg_internal("%s", errormsg) /* already translated */));
+
+			/* don't make a timeline check */
+			continue;
 		}
 
 		/*
@@ -3234,6 +3244,8 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
 			XLogSegNo segno;
 			int32 offset;
 
+			lastSourceFailed = true;
+
 			XLByteToSeg(xlogreader->latestPagePtr, segno);
 			offset = xlogreader->latestPagePtr % XLogSegSize;
 			XLogFileName(fname, xlogreader->readPageTLI, segno);
@@ -3243,7 +3255,7 @@ ReadRecord(XLogReaderState *xlogreader, XLogRecPtr RecPtr, int emode,
 							xlogreader->latestPageTLI,
 							fname,
 							offset)));
-			return false;
+			continue;
 		}
 	} while (StandbyMode && record == NULL);
 
diff --git a/src/backend/access/transam/xlogreader.c b/src/backend/access/transam/xlogreader.c
index ff871a3..75164f6 100644
--- a/src/backend/access/transam/xlogreader.c
+++ b/src/backend/access/transam/xlogreader.c
@@ -222,11 +222,7 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 	readOff = ReadPageInternal(state, targetPagePtr, SizeOfXLogRecord);
 
 	if (readOff < 0)
-	{
-		if (state->errormsg_buf[0] != '\0')
-			*errormsg = state->errormsg_buf;
-		return NULL;
-	}
+		goto err;
 
 	/*
 	 * ReadPageInternal always returns at least the page header, so we can
@@ -246,8 +242,7 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 	{
 		report_invalid_record(state, "invalid record offset at %X/%X",
 							  (uint32) (RecPtr >> 32), (uint32) RecPtr);
-		*errormsg = state->errormsg_buf;
-		return NULL;
+		goto err;
 	}
 
 	if ((((XLogPageHeader) state->readBuf)->xlp_info & XLP_FIRST_IS_CONTRECORD) &&
@@ -255,8 +250,7 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 	{
 		report_invalid_record(state, "contrecord is requested by %X/%X",
 							  (uint32) (RecPtr >> 32), (uint32) RecPtr);
-		*errormsg = state->errormsg_buf;
-		return NULL;
+		goto err;
 	}
 
 	/* ReadPageInternal has verified the page header */
@@ -270,11 +264,7 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 							   targetPagePtr,
 						  Min(targetRecOff + SizeOfXLogRecord, XLOG_BLCKSZ));
 	if (readOff < 0)
-	{
-		if (state->errormsg_buf[0] != '\0')
-			*errormsg = state->errormsg_buf;
-		return NULL;
-	}
+		goto err;
 
 	/*
 	 * Read the record length.
@@ -300,11 +290,7 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 	{
 		if (!ValidXLogRecordHeader(state, RecPtr, state->ReadRecPtr, record,
 								   randAccess))
-		{
-			if (state->errormsg_buf[0] != '\0')
-				*errormsg = state->errormsg_buf;
-			return NULL;
-		}
+			goto err;
 		gotheader = true;
 	}
 	else
@@ -314,8 +300,7 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 		{
 			report_invalid_record(state, "invalid record length at %X/%X",
 								  (uint32) (RecPtr >> 32), (uint32) RecPtr);
-			*errormsg = state->errormsg_buf;
-			return NULL;
+			goto err;
 		}
 		gotheader = false;
 	}
@@ -330,8 +315,7 @@ XLogReadRecord(XLogReaderState *state, XLogRecPtr RecPtr, char **errormsg)
 		report_invalid_record(state, "record length %u at %X/%X too long",
 							  total_len,
 							  (uint32) (RecPtr >> 32), (uint32) RecPtr);
-		*errormsg = state->errormsg_buf;
-		return NULL;
+		goto err;
 	}
 
 	len = XLOG_BLCKSZ - RecPtr % XLOG_BLCKSZ;