Automerge.

mysql-test/r/innodb_mysql.result

@@ -2408,4 +2408,13 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	const	PRIMARY	NULL	NULL	NULL	1	Impossible ON condition
 1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	3	Using where
 DROP TABLE t1,t2;
+#
+# Bug #53830: !table || (!table->read_set || bitmap_is_set(table->read_set, field_index))
+#
+CREATE TABLE t1 (a INT, b INT, c INT, d INT,
+PRIMARY KEY(a,b,c), KEY(b,d))
+ENGINE=InnoDB;
+INSERT INTO t1 VALUES (0, 77, 1, 3);
+UPDATE t1 SET d = 0 WHERE b = 77 AND c = 25;
+DROP TABLE t1;
 End of 5.1 tests

mysql-test/t/innodb_mysql.test

@@ -649,4 +649,18 @@ EXPLAIN SELECT t1.id,t2.id FROM t2 LEFT JOIN t1 ON t1.id>=74 AND t1.id<=0
 
 DROP TABLE t1,t2;
 
+
+--echo #
+--echo # Bug #53830: !table || (!table->read_set || bitmap_is_set(table->read_set, field_index))
+--echo #
+
+CREATE TABLE t1 (a INT, b INT, c INT, d INT,
+                 PRIMARY KEY(a,b,c), KEY(b,d))
+                 ENGINE=InnoDB;
+INSERT INTO t1 VALUES (0, 77, 1, 3);
+
+UPDATE t1 SET d = 0 WHERE b = 77 AND c = 25;
+
+DROP TABLE t1;
+
 --echo End of 5.1 tests

sql/sql_update.cc

@@ -397,7 +397,7 @@ int mysql_update(THD *thd,
       matching rows before updating the table!
     */
     if (used_index < MAX_KEY && old_covering_keys.is_set(used_index))
-      table->mark_columns_used_by_index(used_index);
+      table->add_read_columns_used_by_index(used_index);
     else
     {
       table->use_all_columns();

sql/table.cc

@@ -4377,6 +4377,27 @@ void st_table::mark_columns_used_by_index(uint index)
 }
 
 
+/*
+  Add fields used by a specified index to the table's read_set.
+
+  NOTE:
+    The original state can be restored with
+    restore_column_maps_after_mark_index().
+*/
+
+void st_table::add_read_columns_used_by_index(uint index)
+{
+  MY_BITMAP *bitmap= &tmp_set;
+  DBUG_ENTER("st_table::add_read_columns_used_by_index");
+
+  set_keyread(TRUE);
+  bitmap_copy(bitmap, read_set);
+  mark_columns_used_by_index_no_reset(index, bitmap);
+  column_bitmaps_set(bitmap, write_set);
+  DBUG_VOID_RETURN;
+}
+
+
 /*
   Restore to use normal column maps after key read
 

sql/table.h

@@ -865,6 +865,7 @@ struct st_table {
   void prepare_for_position(void);
   void mark_columns_used_by_index_no_reset(uint index, MY_BITMAP *map);
   void mark_columns_used_by_index(uint index);
+  void add_read_columns_used_by_index(uint index);
   void restore_column_maps_after_mark_index();
   void mark_auto_increment_column(void);
   void mark_columns_needed_for_update(void);