Bug#14025221 FOREIGN KEY REFERENCES FREED MEMORY AFTER DROP INDEX

dict_table_replace_index_in_foreign_list(): Replace the dropped index
also in the foreign key constraints of child tables that are
referencing this table.

row_ins_check_foreign_constraint(): If the underlying index is
missing, refuse the operation.

rb:1051 approved by Jimmy Yang

storage/innodb_plugin/dict/dict0dict.c

@@ -4872,6 +4872,28 @@ dict_table_replace_index_in_foreign_list(
 			foreign->foreign_index = new_index;
 		}
 	}
+
+
+	for (foreign = UT_LIST_GET_FIRST(table->referenced_list);
+	     foreign;
+	     foreign = UT_LIST_GET_NEXT(referenced_list, foreign)) {
+
+		dict_index_t*	new_index;
+
+		if (foreign->referenced_index == index) {
+			ut_ad(foreign->referenced_table == index->table);
+
+			new_index = dict_foreign_find_index(
+				foreign->referenced_table,
+				foreign->referenced_col_names,
+				foreign->n_fields, index,
+				/*check_charsets=*/TRUE, /*check_null=*/FALSE);
+			ut_ad(new_index || !trx->check_foreigns);
+			ut_ad(!new_index || new_index->table == index->table);
+
+			foreign->referenced_index = new_index;
+		}
+	}
 }
 
 /**********************************************************************//**

storage/innodb_plugin/row/row0ins.c

@@ -1296,7 +1296,8 @@ row_ins_check_foreign_constraint(
 		check_index = foreign->foreign_index;
 	}
 
-	if (check_table == NULL || check_table->ibd_file_missing) {
+	if (check_table == NULL || check_table->ibd_file_missing
+	    || check_index == NULL) {
 		if (check_ref) {
 			FILE*	ef = dict_foreign_err_file;
 
@@ -1331,9 +1332,6 @@ row_ins_check_foreign_constraint(
 		goto exit_func;
 	}
 
-	ut_a(check_table);
-	ut_a(check_index);
-
 	if (check_table != table) {
 		/* We already have a LOCK_IX on table, but not necessarily
 		on check_table */