Bug#50201: Server crashes in explain_filename on an InnoDB partitioned table

Problem was that in mysql-trunk the ER() macro is now dependent on current_thd
and the innodb monitor thread has no binding to that thd object. This cause 
the crash because of bad derefencing.

Solution was to add a new macro which take the thd as an argument (which the innodb
thread uses for the call).

(Updated according to reviewers comments, i.e. added ER_THD_OR_DEFAULT and
moved test to suite parts.)

mysql-test/suite/parts/r/partition_innodb_status_file.result

+CREATE TABLE t1 (a INT) ENGINE = InnoDB PARTITION BY HASH(a);
+INSERT INTO t1 VALUES (0), (1), (2);
+START TRANSACTION;
+UPDATE t1 SET a = 5 WHERE a = 1;
+# Connection con1
+# InnoDB lock timeout and monitor thread runs every 15 seconds
+SET innodb_lock_wait_timeout = 20;
+START TRANSACTION;
+UPDATE t1 SET a = 3 WHERE a = 1;
+ERROR HY000: Lock wait timeout exceeded; try restarting transaction
+COMMIT;
+# Connection default
+COMMIT;
+DROP TABLE t1;

mysql-test/suite/parts/t/partition_innodb_status_file-master.opt

+--innodb-status-file=1

mysql-test/suite/parts/t/partition_innodb_status_file.test

+--source include/have_innodb.inc
+--source include/have_partition.inc
+
+CREATE TABLE t1 (a INT) ENGINE = InnoDB PARTITION BY HASH(a);
+INSERT INTO t1 VALUES (0), (1), (2);
+START TRANSACTION;
+UPDATE t1 SET a = 5 WHERE a = 1;
+connect (con1, localhost, root,,);
+--echo # Connection con1
+--echo # InnoDB lock timeout and monitor thread runs every 15 seconds
+SET innodb_lock_wait_timeout = 20;
+START TRANSACTION;
+--error ER_LOCK_WAIT_TIMEOUT
+UPDATE t1 SET a = 3 WHERE a = 1;
+COMMIT;
+disconnect con1;
+connection default;
+--echo # Connection default
+COMMIT;
+DROP TABLE t1;

sql/sql_table.cc

@@ -291,7 +291,8 @@ uint explain_filename(THD* thd,
   {
     if (explain_mode == EXPLAIN_ALL_VERBOSE)
     {
-      to_p= strnmov(to_p, ER(ER_DATABASE_NAME), end_p - to_p);
+      to_p= strnmov(to_p, ER_THD_OR_DEFAULT(thd, ER_DATABASE_NAME),
+                                            end_p - to_p);
       *(to_p++)= ' ';
       to_p= add_identifier(thd, to_p, end_p, db_name, db_name_len);
       to_p= strnmov(to_p, ", ", end_p - to_p);
@@ -304,7 +305,7 @@ uint explain_filename(THD* thd,
   }
   if (explain_mode == EXPLAIN_ALL_VERBOSE)
   {
-    to_p= strnmov(to_p, ER(ER_TABLE_NAME), end_p - to_p);
+    to_p= strnmov(to_p, ER_THD_OR_DEFAULT(thd, ER_TABLE_NAME), end_p - to_p);
     *(to_p++)= ' ';
     to_p= add_identifier(thd, to_p, end_p, table_name, table_name_len);
   }
@@ -321,18 +322,22 @@ uint explain_filename(THD* thd,
     if (name_type != NORMAL)
     {
       if (name_type == TEMP)
-        to_p= strnmov(to_p, ER(ER_TEMPORARY_NAME), end_p - to_p);
+        to_p= strnmov(to_p, ER_THD_OR_DEFAULT(thd, ER_TEMPORARY_NAME),
+                      end_p - to_p);
       else
-        to_p= strnmov(to_p, ER(ER_RENAMED_NAME), end_p - to_p);
+        to_p= strnmov(to_p, ER_THD_OR_DEFAULT(thd, ER_RENAMED_NAME),
+                      end_p - to_p);
       to_p= strnmov(to_p, " ", end_p - to_p);
     }
-    to_p= strnmov(to_p, ER(ER_PARTITION_NAME), end_p - to_p);
+    to_p= strnmov(to_p, ER_THD_OR_DEFAULT(thd, ER_PARTITION_NAME),
+                  end_p - to_p);
     *(to_p++)= ' ';
     to_p= add_identifier(thd, to_p, end_p, part_name, part_name_len);
     if (subpart_name)
     {
       to_p= strnmov(to_p, ", ", end_p - to_p);
-      to_p= strnmov(to_p, ER(ER_SUBPARTITION_NAME), end_p - to_p);
+      to_p= strnmov(to_p, ER_THD_OR_DEFAULT(thd, ER_SUBPARTITION_NAME),
+                    end_p - to_p);
       *(to_p++)= ' ';
       to_p= add_identifier(thd, to_p, end_p, subpart_name, subpart_name_len);
     }

sql/unireg.h

@@ -46,6 +46,9 @@
 #define ER(X)         CURRENT_THD_ERRMSGS[(X) - ER_ERROR_FIRST]
 #define ER_DEFAULT(X) DEFAULT_ERRMSGS[(X) - ER_ERROR_FIRST]
 #define ER_SAFE(X) (((X) >= ER_ERROR_FIRST && (X) <= ER_ERROR_LAST) ? ER(X) : "Invalid error code")
+#define ER_THD(thd,X) ((thd)->variables.lc_messages->errmsgs->errmsgs[(X) - \
+                       ER_ERROR_FIRST])
+#define ER_THD_OR_DEFAULT(thd,X) ((thd) ? ER_THD(thd, X) : ER_DEFAULT(X))
 
 
 #define ERRMAPP 1				/* Errormap f|r my_error */