MDEV-4570 [PATCH] Sys_query_cache_limit initialization depends on...

MDEV-4570 [PATCH] Sys_query_cache_limit initialization depends on initialization in other source files

sql/mysqld.cc

@@ -488,6 +488,7 @@ ulong slave_max_allowed_packet= 0;
 ulonglong binlog_stmt_cache_size=0;
 ulonglong  max_binlog_stmt_cache_size=0;
 ulonglong query_cache_size=0;
+ulong query_cache_limit=0;
 ulong refresh_version;  /* Increments on each reload */
 ulong executed_events=0;
 query_id_t global_query_id;
@@ -4466,6 +4467,7 @@ static int init_server_components()
   query_cache_set_min_res_unit(query_cache_min_res_unit);
   query_cache_init();
   query_cache_resize(query_cache_size);
+  query_cache_result_size_limit(query_cache_limit);
   my_rnd_init(&sql_rand,(ulong) server_start_time,(ulong) server_start_time/2);
   setup_fpu();
   init_thr_lock();

sql/mysqld.h

@@ -156,6 +156,7 @@ extern ulong delayed_insert_threads, delayed_insert_writes;
 extern ulong delayed_rows_in_use,delayed_insert_errors;
 extern ulong slave_open_temp_tables;
 extern ulonglong query_cache_size;
+extern ulong query_cache_limit;
 extern ulong query_cache_min_res_unit;
 extern ulong slow_launch_threads, slow_launch_time;
 extern ulong table_cache_size, table_def_size;

sql/sys_vars.cc

@@ -2245,6 +2245,11 @@ static bool fix_query_cache_size(sys_var *self, THD *thd, enum_var_type type)
   query_cache_size= new_cache_size;
   return false;
 }
+static bool fix_query_cache_limit(sys_var *self, THD *thd, enum_var_type type)
+{
+  query_cache.result_size_limit(query_cache_limit);
+  return false;
+}
 static Sys_var_ulonglong Sys_query_cache_size(
        "query_cache_size",
        "The memory allocated to store results from old queries",
@@ -2256,8 +2261,10 @@ static Sys_var_ulonglong Sys_query_cache_size(
 static Sys_var_ulong Sys_query_cache_limit(
        "query_cache_limit",
        "Don't cache results that are bigger than this",
-       GLOBAL_VAR(query_cache.query_cache_limit), CMD_LINE(REQUIRED_ARG),
-       VALID_RANGE(0, UINT_MAX), DEFAULT(1024*1024), BLOCK_SIZE(1));
+       GLOBAL_VAR(query_cache_limit), CMD_LINE(REQUIRED_ARG),
+       VALID_RANGE(0, UINT_MAX), DEFAULT(1024*1024), BLOCK_SIZE(1),
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(NULL),
+       ON_UPDATE(fix_query_cache_limit));
 
 static bool fix_qcache_min_res_unit(sys_var *self, THD *thd, enum_var_type type)
 {