MDEV-27304 SHOW ... result columns are right-aligned

--version=value was setting sys_var::CONFIG (meaning, the value
came from the config file), but the filename was left as NULL.

mysql-test/suite/sys_vars/r/version.result

@@ -2,3 +2,19 @@ SELECT @@version;
 @@version
 my_favorite_version
 1
+select * from information_schema.system_variables where variable_name='version';
+VARIABLE_NAME	VERSION
+SESSION_VALUE	NULL
+GLOBAL_VALUE	my_favorite_version
+GLOBAL_VALUE_ORIGIN	COMMAND-LINE
+DEFAULT_VALUE	NULL
+VARIABLE_SCOPE	GLOBAL
+VARIABLE_TYPE	VARCHAR
+VARIABLE_COMMENT	Server version number. It may also include a suffix with configuration or build information. -debug indicates debugging support was enabled on the server, and -log indicates at least one of the binary log, general log or slow query log are enabled, for example 10.1.1-MariaDB-mariadb1precise-log.
+NUMERIC_MIN_VALUE	NULL
+NUMERIC_MAX_VALUE	NULL
+NUMERIC_BLOCK_SIZE	NULL
+ENUM_VALUE_LIST	NULL
+READ_ONLY	YES
+COMMAND_LINE_ARGUMENT	NULL
+GLOBAL_VALUE_PATH	NULL

mysql-test/suite/sys_vars/t/version.test

@@ -4,3 +4,4 @@ perl;
         grep /my_favorite_version/, `$ENV{MYSQL} -e status`;
   print "$cnt\n";
 EOF
+query_vertical select * from information_schema.system_variables where variable_name='version';

sql/mysqld.cc

@@ -7967,7 +7967,8 @@ mysqld_get_one_option(const struct my_option *opt, const char *argument,
     if (argument)
     {
       strmake(server_version, argument, sizeof(server_version) - 1);
-      set_sys_var_value_origin(&server_version_ptr, sys_var::CONFIG);
+      set_sys_var_value_origin(&server_version_ptr,
+                *filename ? sys_var::CONFIG : sys_var::COMMAND_LINE, filename);
       using_custom_server_version= true;
     }
 #ifndef EMBEDDED_LIBRARY

sql/set_var.cc

@@ -1278,7 +1278,8 @@ int fill_sysvars(THD *thd, TABLE_LIST *tables, COND *cond)
   and update it directly.
 */
 
-void set_sys_var_value_origin(void *ptr, enum sys_var::where here)
+void set_sys_var_value_origin(void *ptr, enum sys_var::where here,
+                              const char *filename)
 {
   bool found __attribute__((unused))= false;
   DBUG_ASSERT(!mysqld_server_started); // only to be used during startup
@@ -1289,6 +1290,7 @@ void set_sys_var_value_origin(void *ptr, enum sys_var::where here)
     if (var->option.value == ptr)
     {
       found= true;
+      var->origin_filename= filename;
       var->value_origin= here;
       /* don't break early, search for all matches */
     }

sql/set_var.h

@@ -450,7 +450,8 @@ int sql_set_variables(THD *thd, List<set_var_base> *var_list, bool free);
     }                                                   \
   } while(0)
 
-void set_sys_var_value_origin(void *ptr, enum sys_var::where here);
+void set_sys_var_value_origin(void *ptr, enum sys_var::where here,
+                              const char *filename= NULL);
 
 enum sys_var::where get_sys_var_value_origin(void *ptr);
 inline bool IS_SYSVAR_AUTOSIZE(void *ptr)

storage/perfschema/unittest/pfs_server_stubs.cc

@@ -51,7 +51,7 @@ void sql_print_warning(const char *format, ...)
 }
 
 class sys_var { public: enum where { AUTO }; };
-void set_sys_var_value_origin(void *ptr, enum sys_var::where here)
+void set_sys_var_value_origin(void *, enum sys_var::where, const char *)
 {
 }