Add some improved debugging to help understand non

locally reproducable problems with 
ndb_binlog_last_commit_epoch testcase.

No change to result file, except in error conditions.

Author: frazerclement

mysql-test/suite/ndb_binlog/t/ndb_binlog_cmp_epoch_vals.inc

@@ -9,23 +9,45 @@ select @curr_session_epoch:=Variable_value
 from information_schema.global_status 
 where Variable_name ="ndb_last_commit_epoch_session";
 
+# Wait for latest committed transaction to reach binlog
 show binlog events;
 
+--source include/get_ndb_epochs.inc
+
 select @binlog_max_epoch:= max(epoch) 
 from mysql.ndb_binlog_index;
 
 --enable_result_log
 
-select (@init_server_epoch + 0) >= (@init_session_epoch + 0) 
+select @a:= (@init_server_epoch + 0) >= (@init_session_epoch + 0) 
   as init_server_epoch_includes_session_epoch,
-  (@curr_server_epoch + 0) >= (@curr_session_epoch + 0) 
+  @b:= (@curr_server_epoch + 0) >= (@curr_session_epoch + 0) 
   as curr_server_epoch_includes_session_epoch,
-  (@curr_server_epoch + 0) >= (@init_server_epoch + 0) 
+  @c:= (@curr_server_epoch + 0) >= (@init_server_epoch + 0) 
   as server_epoch_does_not_regress,
-  (@curr_session_epoch + 0) >= (@init_session_epoch + 0) 
+  @d:= (@curr_session_epoch + 0) >= (@init_session_epoch + 0) 
   as session_epoch_does_not_regress;
 
-select @binlog_max_epoch = @curr_session_epoch as
+select (@binlog_max_epoch+0) = (@curr_session_epoch+0) as
   binlog_contains_last_session_epoch;
 
+--disable_result_log
+
+eval select @e:= (($ndb_latest_applied_binlog_epoch + 0) = @binlog_max_epoch);
+
+--let $problem=query_get_value("SELECT 5 - (@a+@b+@c+@d+@e) AS p", p, 1)
+
+--enable_result_log
+if ($problem)
+{
+  --echo Unexpected result.  Details : 
+
+  SELECT @init_server_epoch, @init_session_epoch,
+    @curr_server_epoch, @curr_session_epoch;
+
+  eval select $ndb_latest_applied_binlog_epoch as ndb_latest_applied_binlog_epoch, @binlog_max_epoch;
+
+  SELECT * FROM mysql.ndb_binlog_index;
+}
+
 --enable_query_log