Fixes bug when we run bcmp() on row when the storage engine hasn't filled in all fields in the row.

This was triggered by innodb.innodb_multi_update, where we had a static length row without nulls and xtradb didn't fill in the delete-marker byte


include/my_bitmap.h:
  Added prototype for bitmap_union_is_set_all()
mysys/my_bitmap.c:
  Added function to check if union of two bit maps covers all bits.
sql/mysql_priv.h:
  Updated protype for compare_record()
sql/sql_insert.cc:
  Send to compare_record() flag if all fields are used.
sql/sql_select.cc:
  Set share->null_bytes_for_compare.
sql/sql_update.cc:
  In compare_record() don't use the fast cmp_record() (which is basically memcmp) if we don't know that all fields exists.
  Don't compare the null_bytes if there is no data there.
sql/table.cc:
  Store in share->null_bytes_for_compare the number of bytes that has null or bit fields (but not delete marker)
  Store in can_cmp_whole_record if we can use memcmp() (assuming all rows are read) to compare rows in compare_record()
sql/table.h:
  Added two elements in table->share to speed up checking how updated rows can be compared.

1 files changed, 2 insertions, 0 deletions

diff --git a/include/my_bitmap.h b/include/my_bitmap.h
index 78642df3362..2c50ca3ec75 100644
--- a/include/my_bitmap.h
+++ b/include/my_bitmap.h
@@ -53,6 +53,8 @@ extern my_bool bitmap_is_overlapping(const MY_BITMAP *map1,
 extern my_bool bitmap_test_and_set(MY_BITMAP *map, uint bitmap_bit);
 extern my_bool bitmap_test_and_clear(MY_BITMAP *map, uint bitmap_bit);
 extern my_bool bitmap_fast_test_and_set(MY_BITMAP *map, uint bitmap_bit);
+extern my_bool bitmap_union_is_set_all(const MY_BITMAP *map1,
+                                       const MY_BITMAP *map2);
 extern uint bitmap_set_next(MY_BITMAP *map);
 extern uint bitmap_get_first(const MY_BITMAP *map);
 extern uint bitmap_get_first_set(const MY_BITMAP *map);