Add cross-check that current timeline of pg_control is an ancestor of

recovery_target_timeline --- otherwise there is no path from the backup
to the requested timeline.  This check was foreseen in the original
discussion but I forgot to implement it.

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 54a71b8..f9a4933 100644 (file)
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.151 2004/07/22 20:18:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/access/transam/xlog.c,v 1.152 2004/07/22 21:09:37 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -4009,6 +4009,18 @@ StartupXLOG(void)
        expectedTLIs = readTimeLineHistory(recoveryTargetTLI);
 
        /*
+        * If pg_control's timeline is not in expectedTLIs, then we cannot
+        * proceed: the backup is not part of the history of the requested
+        * timeline.
+        */
+       if (!list_member_int(expectedTLIs,
+                                                (int) ControlFile->checkPointCopy.ThisTimeLineID))
+               ereport(FATAL,
+                               (errmsg("requested timeline %u is not a child of database system timeline %u",
+                                               recoveryTargetTLI,
+                                               ControlFile->checkPointCopy.ThisTimeLineID)));
+
+       /*
         * Get the last valid checkpoint record.  If the latest one according
         * to pg_control is broken, try the next-to-last one.
         */