MDEV-21374: When "--help --verbose" prints out configuration file paths, the...

MDEV-21374: When "--help --verbose" prints out configuration file paths, the --defaults-file option is not considered

* `--defaults-file` option is showed only in `--help --verbose` if
applied
* `--default-extra-file` is showing correctly now in `--help --verbose`,
previously it was treated as a directory with appended `my.cnf`

mysql-test/r/mysqld--defaults-file.result

@@ -10,3 +10,15 @@ Could not open required defaults file: MYSQL_TEST_DIR/with.ext
 Fatal error in defaults handling. Program aborted
 Could not open required defaults file: MYSQL_TEST_DIR/no_extension
 Fatal error in defaults handling. Program aborted
+#
+# MDEV-21374: When "--help --verbose" prints out configuration file paths,
+# the --defaults-file option is not considered
+#
+# Test on `defaults-file`
+Default options are read from the following files in the given order:
+MYSQLTEST_VARDIR/my.cnf
+The following groups are read: mysqld server mysqld-10.1 mariadb mariadb-10.1 client-server galera
+# Test on `defaults-extra-file`
+Default options are read from the following files in the given order:
+<first-defaults> MYSQLTEST_VARDIR/my_test.cnf ~/.my.cnf 
+The following groups are read: mysqld server mysqld-10.1 mariadb mariadb-10.1 client-server galera

mysql-test/t/mysqld--defaults-file.test

@@ -29,3 +29,19 @@ exec $MYSQLD --defaults-file=with.ext --print-defaults 2>&1;
 --error 1
 exec $MYSQLD --defaults-file=no_extension --print-defaults 2>&1;
 
+--echo #
+--echo # MDEV-21374: When "--help --verbose" prints out configuration file paths,
+--echo # the --defaults-file option is not considered
+--echo #
+
+--echo # Test on `defaults-file`
+--replace_result $MYSQLTEST_VARDIR MYSQLTEST_VARDIR
+exec $MYSQLD --defaults-file=$MYSQLTEST_VARDIR/my.cnf --help --verbose | grep -A 2 'Default options are read';
+
+--echo # Test on `defaults-extra-file`
+# <first-defaults> = `/etc/my.cnf /etc/mysql/my.cnf`
+# Using sysconfdir configuration, we don't always have `/etc/mysql/my.cnf`, so replace them with a regex as well.
+copy_file $MYSQLTEST_VARDIR/my.cnf $MYSQLTEST_VARDIR/my_test.cnf;
+--replace_regex /.*my_test.cnf/<first-defaults> MYSQLTEST_VARDIR\/my_test.cnf/
+exec $MYSQLD --defaults-extra-file=$MYSQLTEST_VARDIR/my_test.cnf --help --verbose | grep -A 2 'Default options are read';
+remove_file $MYSQLTEST_VARDIR/my_test.cnf;

mysys/my_default.c

@@ -1035,6 +1035,11 @@ void my_print_default_files(const char *conf_file)
   char name[FN_REFLEN], **ext;
 
   puts("\nDefault options are read from the following files in the given order:");
+  if (my_defaults_file)
+  {
+    puts(my_defaults_file);
+    return;
+  }
 
   if (dirname_length(conf_file))
     fputs(conf_file,stdout);
@@ -1059,7 +1064,12 @@ void my_print_default_files(const char *conf_file)
           if (**dirs)
             pos= *dirs;
           else if (my_defaults_extra_file)
+          {
             pos= my_defaults_extra_file;
+            fputs(pos, stdout);
+            fputs(" ", stdout);
+            continue;
+          }
           else
             continue;
           end= convert_dirname(name, pos, NullS);