Bug#31633 Information schema = NULL queries crash the server

added correct handling of NULL values for lookup fields

mysql-test/r/information_schema.result

@@ -1564,4 +1564,44 @@ SELECT TABLE_COLLATION FROM INFORMATION_SCHEMA.TABLES
 WHERE TABLE_SCHEMA='mysql' and TABLE_NAME= 'db';
 TABLE_COLLATION
 utf8_bin
+select * from information_schema.columns where table_schema = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	COLUMN_DEFAULT	IS_NULLABLE	DATA_TYPE	CHARACTER_MAXIMUM_LENGTH	CHARACTER_OCTET_LENGTH	NUMERIC_PRECISION	NUMERIC_SCALE	CHARACTER_SET_NAME	COLLATION_NAME	COLUMN_TYPE	COLUMN_KEY	EXTRA	PRIVILEGES	COLUMN_COMMENT
+select * from `information_schema`.`COLUMNS` where `TABLE_NAME` = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	COLUMN_DEFAULT	IS_NULLABLE	DATA_TYPE	CHARACTER_MAXIMUM_LENGTH	CHARACTER_OCTET_LENGTH	NUMERIC_PRECISION	NUMERIC_SCALE	CHARACTER_SET_NAME	COLLATION_NAME	COLUMN_TYPE	COLUMN_KEY	EXTRA	PRIVILEGES	COLUMN_COMMENT
+select * from `information_schema`.`KEY_COLUMN_USAGE` where `TABLE_SCHEMA` = NULL;
+CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	POSITION_IN_UNIQUE_CONSTRAINT	REFERENCED_TABLE_SCHEMA	REFERENCED_TABLE_NAME	REFERENCED_COLUMN_NAME
+select * from `information_schema`.`KEY_COLUMN_USAGE` where `TABLE_NAME` = NULL;
+CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	COLUMN_NAME	ORDINAL_POSITION	POSITION_IN_UNIQUE_CONSTRAINT	REFERENCED_TABLE_SCHEMA	REFERENCED_TABLE_NAME	REFERENCED_COLUMN_NAME
+select * from `information_schema`.`PARTITIONS` where `TABLE_SCHEMA` = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PARTITION_NAME	SUBPARTITION_NAME	PARTITION_ORDINAL_POSITION	SUBPARTITION_ORDINAL_POSITION	PARTITION_METHOD	SUBPARTITION_METHOD	PARTITION_EXPRESSION	SUBPARTITION_EXPRESSION	PARTITION_DESCRIPTION	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	CREATE_TIME	UPDATE_TIME	CHECK_TIME	CHECKSUM	PARTITION_COMMENT	NODEGROUP	TABLESPACE_NAME
+select * from `information_schema`.`PARTITIONS` where `TABLE_NAME` = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	PARTITION_NAME	SUBPARTITION_NAME	PARTITION_ORDINAL_POSITION	SUBPARTITION_ORDINAL_POSITION	PARTITION_METHOD	SUBPARTITION_METHOD	PARTITION_EXPRESSION	SUBPARTITION_EXPRESSION	PARTITION_DESCRIPTION	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	CREATE_TIME	UPDATE_TIME	CHECK_TIME	CHECKSUM	PARTITION_COMMENT	NODEGROUP	TABLESPACE_NAME
+select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `CONSTRAINT_SCHEMA` = NULL;
+CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	UNIQUE_CONSTRAINT_CATALOG	UNIQUE_CONSTRAINT_SCHEMA	UNIQUE_CONSTRAINT_NAME	MATCH_OPTION	UPDATE_RULE	DELETE_RULE	TABLE_NAME	REFERENCED_TABLE_NAME
+select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `TABLE_NAME` = NULL;
+CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	UNIQUE_CONSTRAINT_CATALOG	UNIQUE_CONSTRAINT_SCHEMA	UNIQUE_CONSTRAINT_NAME	MATCH_OPTION	UPDATE_RULE	DELETE_RULE	TABLE_NAME	REFERENCED_TABLE_NAME
+select * from information_schema.schemata where schema_name = NULL;
+CATALOG_NAME	SCHEMA_NAME	DEFAULT_CHARACTER_SET_NAME	DEFAULT_COLLATION_NAME	SQL_PATH
+select * from `information_schema`.`STATISTICS` where `TABLE_SCHEMA` = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	NON_UNIQUE	INDEX_SCHEMA	INDEX_NAME	SEQ_IN_INDEX	COLUMN_NAME	COLLATION	CARDINALITY	SUB_PART	PACKED	NULLABLE	INDEX_TYPE	COMMENT
+select * from `information_schema`.`STATISTICS` where `TABLE_NAME` = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	NON_UNIQUE	INDEX_SCHEMA	INDEX_NAME	SEQ_IN_INDEX	COLUMN_NAME	COLLATION	CARDINALITY	SUB_PART	PACKED	NULLABLE	INDEX_TYPE	COMMENT
+select * from information_schema.tables where table_schema = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	TABLE_TYPE	ENGINE	VERSION	ROW_FORMAT	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	AUTO_INCREMENT	CREATE_TIME	UPDATE_TIME	CHECK_TIME	TABLE_COLLATION	CHECKSUM	CREATE_OPTIONS	TABLE_COMMENT
+select * from information_schema.tables where table_catalog = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	TABLE_TYPE	ENGINE	VERSION	ROW_FORMAT	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	AUTO_INCREMENT	CREATE_TIME	UPDATE_TIME	CHECK_TIME	TABLE_COLLATION	CHECKSUM	CREATE_OPTIONS	TABLE_COMMENT
+select * from information_schema.tables where table_name = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	TABLE_TYPE	ENGINE	VERSION	ROW_FORMAT	TABLE_ROWS	AVG_ROW_LENGTH	DATA_LENGTH	MAX_DATA_LENGTH	INDEX_LENGTH	DATA_FREE	AUTO_INCREMENT	CREATE_TIME	UPDATE_TIME	CHECK_TIME	TABLE_COLLATION	CHECKSUM	CREATE_OPTIONS	TABLE_COMMENT
+select * from `information_schema`.`TABLE_CONSTRAINTS` where `TABLE_SCHEMA` = NULL;
+CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_SCHEMA	TABLE_NAME	CONSTRAINT_TYPE
+select * from `information_schema`.`TABLE_CONSTRAINTS` where `TABLE_NAME` = NULL;
+CONSTRAINT_CATALOG	CONSTRAINT_SCHEMA	CONSTRAINT_NAME	TABLE_SCHEMA	TABLE_NAME	CONSTRAINT_TYPE
+select * from `information_schema`.`TRIGGERS` where `EVENT_OBJECT_SCHEMA` = NULL;
+TRIGGER_CATALOG	TRIGGER_SCHEMA	TRIGGER_NAME	EVENT_MANIPULATION	EVENT_OBJECT_CATALOG	EVENT_OBJECT_SCHEMA	EVENT_OBJECT_TABLE	ACTION_ORDER	ACTION_CONDITION	ACTION_STATEMENT	ACTION_ORIENTATION	ACTION_TIMING	ACTION_REFERENCE_OLD_TABLE	ACTION_REFERENCE_NEW_TABLE	ACTION_REFERENCE_OLD_ROW	ACTION_REFERENCE_NEW_ROW	CREATED	SQL_MODE	DEFINER	CHARACTER_SET_CLIENT	COLLATION_CONNECTION	DATABASE_COLLATION
+select * from `information_schema`.`TRIGGERS` where `EVENT_OBJECT_TABLE` = NULL;
+TRIGGER_CATALOG	TRIGGER_SCHEMA	TRIGGER_NAME	EVENT_MANIPULATION	EVENT_OBJECT_CATALOG	EVENT_OBJECT_SCHEMA	EVENT_OBJECT_TABLE	ACTION_ORDER	ACTION_CONDITION	ACTION_STATEMENT	ACTION_ORIENTATION	ACTION_TIMING	ACTION_REFERENCE_OLD_TABLE	ACTION_REFERENCE_NEW_TABLE	ACTION_REFERENCE_OLD_ROW	ACTION_REFERENCE_NEW_ROW	CREATED	SQL_MODE	DEFINER	CHARACTER_SET_CLIENT	COLLATION_CONNECTION	DATABASE_COLLATION
+select * from `information_schema`.`VIEWS` where `TABLE_SCHEMA` = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	VIEW_DEFINITION	CHECK_OPTION	IS_UPDATABLE	DEFINER	SECURITY_TYPE	CHARACTER_SET_CLIENT	COLLATION_CONNECTION
+select * from `information_schema`.`VIEWS` where `TABLE_NAME` = NULL;
+TABLE_CATALOG	TABLE_SCHEMA	TABLE_NAME	VIEW_DEFINITION	CHECK_OPTION	IS_UPDATABLE	DEFINER	SECURITY_TYPE	CHARACTER_SET_CLIENT	COLLATION_CONNECTION
 End of 5.1 tests.

mysql-test/t/information_schema.test

@@ -1208,4 +1208,28 @@ WHERE SCHEMA_NAME ='information_schema';
 SELECT TABLE_COLLATION FROM INFORMATION_SCHEMA.TABLES
 WHERE TABLE_SCHEMA='mysql' and TABLE_NAME= 'db';
 
+#
+# Bug#31633 Information schema = NULL queries crash the server
+#
+select * from information_schema.columns where table_schema = NULL;
+select * from `information_schema`.`COLUMNS` where `TABLE_NAME` = NULL;
+select * from `information_schema`.`KEY_COLUMN_USAGE` where `TABLE_SCHEMA` = NULL;
+select * from `information_schema`.`KEY_COLUMN_USAGE` where `TABLE_NAME` = NULL;
+select * from `information_schema`.`PARTITIONS` where `TABLE_SCHEMA` = NULL;
+select * from `information_schema`.`PARTITIONS` where `TABLE_NAME` = NULL;
+select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `CONSTRAINT_SCHEMA` = NULL;
+select * from `information_schema`.`REFERENTIAL_CONSTRAINTS` where `TABLE_NAME` = NULL;
+select * from information_schema.schemata where schema_name = NULL;
+select * from `information_schema`.`STATISTICS` where `TABLE_SCHEMA` = NULL;
+select * from `information_schema`.`STATISTICS` where `TABLE_NAME` = NULL;
+select * from information_schema.tables where table_schema = NULL;
+select * from information_schema.tables where table_catalog = NULL;
+select * from information_schema.tables where table_name = NULL;
+select * from `information_schema`.`TABLE_CONSTRAINTS` where `TABLE_SCHEMA` = NULL;
+select * from `information_schema`.`TABLE_CONSTRAINTS` where `TABLE_NAME` = NULL;
+select * from `information_schema`.`TRIGGERS` where `EVENT_OBJECT_SCHEMA` = NULL;
+select * from `information_schema`.`TRIGGERS` where `EVENT_OBJECT_TABLE` = NULL;
+select * from `information_schema`.`VIEWS` where `TABLE_SCHEMA` = NULL;
+select * from `information_schema`.`VIEWS` where `TABLE_NAME` = NULL;
+
 --echo End of 5.1 tests.

sql/sql_show.cc

@@ -2269,10 +2269,12 @@ int make_table_list(THD *thd, SELECT_LEX *sel,
   @param[in]      table                 I_S table
   @param[in, out] lookup_field_vals     Struct which holds lookup values 
 
-  @return         void
+  @return
+    0             success
+    1             error, there can be no matching records for the condition
 */
 
-void get_lookup_value(THD *thd, Item_func *item_func,
+bool get_lookup_value(THD *thd, Item_func *item_func,
                       TABLE_LIST *table, 
                       LOOKUP_FIELD_VALUES *lookup_field_vals)
 {
@@ -2305,13 +2307,17 @@ void get_lookup_value(THD *thd, Item_func *item_func,
       idx_val= 0;
     }
     else
-      return;
+      return 0;
 
     item_field= (Item_field*) item_func->arguments()[idx_field];
     if (table->table != item_field->field->table)
-      return;
+      return 0;
     tmp_str= item_func->arguments()[idx_val]->val_str(&str_buff);
 
+    /* impossible value */
+    if (!tmp_str)
+      return 1;
+
     /* Lookup value is database name */
     if (!cs->coll->strnncollsp(cs, (uchar *) field_name1, strlen(field_name1),
                                (uchar *) item_field->field_name,
@@ -2330,7 +2336,7 @@ void get_lookup_value(THD *thd, Item_func *item_func,
                            tmp_str->length(), FALSE);
     }
   }
-  return;
+  return 0;
 }
 
 
@@ -2346,14 +2352,16 @@ void get_lookup_value(THD *thd, Item_func *item_func,
   @param[in]      table                 I_S table
   @param[in, out] lookup_field_vals     Struct which holds lookup values 
 
-  @return         void
+  @return
+    0             success
+    1             error, there can be no matching records for the condition
 */
 
-void calc_lookup_values_from_cond(THD *thd, COND *cond, TABLE_LIST *table,
+bool calc_lookup_values_from_cond(THD *thd, COND *cond, TABLE_LIST *table,
                                   LOOKUP_FIELD_VALUES *lookup_field_vals)
 {
   if (!cond)
-    return;
+    return 0;
 
   if (cond->type() == Item::COND_ITEM)
   {
@@ -2364,16 +2372,23 @@ void calc_lookup_values_from_cond(THD *thd, COND *cond, TABLE_LIST *table,
       while ((item= li++))
       {
         if (item->type() == Item::FUNC_ITEM)
-          get_lookup_value(thd, (Item_func*)item, table, lookup_field_vals);
+        {
+          if (get_lookup_value(thd, (Item_func*)item, table, lookup_field_vals))
+            return 1;
+        }
         else
-          calc_lookup_values_from_cond(thd, item, table, lookup_field_vals);
+        {
+          if (calc_lookup_values_from_cond(thd, item, table, lookup_field_vals))
+            return 1;
         }
       }
-    return;
     }
-  else if (cond->type() == Item::FUNC_ITEM)
-    get_lookup_value(thd, (Item_func*) cond, table, lookup_field_vals);
-  return;
+    return 0;
+  }
+  else if (cond->type() == Item::FUNC_ITEM &&
+           get_lookup_value(thd, (Item_func*) cond, table, lookup_field_vals))
+    return 1;
+  return 0;
 }
 
 
@@ -2486,10 +2501,12 @@ static COND * make_cond_for_info_schema(COND *cond, TABLE_LIST *table)
   @param[in]      tables                I_S table
   @param[in, out] lookup_field_values   Struct which holds lookup values 
 
-  @return         void
+  @return
+    0             success
+    1             error, there can be no matching records for the condition
 */
 
-void get_lookup_field_values(THD *thd, COND *cond, TABLE_LIST *tables,
+bool get_lookup_field_values(THD *thd, COND *cond, TABLE_LIST *tables,
                              LOOKUP_FIELD_VALUES *lookup_field_values)
 {
   LEX *lex= thd->lex;
@@ -2503,7 +2520,7 @@ void get_lookup_field_values(THD *thd, COND *cond, TABLE_LIST *tables,
       lookup_field_values->db_value.length= strlen(wild);
       lookup_field_values->wild_db_value= 1;
     }
-    break;
+    return 0;
   case SQLCOM_SHOW_TABLES:
   case SQLCOM_SHOW_TABLE_STATUS:
   case SQLCOM_SHOW_TRIGGERS:
@@ -2516,14 +2533,13 @@ void get_lookup_field_values(THD *thd, COND *cond, TABLE_LIST *tables,
       lookup_field_values->table_value.length= strlen(wild);
       lookup_field_values->wild_table_value= 1;
     }
-    break;
+    return 0;
   default:
     /*
       The "default" is for queries over I_S.
       All previous cases handle SHOW commands.
     */
-    calc_lookup_values_from_cond(thd, cond, tables, lookup_field_values);
-    break;
+    return calc_lookup_values_from_cond(thd, cond, tables, lookup_field_values);
   }
 }
 
@@ -3113,7 +3129,11 @@ int get_all_tables(THD *thd, TABLE_LIST *tables, COND *cond)
   }
 
   schema_table_idx= get_schema_table_idx(schema_table);
-  get_lookup_field_values(thd, cond, tables, &lookup_field_vals);
+  if (get_lookup_field_values(thd, cond, tables, &lookup_field_vals))
+  {
+    error= 0;
+    goto err;
+  }
   DBUG_PRINT("INDEX VALUES",("db_name='%s', table_name='%s'",
                              lookup_field_vals.db_value.str,
                              lookup_field_vals.table_value.str));
@@ -3328,7 +3348,8 @@ int fill_schema_schemata(THD *thd, TABLE_LIST *tables, COND *cond)
 #endif
   DBUG_ENTER("fill_schema_shemata");
 
-  get_lookup_field_values(thd, cond, tables, &lookup_field_vals);
+  if (get_lookup_field_values(thd, cond, tables, &lookup_field_vals))
+    DBUG_RETURN(0);
   DBUG_PRINT("INDEX VALUES",("db_name='%s', table_name='%s'",
                              lookup_field_vals.db_value.str,
                              lookup_field_vals.table_value.str));