Fix for Bug#17888 DD: ADD INDEX causes error 756 'Index on disk column is not supported

mysql-test/r/ndb_dd_ddl.result

@@ -175,7 +175,7 @@ CREATE TABLE t1
 (pk1 INT NOT NULL PRIMARY KEY, b INT NOT NULL, c INT NOT NULL)
 TABLESPACE ts1 STORAGE DISK
 ENGINE NDB;
-CREATE INDEX c on t1(c);
+CREATE INDEX c on t1(b, c);
 DROP TABLE t1;
 ALTER TABLESPACE ts1
 DROP DATAFILE 'datafile2.dat'

mysql-test/t/ndb_dd_ddl.test

@@ -263,7 +263,7 @@ CREATE TABLE t1
 TABLESPACE ts1 STORAGE DISK
 ENGINE NDB;
 
-CREATE INDEX c on t1(c);
+CREATE INDEX c on t1(b, c);
 
 DROP TABLE t1;
 

sql/sql_table.cc

@@ -3706,6 +3706,8 @@ static uint compare_tables(TABLE *table, List<create_field> *create_list,
   uint changes= 0, tmp;
   List_iterator_fast<create_field> new_field_it(*create_list);
   create_field *new_field;
+  KEY_PART_INFO *key_part;
+  KEY_PART_INFO *end;
   DBUG_ENTER("compare_tables");
 
   /*
@@ -3833,9 +3835,14 @@ static uint compare_tables(TABLE *table, List<create_field> *create_list,
     /* Key modified. Add the offset of the key to both buffers. */
     index_drop_buffer[(*index_drop_count)++]= table_key - table->key_info;
     index_add_buffer[(*index_add_count)++]= new_key - key_info_buffer;
-    field= table->field[new_key->key_part->fieldnr];
-    // Mark field to be part of new key 
-    field->add_index= 1;
+    key_part= new_key->key_part;
+    end= key_part + new_key->key_parts;
+    for(; key_part != end; key_part++)
+    {
+      // Mark field to be part of new key 
+      field= table->field[key_part->fieldnr];
+      field->add_index= 1;
+    }
     DBUG_PRINT("info", ("index changed: '%s'", table_key->name));
   }
   /*end of for (; table_key < table_key_end;) */
@@ -3855,9 +3862,14 @@ static uint compare_tables(TABLE *table, List<create_field> *create_list,
     {
       /* Key not found. Add the offset of the key to the add buffer. */
       index_add_buffer[(*index_add_count)++]= new_key - key_info_buffer;
-      field= table->field[new_key->key_part->fieldnr];
-      // Mark field to be part of new key 
-      field->add_index= 1;
+      key_part= new_key->key_part;
+      end= key_part + new_key->key_parts;
+      for(; key_part != end; key_part++)
+      {
+        // Mark field to be part of new key 
+        field= table->field[key_part->fieldnr];
+        field->add_index= 1;
+      }
       DBUG_PRINT("info", ("index added: '%s'", new_key->name));
     }
   }