From 9305953bd2429cc021d15db1c8f72ba1fdc2c6bd Mon Sep 17 00:00:00 2001
From: Ian Barwick <barwick@gmail.com>
Date: Thu, 14 Feb 2019 15:52:40 +0900
Subject: [PATCH] Fix history file parsing

Also add additional debugging output.
---
 dbutils.c       | 58 +++++++++++++++++++++++++++++++++++++++----------
 repmgr-client.c | 10 +++++++++
 2 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/dbutils.c b/dbutils.c
index f70d2b70..c1242e4f 100644
--- a/dbutils.c
+++ b/dbutils.c
@@ -1521,11 +1521,13 @@ get_timeline_history(PGconn *repl_conn, TimeLineID tli)
 	PQExpBufferData query;
 	PGresult   *res = NULL;
 
-	int			nfields;
-	TimeLineID	file_tli;
+	PQExpBufferData result;
+	char		*resptr;
+
+	TimeLineHistoryEntry *history;
+	TimeLineID	file_tli = UNKNOWN_TIMELINE_ID;
 	uint32		switchpoint_hi;
 	uint32		switchpoint_lo;
-	TimeLineHistoryEntry *history;
 
 	initPQExpBuffer(&query);
 
@@ -1555,19 +1557,51 @@ get_timeline_history(PGconn *repl_conn, TimeLineID tli)
 		return NULL;
 	}
 
-	nfields = sscanf(PQgetvalue(res, 0, 1),
-					 "%u\t%X/%X",
-					 &file_tli, &switchpoint_hi, &switchpoint_lo);
+	initPQExpBuffer(&result);
+	appendPQExpBufferStr(&result, PQgetvalue(res, 0, 1));
+	PQclear(res);
 
-	if (nfields != 3)
+	resptr = result.data;
+
+	while (*resptr)
 	{
-		log_error(_("unable to parse timeline history file content"));
-		log_detail(_("content is: \"%s\""), PQgetvalue(res, 0, 1));
-		PQclear(res);
-		return NULL;
+		char	buf[MAXLEN];
+		char   *bufptr = buf;
+
+		if (*resptr != '\n')
+		{
+			int		len  = 0;
+
+			memset(buf, 0, MAXLEN);
+
+			while (*resptr && *resptr != '\n' && len < MAXLEN)
+			{
+				*bufptr++ = *resptr++;
+				len++;
+			}
+
+			if (buf[0])
+			{
+				int nfields = sscanf(buf,
+									 "%u\t%X/%X",
+									 &file_tli, &switchpoint_hi, &switchpoint_lo);
+				if (nfields == 3 && file_tli == tli - 1)
+					break;
+			}
+		}
+
+		if (*resptr)
+			resptr++;
 	}
 
-	PQclear(res);
+	termPQExpBuffer(&result);
+
+	if (file_tli == UNKNOWN_TIMELINE_ID || file_tli != tli - 1)
+	{
+		log_error(_("timeline %i not found in timeline history file content"), tli);
+		log_detail(_("content is: \"%s\""), result.data);
+		return NULL;
+	}
 
 	history = (TimeLineHistoryEntry *) palloc(sizeof(TimeLineHistoryEntry));
 	history->tli = file_tli;
diff --git a/repmgr-client.c b/repmgr-client.c
index 814dcdea..1f895f8a 100644
--- a/repmgr-client.c
+++ b/repmgr-client.c
@@ -3380,6 +3380,12 @@ check_node_can_attach(TimeLineID local_tli, XLogRecPtr local_xlogpos, PGconn *fo
 			return false;
 		}
 
+		log_debug("local tli: %i; local_xlogpos: %X/%X; follow_target_history->tli: %i; follow_target_history->end: %X/%X",
+				  local_tli,
+				  format_lsn(local_xlogpos),
+				  follow_target_history->tli,
+				  format_lsn(follow_target_history->end));
+
 		/*
 		 * Local node has proceeded beyond the follow target's fork, so we
 		 * definitely can't attach.
@@ -3432,6 +3438,10 @@ check_node_can_attach(TimeLineID local_tli, XLogRecPtr local_xlogpos, PGconn *fo
 	}
 
 	PQfinish(follow_target_repl_conn);
+
+	if (follow_target_history)
+		pfree(follow_target_history);
+
 	return success;
 }