Fixes for mysql-test failures

mysql-test/r/acl_roles_show_grants.result:
  one can do SHOW GRANTS for himself
mysql-test/t/acl_roles_set_role-table-column-priv.test:
  correct error message
mysql-test/t/acl_roles_show_grants.test:
  one can SHOW GRANTS for himself
sql/sql_acl.cc:
  bugfixing:
  * don't assign with && - it can shortcut and the second assignment won't be executed
  * correct the test in check_grant_all_columns() - want_access should not be modified
  *
sql/sql_cmd.h.OTHER:
  add new commands at the end
sql/sql_db.cc:
  don't call acl_get() if all privileges are already satisfied
  (crashes when run with --skip-grants, because acl data stuctures aren't initialized)
sql/sql_parse.cc:
  * test for current_user in get_current_user()
  * map explicitly specified user@host to current_user

1 files changed, 6 insertions, 1 deletions

diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 9d17d9c3e31..997ba7f97ea 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -4001,6 +4001,11 @@ end_with_restore_list:
     LEX_USER *grant_user= lex->grant_user;
     if (!grant_user)
       goto error;
+
+    if (grant_user->user.str &&
+        !strcmp(thd->security_ctx->priv_user, grant_user->user.str))
+      grant_user= &current_user;
+
     if (grant_user == &current_user ||
         grant_user == &current_role ||
         grant_user == &current_user_and_current_role ||
@@ -7752,7 +7757,7 @@ LEX_USER *create_definer(THD *thd, LEX_STRING *user_name, LEX_STRING *host_name)
 
 LEX_USER *get_current_user(THD *thd, LEX_USER *user)
 {
-  if (!user->user.str)  // current_user
+  if (user == &current_user)  // current_user
     return create_default_definer(thd);
 
   return user;