comments: Add a checksum to the name of comment pages, to avoid merge conflicts when...

diff --git a/IkiWiki/Plugin/comments.pm b/IkiWiki/Plugin/comments.pm
index 517e16f9ff8afd0ca3de21df8ace8558a03173bb..6340fc2cb466bd925208d8bf21462ff5f12b4466 100644 (file)
--- a/IkiWiki/Plugin/comments.pm
+++ b/IkiWiki/Plugin/comments.pm
@@ -377,8 +377,6 @@ sub editcomment ($$) {
        IkiWiki::check_canedit($page, $cgi, $session);
        $postcomment=0;
 
-       my $location=unique_comment_location($page, $config{srcdir});
-
        my $content = "[[!comment format=$type\n";
 
        # FIXME: handling of double quotes probably wrong?
@@ -410,8 +408,11 @@ sub editcomment ($$) {
        my $subject = $form->field('subject');
        if (defined $subject && length $subject) {
                $subject =~ s/"/"/g;
-               $content .= " subject=\"$subject\"\n";
        }
+       else {
+               $subject = "comment ".(num_comments($page, $config{srcdir}) + 1);
+       }
+       $content .= " subject=\"$subject\"\n";
 
        $content .= " date=\"" . decode_utf8(strftime('%Y-%m-%dT%H:%M:%SZ', gmtime)) . "\"\n";
 
@@ -421,6 +422,8 @@ sub editcomment ($$) {
        $editcontent =~ s/"/\\"/g;
        $content .= " content=\"\"\"\n$editcontent\n\"\"\"]]\n";
 
+       my $location=unique_comment_location($page, $content, $config{srcdir});
+
        # This is essentially a simplified version of editpage:
        # - the user does not control the page that's created, only the parent
        # - it's always a create operation, never an edit
@@ -458,7 +461,7 @@ sub editcomment ($$) {
 
                if (! $ok) {
                        my $penddir=$config{wikistatedir}."/comments_pending";
-                       $location=unique_comment_location($page, $penddir);
+                       $location=unique_comment_location($page, $content, $penddir);
                        writefile("$location._comment", $penddir, $content);
                        IkiWiki::printheader($session);
                        print IkiWiki::misctemplate(gettext(gettext("comment stored for moderation")),
@@ -554,7 +557,7 @@ sub commentmoderation ($$) {
                                if ($action eq 'Accept') {
                                        my $content=eval { readfile($file) };
                                        next if $@; # file vanished since form was displayed
-                                       my $dest=unique_comment_location($page, $config{srcdir})."._comment";
+                                       my $dest=unique_comment_location($page, $content, $config{srcdir})."._comment";
                                        writefile($dest, $config{srcdir}, $content);
                                        if ($config{rcs} and $config{comments_commit}) {
                                                IkiWiki::rcs_add($dest);
@@ -813,15 +816,28 @@ sub pagetemplate (@) {
        }
 }
 
-sub unique_comment_location ($) {
+sub num_comments ($$) {
        my $page=shift;
        my $dir=shift;
 
+       my @comments=glob("$dir/$page/$config{comments_pagename}*._comment");
+       return @comments;
+}
+
+sub unique_comment_location ($$$) {
+       my $page=shift;
+
+       eval q{use Digest::MD5 'md5_hex'};
+       error($@) if $@;
+       my $content_md5=md5_hex(shift);
+
+       my $dir=shift;
+
        my $location;
-       my $i = 0;
+       my $i = num_comments($page, $dir);
        do {
                $i++;
-               $location = "$page/$config{comments_pagename}$i";
+               $location = "$page/$config{comments_pagename}${i}_${content_md5}";
        } while (-e "$dir/$location._comment");
 
        return $location;

diff --git a/debian/changelog b/debian/changelog
index ee6f9adfb019cb3e736f10dda624769f0c5b5fa3..984351415b1293610db48ee5dfa94e2d2eb97f8d 100644 (file)
--- a/debian/changelog
+++ b/debian/changelog
@@ -8,6 +8,9 @@ ikiwiki (3.20091219) UNRELEASED; urgency=low
     can be generated at any time using ikiwiki --dumpsetup so I do
     not see a reason to ship it. Closes: #562183
   * Use env hack in python scripts.
+  * comments: Add a checksum to the name of comment pages, to
+    avoid merge conflicts when comments are posted to two branches of a
+    site.
 
  -- Joey Hess <joeyh@debian.org>  Fri, 25 Dec 2009 14:31:22 -0500
 

diff --git a/doc/todo/conflict_free_comment_merges.mdwn b/doc/todo/conflict_free_comment_merges.mdwn
index e0e8acb34c89ee8530ea6671961c0d0f960ba8a2..2cef0ee8cd3285f687c52f46b615d3e5aa07157b 100644 (file)
--- a/doc/todo/conflict_free_comment_merges.mdwn
+++ b/doc/todo/conflict_free_comment_merges.mdwn
@@ -12,3 +12,12 @@ title is specified, to retain the current behavior of the default title
 being "comment N".
 
 What do you think [[smcv]]? --[[Joey]] 
+
+> I had to use md5sums, as sha1sum perl module may not be available and I
+> didn't want to drag it in. But I think that's ok; this doesn't need to be
+> cryptographically secure and even the chances of being able to
+> purposefully cause a md5 collision and thus an undesired merge conflict
+> are quite low since it modifies the input text and adds a date stamp to
+> it.
+>
+> Anyway, I think it's good, [[[done]] --[[Joey]]