From ffc33cffe3e06956537b03b688543caa367eba5b Mon Sep 17 00:00:00 2001 From: Annamalai Gurusami Date: Wed, 29 Oct 2014 16:53:53 +0530 Subject: [PATCH] Bug #19908343 SERVER CRASHES WHEN EXECUTING ALTER TABLE Problem: In the function dict_foreign_remove_from_cache(), the rb tree was updated without actually verifying whether the given foreign key object is there in the rb tree or not. There can be an existing foreign key object with the same id in the rb tree, which must not be removed. Such a scenario comes when an attempt is made to add a foreign key object with a duplicate identifier. Solution: When the foreign key object is removed from the dictionary cache, ensure that the foreign key object removed from the rbt is the correct one. rb#7168 approved by Jimmy and Marko. --- storage/innobase/dict/dict0dict.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/storage/innobase/dict/dict0dict.c b/storage/innobase/dict/dict0dict.c index 63571bb26c8..c298f867ae3 100644 --- a/storage/innobase/dict/dict0dict.c +++ b/storage/innobase/dict/dict0dict.c @@ -2529,8 +2529,15 @@ dict_foreign_remove_from_cache( foreign); rbt = foreign->referenced_table->referenced_rbt; + if (rbt != NULL) { - rbt_delete(rbt, foreign->id); + const ib_rbt_node_t* node + = rbt_lookup(rbt, foreign->id); + dict_foreign_t* val = *(dict_foreign_t**) node->value; + + if (val == foreign) { + rbt_delete(rbt, foreign->id); + } } } @@ -2543,7 +2550,13 @@ dict_foreign_remove_from_cache( rbt = foreign->foreign_table->foreign_rbt; if (rbt != NULL) { - rbt_delete(rbt, foreign->id); + const ib_rbt_node_t* node + = rbt_lookup(rbt, foreign->id); + dict_foreign_t* val = *(dict_foreign_t**) node->value; + + if (val == foreign) { + rbt_delete(rbt, foreign->id); + } } }