Bug#31434 mysqldump dumps view as table

mysqldump creates stand-in tables before dumping the actual view.
Those tables were of the default type; if the view had more columns
than that (a pathological case, arguably), loading the dump would
fail. We now make the temporary stand-ins MyISAM tables to prevent
this.

client/mysqldump.c

@@ -2396,8 +2396,15 @@ static uint get_table_structure(char *table, char *db, char *table_type,
             fprintf(sql_file, ",\n  %s %s",
                     quote_name(row[0], name_buff, 0), row[1]);
           }
+
+          /*
+            Stand-in tables are always MyISAM tables as the default
+            engine might have a column-limit that's lower than the
+            number of columns in the view, and MyISAM support is
+            guaranteed to be in the server anyway.
+          */
           fprintf(sql_file,
-                  "\n) */;\n"
+                  "\n) ENGINE=MyISAM */;\n"
                   "SET character_set_client = @saved_cs_client;\n");
 
           check_io(sql_file);

mysql-test/r/mysqldump-max.result

@@ -277,3 +277,16 @@ drop table t3;
 drop table t4;
 drop table t5;
 drop table t6;
+SELECT @@global.storage_engine INTO @old_engine;
+SET GLOBAL storage_engine=InnoDB;
+CREATE VIEW v1 AS SELECT * FROM t1;
+INSERT INTO t1 VALUES();
+SELECT COUNT(*) FROM v1;
+COUNT(*)
+1
+SELECT COUNT(*) FROM v1;
+COUNT(*)
+1
+DROP VIEW  v1;
+DROP TABLE t1;
+SET GLOBAL storage_engine=@old_engine;

mysql-test/r/mysqldump.result

@@ -1999,7 +1999,7 @@ SET @saved_cs_client     = @@character_set_client;
 SET character_set_client = utf8;
 /*!50001 CREATE TABLE `v2` (
   `a` varchar(30)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 /*!50001 DROP TABLE `v2`*/;
 /*!50001 DROP VIEW IF EXISTS `v2`*/;
@@ -2096,7 +2096,7 @@ SET @saved_cs_client     = @@character_set_client;
 SET character_set_client = utf8;
 /*!50001 CREATE TABLE `v1` (
   `a` int(11)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 /*!50001 DROP TABLE `v1`*/;
 /*!50001 DROP VIEW IF EXISTS `v1`*/;
@@ -2170,7 +2170,7 @@ SET @saved_cs_client     = @@character_set_client;
 SET character_set_client = utf8;
 /*!50001 CREATE TABLE `v2` (
   `a` varchar(30)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 /*!50001 DROP TABLE `v2`*/;
 /*!50001 DROP VIEW IF EXISTS `v2`*/;
@@ -2286,7 +2286,7 @@ SET character_set_client = utf8;
   `a` int(11),
   `b` int(11),
   `c` varchar(30)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 DROP TABLE IF EXISTS `v2`;
 /*!50001 DROP VIEW IF EXISTS `v2`*/;
@@ -2294,7 +2294,7 @@ SET @saved_cs_client     = @@character_set_client;
 SET character_set_client = utf8;
 /*!50001 CREATE TABLE `v2` (
   `a` int(11)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 DROP TABLE IF EXISTS `v3`;
 /*!50001 DROP VIEW IF EXISTS `v3`*/;
@@ -2304,7 +2304,7 @@ SET character_set_client = utf8;
   `a` int(11),
   `b` int(11),
   `c` varchar(30)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 /*!50001 DROP TABLE `v1`*/;
 /*!50001 DROP VIEW IF EXISTS `v1`*/;
@@ -3041,7 +3041,7 @@ SET character_set_client = utf8;
   `a` int(11),
   `b` varchar(32),
   `c` varchar(32)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 DROP TABLE IF EXISTS `v1`;
 /*!50001 DROP VIEW IF EXISTS `v1`*/;
@@ -3051,7 +3051,7 @@ SET character_set_client = utf8;
   `a` int(11),
   `b` varchar(32),
   `c` varchar(32)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 DROP TABLE IF EXISTS `v2`;
 /*!50001 DROP VIEW IF EXISTS `v2`*/;
@@ -3061,7 +3061,7 @@ SET character_set_client = utf8;
   `a` int(11),
   `b` varchar(32),
   `c` varchar(32)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 
 USE `test`;
@@ -3441,7 +3441,7 @@ SET @saved_cs_client     = @@character_set_client;
 SET character_set_client = utf8;
 /*!50001 CREATE TABLE `v1` (
   `id` int(11)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 
 USE `mysqldump_test_db`;
@@ -3501,7 +3501,7 @@ SET @saved_cs_client     = @@character_set_client;
 SET character_set_client = utf8;
 /*!50001 CREATE TABLE `nasishnasifu` (
   `id` bigint(20) unsigned
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 
 USE `mysqldump_tables`;
@@ -3959,7 +3959,7 @@ SET @saved_cs_client     = @@character_set_client;
 SET character_set_client = utf8;
 /*!50001 CREATE TABLE `v1` (
   `id` int(11)
-) */;
+) ENGINE=MyISAM */;
 SET character_set_client = @saved_cs_client;
 
 USE `mysqldump_test_db`;