SID-00025: CommentPlugin loses data

Status:	Answered	TWiki version:	4.2.3	Perl version:	5.8.8
Category:	CategoryPlugins	Server OS:	Fedora core 6	Last update:	17 years ago

The CommentPlugin loses data if it's targeted before/after a missing anchor.

Consider this case:

%COMMENT{type="above" cols="100" target="%INCLUDINGTOPIC%#LatestComment"}%

Try adding a comment here:

The specified anchor does not exist - in this case, it was corrupted by the WYSIWYG plugin. Comment.pm tries a s//, but doesn't notice that it fails.

In any case, an error setting up the page should not cause user data to be lost. I marked this report Urgent because it results in user data loss.

Here's a (somewhat ugly) patch:

--- lib/TWiki/Plugins/CommentPlugin/Comment.pm~ 2008-09-11 23:41:58.000000000 -0400
+++ lib/TWiki/Plugins/CommentPlugin/Comment.pm  2009-01-10 13:45:46.000000000 -0500
@@ -309,32 +309,35 @@
             $text .= "\n" unless $output =~ m/^\n/s;
             $text .= $output;
             $text .= "\n" unless $text =~ m/\n$/s;
         } else {
             if ( $location ) {
                 if ( $position eq 'BEFORE' ) {
-                    $text =~ s/(?<!location\=\")($location)/$output$1/m;
+                    $text .= $output unless( $text =~ s/(?<!location\=\")($location)/$output$1/m );
                 } else { # AFTER
-                    $text =~ s/(?<!location\=\")($location)/$1$output/m;
+                    $text .= $output unless( $text =~ s/(?<!location\=\")($location)/$1$output/m );
                 }
+               $text .= "\n" unless $text =~ m/\n$/s;
             } elsif ( $anchor ) {
                 # position relative to anchor
                 if ( $position eq 'BEFORE' ) {
-                    $text =~ s/^($anchor\s)/$output$1/m;
+                    $text .= $output unless( $text =~ s/^($anchor\s)/$output$1/m );
                 } else { # AFTER
-                    $text =~ s/^($anchor\s)/$1$output/m;
+                    $text .= $output unless( $text =~ s/^($anchor\s)/$1$output/m );
                 }
+               $text .= "\n" unless $text =~ m/\n$/s;
             } else {
                 # Position relative to index'th comment
                 my $idx = 0;
                 unless( $text =~ s((%COMMENT({.*?})?%.*\n))
                           (&_nth($1,\$idx,$position,$index,$output))eg ) {
                     # If there was a problem adding relative to the comment,
                     # add to the end of the topic
                     $text .= $output;
                 };
+               $text .= "\n" unless $text =~ m/\n$/s;
             }
         }
     }

     if (defined $remove) {
         # remove the index'th comment box

Discussion and Answer

Thanks Timothe. Please file a bug report at TWikibug:CommentPlugin to track this.

-- PeterThoeny - 10 Jan 2009

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