Bug#39338: Fieldnames in INFORMATIONSCHEMA.PARTITIONS.PARTITION_EXPRESSION

become unescaped

Problem was only with the print out of the KEY partitioning list of
fields, it did not include quotes, even if it was needed.

Fixed by always add quotes if needed.

mysql-test/r/partition.result

 drop table if exists t1, t2;
 CREATE TABLE t1 (
+ID int(11) NOT NULL,
+`aaaa,aaaaa` tinyint(3) UNSIGNED NOT NULL DEFAULT '0',
+ddddddddd int(11) NOT NULL DEFAULT '0',
+new_field0 varchar(50),
+PRIMARY KEY(ID, `aaaa,aaaaa`, ddddddddd))
+PARTITION BY RANGE(ID)
+PARTITIONS 3
+SUBPARTITION BY LINEAR KEY(ID,`aaaa,aaaaa`)
+SUBPARTITIONS 2 (
+PARTITION p01 VALUES LESS THAN(100),
+PARTITION p11 VALUES LESS THAN(200),
+PARTITION p21 VALUES LESS THAN MAXVALUE);
+SELECT PARTITION_EXPRESSION, SUBPARTITION_EXPRESSION FROM INFORMATION_SCHEMA.PARTITIONS WHERE TABLE_NAME='t1';
+PARTITION_EXPRESSION	SUBPARTITION_EXPRESSION
+ID	`ID`,`aaaa,aaaaa`
+ID	`ID`,`aaaa,aaaaa`
+ID	`ID`,`aaaa,aaaaa`
+ID	`ID`,`aaaa,aaaaa`
+ID	`ID`,`aaaa,aaaaa`
+ID	`ID`,`aaaa,aaaaa`
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `ID` int(11) NOT NULL,
+  `aaaa,aaaaa` tinyint(3) unsigned NOT NULL DEFAULT '0',
+  `ddddddddd` int(11) NOT NULL DEFAULT '0',
+  `new_field0` varchar(50) DEFAULT NULL,
+  PRIMARY KEY (`ID`,`aaaa,aaaaa`,`ddddddddd`)
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+/*!50100 PARTITION BY RANGE (ID)
+SUBPARTITION BY LINEAR KEY (ID,`aaaa,aaaaa`)
+SUBPARTITIONS 2
+(PARTITION p01 VALUES LESS THAN (100) ENGINE = MyISAM,
+ PARTITION p11 VALUES LESS THAN (200) ENGINE = MyISAM,
+ PARTITION p21 VALUES LESS THAN MAXVALUE ENGINE = MyISAM) */
+drop table t1;
+CREATE TABLE t1 (
 pk INT NOT NULL AUTO_INCREMENT,
 PRIMARY KEY (pk)
 )

mysql-test/t/partition.test

@@ -14,6 +14,29 @@
 drop table if exists t1, t2;
 --enable_warnings
 
+#
+# Bug#39338: Fieldnames in INFORMATIONSCHEMA.PARTITIONS.PARTITION_EXPRESSION
+#            become unescaped
+# NOTE: the partition expression is saved as a string, so changing from
+#       normal quotes to ansi quotes does not change the expression, only
+#       for partition by KEY.
+CREATE TABLE t1 (
+    ID int(11) NOT NULL,
+    `aaaa,aaaaa` tinyint(3) UNSIGNED NOT NULL DEFAULT '0',
+    ddddddddd int(11) NOT NULL DEFAULT '0',
+    new_field0 varchar(50),
+    PRIMARY KEY(ID, `aaaa,aaaaa`, ddddddddd))
+PARTITION BY RANGE(ID)
+PARTITIONS 3
+SUBPARTITION BY LINEAR KEY(ID,`aaaa,aaaaa`)
+SUBPARTITIONS 2 (
+    PARTITION p01 VALUES LESS THAN(100),
+    PARTITION p11 VALUES LESS THAN(200),
+    PARTITION p21 VALUES LESS THAN MAXVALUE);
+SELECT PARTITION_EXPRESSION, SUBPARTITION_EXPRESSION FROM INFORMATION_SCHEMA.PARTITIONS WHERE TABLE_NAME='t1';
+show create table t1;
+drop table t1;
+
 #
 # Bug#40954: Crash if range search and order by.
 #

sql/sql_show.cc

@@ -4743,7 +4743,8 @@ static int get_schema_key_column_usage_record(THD *thd,
 
 
 #ifdef WITH_PARTITION_STORAGE_ENGINE
-static void collect_partition_expr(List<char> &field_list, String *str)
+static void collect_partition_expr(THD *thd, List<char> &field_list,
+                                   String *str)
 {
   List_iterator<char> part_it(field_list);
   ulong no_fields= field_list.elements;
@@ -4751,7 +4752,7 @@ static void collect_partition_expr(List<char> &field_list, String *str)
   str->length(0);
   while ((field_str= part_it++))
   {
-    str->append(field_str);
+    append_identifier(thd, str, field_str, strlen(field_str));
     if (--no_fields != 0)
       str->append(",");
   }
@@ -4915,7 +4916,7 @@ static int get_schema_partitions_record(THD *thd, TABLE_LIST *tables,
     }
     else if (part_info->list_of_part_fields)
     {
-      collect_partition_expr(part_info->part_field_list, &tmp_str);
+      collect_partition_expr(thd, part_info->part_field_list, &tmp_str);
       table->field[9]->store(tmp_str.ptr(), tmp_str.length(), cs);
     }
     table->field[9]->set_notnull();
@@ -4944,7 +4945,7 @@ static int get_schema_partitions_record(THD *thd, TABLE_LIST *tables,
       }
       else if (part_info->list_of_subpart_fields)
       {
-        collect_partition_expr(part_info->subpart_field_list, &tmp_str);
+        collect_partition_expr(thd, part_info->subpart_field_list, &tmp_str);
         table->field[10]->store(tmp_str.ptr(), tmp_str.length(), cs);
       }
       table->field[10]->set_notnull();