Keep compiler quiet. Noted when compiling in FreeBSD in which i

get a warning for an uninitialized variable.

Also, define InvalidXLogRecPtr. We don't really need it but using
it make the initialization future proof (considering that in 9.3
XLogRecPtr will change its structure).

repmgrd.c

@@ -35,6 +35,15 @@
 #include "access/xlogdefs.h"
 #include "libpq/pqsignal.h"
 
+/* 
+ * we do not export InvalidXLogRecPtr so we need to define it 
+ * but since 9.3 it will be defined in xlogdefs.h which we include
+ * so better to ask if it's defined to be future proof
+ */
+#ifndef InvalidXLogRecPtr 
+const XLogRecPtr InvalidXLogRecPtr = {0, 0};
+#endif
+
 /*
  * Struct to keep info about the nodes, used in the voting process in
  * do_failover()
@@ -582,7 +591,8 @@ do_failover(void)
 	 * which seems to be large enough for most scenarios
 	 */
 	nodeInfo nodes[50];
-	nodeInfo best_candidate;
+	/* initialize to keep compiler quiet */
+	nodeInfo best_candidate = {-1, InvalidXLogRecPtr, false };
 
 	/* first we get info about this node, and update shared memory */
 	sprintf(sqlquery, "SELECT pg_last_xlog_replay_location()");