implement basic subject_tag manipuration

1 files changed, 13 insertions, 3 deletions

diff --git a/fml/lib/FML/Header/Subject.pm b/fml/lib/FML/Header/Subject.pm
index 27154f92..ed104e2c 100644
--- a/fml/lib/FML/Header/Subject.pm
+++ b/fml/lib/FML/Header/Subject.pm
@@ -36,9 +36,7 @@ sub rewrite_subject_tag
     my $subject = $header->get('subject');
 
     # de-tag
-    my $retag   = _regexp_compile($tag);
-    $subject  =~ s/$retag//g;
-    $subject  =~ s/^\s*//;
+    $subject = _delete_subject_tag( $subject, $tag );
 
     # add the updated tag
     $tag = sprintf($tag, $ml_name, $args->{ id });
@@ -47,6 +45,18 @@ sub rewrite_subject_tag
 }
 
 
+sub _delete_subject_tag
+{
+    my ($subject, $tag) = @_;
+    my $retag = _regexp_compile($tag);
+
+    $subject  =~ s/$retag//g;
+    $subject  =~ s/^\s*//;
+
+    return $subject;
+}
+
+
 # Descriptions: create regexp for a subject tag, for example
 #               "[%s %05d]" => "\[\S+ \d+\]"
 #    Arguments: a subject tag string