Fix broken build for gcc 7 in MySQL 5.6

Tor Didriksen · Tor Didriksen · commit 65353097d25e · 2018-01-30T10:47:06.000+01:00
Even with -DMYSQL_MAINTAINER_MODE=0 the build is broken with gcc 7

sql/sql_acl.cc:2732:23: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   DBUG_ASSERT(host != '\0');

Fix: compare with 0 rather than '\0'
diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
@@ -1,4 +1,4 @@
-/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -2729,7 +2729,7 @@ bool change_password(THD *thd, const char *host, const char *user,
   }
   mysql_mutex_assert_owner(&acl_cache->lock);
   table->use_all_columns();
-  DBUG_ASSERT(host != '\0');
+  DBUG_ASSERT(host != 0);
   table->field[MYSQL_USER_FIELD_HOST]->store(host, strlen(host),
                                              system_charset_info);
   table->field[MYSQL_USER_FIELD_USER]->store(user, strlen(user),
@@ -3166,7 +3166,7 @@ update_user_table(THD *thd, TABLE *table,
   if (!is_user_table_positioned)
   {
     table->use_all_columns();
-    DBUG_ASSERT(host != '\0');
+    DBUG_ASSERT(host != 0);
     table->field[MYSQL_USER_FIELD_HOST]->store(host, (uint) strlen(host),
 					       system_charset_info);
     table->field[MYSQL_USER_FIELD_USER]->store(user, (uint) strlen(user),
@@ -3302,7 +3302,7 @@ static int replace_user_table(THD *thd, TABLE *table, LEX_USER *combo,
     goto end;
 
   table->use_all_columns();
-  DBUG_ASSERT(combo->host.str != '\0');
+  DBUG_ASSERT(combo->host.str != 0);
   table->field[MYSQL_USER_FIELD_HOST]->store(combo->host.str,combo->host.length,
                                              system_charset_info);
   table->field[MYSQL_USER_FIELD_USER]->store(combo->user.str,combo->user.length,
@@ -3393,7 +3393,7 @@ static int replace_user_table(THD *thd, TABLE *table, LEX_USER *combo,
 
     old_row_exists = 0;
     restore_record(table,s->default_values);
-    DBUG_ASSERT(combo->host.str != '\0');
+    DBUG_ASSERT(combo->host.str != 0);
     table->field[MYSQL_USER_FIELD_HOST]->store(combo->host.str,combo->host.length,
                                                system_charset_info);
     table->field[MYSQL_USER_FIELD_USER]->store(combo->user.str,combo->user.length,
