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

4 files changed, 37 insertions, 33 deletions

diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
index 9716f7c251c..d1146a99113 100644
--- a/sql/sql_acl.cc
+++ b/sql/sql_acl.cc
@@ -6057,9 +6057,12 @@ bool check_grant_column(THD *thd, GRANT_INFO *grant,
                                              table_name, TRUE) : NULL;
     grant->version= grant_version;		/* purecov: inspected */
   }
-  if (!(grant_table= grant->grant_table_user) &&
-      !(grant_table_role= grant->grant_table_role))
-    goto err;					/* purecov: deadcode */
+
+  grant_table= grant->grant_table_user;
+  grant_table_role= grant->grant_table_role;
+
+  if (!grant_table && !grant_table_role)
+    goto err;
 
   if (grant_table)
   {
@@ -6187,14 +6190,12 @@ bool check_grant_all_columns(THD *thd, ulong want_access_arg,
                              Field_iterator_table_ref *fields)
 {
   Security_context *sctx= thd->security_ctx;
-  ulong want_access= want_access_arg;
+  ulong UNINIT_VAR(want_access);
   const char *table_name= NULL;
-
   const char* db_name;
   GRANT_INFO *grant;
-  /* Initialized only to make gcc happy */
-  GRANT_TABLE *grant_table= NULL;
-  GRANT_TABLE *grant_table_role= NULL;
+  GRANT_TABLE *UNINIT_VAR(grant_table);
+  GRANT_TABLE *UNINIT_VAR(grant_table_role);
   /*
      Flag that gets set if privilege checking has to be performed on column
      level.
@@ -6238,16 +6239,14 @@ bool check_grant_all_columns(THD *thd, ulong want_access_arg,
 
     if (want_access)
     {
+      ulong have_access= 0;
       if (grant_table)
       {
         GRANT_COLUMN *grant_column=
           column_hash_search(grant_table, field_name,
                              (uint) strlen(field_name));
         if (grant_column)
-        {
-          using_column_privileges= TRUE;
-          want_access&= ~grant_column->rights;
-        }
+          have_access= grant_column->rights;
       }
       if (grant_table_role)
       {
@@ -6255,13 +6254,12 @@ bool check_grant_all_columns(THD *thd, ulong want_access_arg,
           column_hash_search(grant_table_role, field_name,
                              (uint) strlen(field_name));
         if (grant_column)
-        {
-          using_column_privileges= TRUE;
-          want_access&= ~grant_column->rights;
-        }
+          have_access|= grant_column->rights;
       }
 
-      if (!want_access)
+      if (have_access)
+        using_column_privileges= TRUE;
+      if (want_access & ~have_access)
         goto err;
     }
   }
@@ -6580,8 +6578,10 @@ ulong get_column_grant(THD *thd, GRANT_INFO *grant,
     grant->version= grant_version;              /* purecov: inspected */
   }
 
-  if (!(grant_table= grant->grant_table_user) &&
-      !(grant_table_role= grant->grant_table_role))
+  grant_table= grant->grant_table_user;
+  grant_table_role= grant->grant_table_role;
+
+  if (!grant_table && !grant_table_role)
     priv= grant->privilege;
   else
   {
diff --git a/sql/sql_db.cc b/sql/sql_db.cc
index 47c2e3bd406..7cc2caaa881 100644
--- a/sql/sql_db.cc
+++ b/sql/sql_db.cc
@@ -1470,18 +1470,17 @@ bool mysql_change_db(THD *thd, const LEX_STRING *new_db_name, bool force_switch)
   DBUG_PRINT("info",("Use database: %s", new_db_file_name.str));
 
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
-  db_access=
-    test_all_bits(sctx->master_access, DB_ACLS) ?
-    DB_ACLS :
-    acl_get(sctx->host,
-            sctx->ip,
-            sctx->priv_user,
-            new_db_file_name.str,
-            FALSE) | sctx->master_access;
-  if (sctx->priv_role[0])
+  if (test_all_bits(sctx->master_access, DB_ACLS))
+    db_access= DB_ACLS;
+  else
   {
-    /* include a possible currently set role for access */
-    db_access|= acl_get("", "", sctx->priv_role, new_db_file_name.str, FALSE);
+    db_access= acl_get(sctx->host, sctx->ip, sctx->priv_user,
+                        new_db_file_name.str, FALSE) | sctx->master_access;
+    if (sctx->priv_role[0])
+    {
+      /* include a possible currently set role for access */
+      db_access|= acl_get("", "", sctx->priv_role, new_db_file_name.str, FALSE);
+    }
   }
 
   if (!force_switch &&
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index 293081c21db..281ca26b64f 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -148,7 +148,7 @@ enum enum_sql_command {
   SQLCOM_SHOW_TRIGGERS,
 
   SQLCOM_LOAD,SQLCOM_SET_OPTION,SQLCOM_LOCK_TABLES,SQLCOM_UNLOCK_TABLES,
-  SQLCOM_GRANT, SQLCOM_GRANT_ROLE,
+  SQLCOM_GRANT,
   SQLCOM_CHANGE_DB, SQLCOM_CREATE_DB, SQLCOM_DROP_DB, SQLCOM_ALTER_DB,
   SQLCOM_REPAIR, SQLCOM_REPLACE, SQLCOM_REPLACE_SELECT,
   SQLCOM_CREATE_FUNCTION, SQLCOM_DROP_FUNCTION,
@@ -169,7 +169,6 @@ enum enum_sql_command {
   SQLCOM_SHOW_WARNS, SQLCOM_EMPTY_QUERY, SQLCOM_SHOW_ERRORS,
   SQLCOM_SHOW_STORAGE_ENGINES, SQLCOM_SHOW_PRIVILEGES,
   SQLCOM_HELP, SQLCOM_CREATE_USER, SQLCOM_DROP_USER, SQLCOM_RENAME_USER,
-  SQLCOM_CREATE_ROLE, SQLCOM_DROP_ROLE, SQLCOM_REVOKE_ROLE,
   SQLCOM_REVOKE_ALL, SQLCOM_CHECKSUM,
   SQLCOM_CREATE_PROCEDURE, SQLCOM_CREATE_SPFUNCTION, SQLCOM_CALL,
   SQLCOM_DROP_PROCEDURE, SQLCOM_ALTER_PROCEDURE,SQLCOM_ALTER_FUNCTION,
@@ -197,6 +196,7 @@ enum enum_sql_command {
   SQLCOM_SHOW_USER_STATS, SQLCOM_SHOW_TABLE_STATS, SQLCOM_SHOW_INDEX_STATS,
   SQLCOM_SHOW_CLIENT_STATS,
   SQLCOM_SHOW_EXPLAIN, SQLCOM_SHUTDOWN,
+  SQLCOM_CREATE_ROLE, SQLCOM_DROP_ROLE, SQLCOM_GRANT_ROLE, SQLCOM_REVOKE_ROLE,
 
   /*
     When a command is added here, be sure it's also added in mysqld.cc
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;