second try at merging and conflicts support

diff --git a/ikiwiki b/ikiwiki
index 70ede428852d2048609dfafd38c5a75b9270bf6f..78c706c31bea31afabd8479039d76122b0beeead 100755 (executable)
--- a/ikiwiki
+++ b/ikiwiki
@@ -461,18 +461,43 @@ sub rcs_update () { #{{{
        }
 } #}}}
 
-sub rcs_commit ($$) { #{{{
+sub rcs_prepedit ($) { #{{{
+       # Prepares to edit a file under revision control. Returns a token
+       # that must be passed into rcs_commit when the file is ready
+       # for committing.
+       # The file is relative to the srcdir.
+       my $file=shift;
+       
+       if (-d "$config{srcdir}/.svn") {
+               # For subversion, return the revision of the file when
+               # editing begins.
+               my $rev=svn_info("Revision", "$config{srcdir}/$file");
+               return defined $rev ? $rev : "";
+       }
+} #}}}
+
+sub rcs_commit ($$$) { #{{{
        # Tries to commit the page; returns undef on _success_ and
        # a version of the page with the rcs's conflict markers on failure.
        # The file is relative to the srcdir.
        my $file=shift;
        my $message=shift;
+       my $rcstoken=shift;
 
        if (-d "$config{srcdir}/.svn") {
-               # svn up to let svn merge in other changes
-               if (system("svn", "update", "-quiet", "$config{srcdir}/$file") != 0) {
-                       warn("svn update failed\n");
+               # Check to see if the page has been changed by someone
+               # else since rcs_prepedit was called.
+               my $oldrev=int($rcstoken);
+               my $rev=svn_info("Revision", "$config{srcdir}/$file");
+               if ($rev != $oldrev) {
+                       # Merge their changes into the file that we've
+                       # changed.
+                       if (system("svn", "merge", "--quiet", "-r$oldrev:$rev",
+                                  "$config{srcdir}/$file") != 0) {
+                               warn("svn merge -r$oldrev:$rev failed\n");
+                       }
                }
+
                if (system("svn", "commit", "--quiet", "-m",
                           possibly_foolish_untaint($message),
                           "$config{srcdir}/$file") != 0) {
@@ -504,6 +529,15 @@ sub rcs_add ($) { #{{{
        }
 } #}}}
 
+sub svn_info ($$) { #{{{
+       my $file=shift;
+       my $field=shift;
+
+       my $info=`LANG=C svn info $file`;
+       my ($ret)=$info=~/^$field: (.*)$/m;
+       return $ret;
+} #}}}
+
 sub rcs_recentchanges ($) { #{{{
        my $num=shift;
        my @ret;
@@ -513,8 +547,7 @@ sub rcs_recentchanges ($) { #{{{
        eval q{use Time::Duration};
        
        if (-d "$config{srcdir}/.svn") {
-               my $info=`LANG=C svn info $config{srcdir}`;
-               my ($svn_url)=$info=~/^URL: (.*)$/m;
+               my $svn_url=svn_info("URL", $config{srcdir});
 
                # FIXME: currently assumes that the wiki is somewhere
                # under trunk in svn, doesn't support other layouts.
@@ -1018,7 +1051,7 @@ sub cgi_editpage ($$) { #{{{
 
        eval q{use CGI::FormBuilder};
        my $form = CGI::FormBuilder->new(
-               fields => [qw(do from page content comments)],
+               fields => [qw(do rcsinfo from page content comments)],
                header => 1,
                method => 'POST',
                validate => {
@@ -1039,6 +1072,13 @@ sub cgi_editpage ($$) { #{{{
                error("bad page name");
        }
        $page=lc($page);
+       
+       my $file=$page.$config{default_pageext};
+       my $newfile=1;
+       if (exists $pagesources{lc($page)}) {
+               $file=$pagesources{lc($page)};
+               $newfile=0;
+       }
 
        $form->field(name => "do", type => 'hidden');
        $form->field(name => "from", type => 'hidden');
@@ -1046,6 +1086,10 @@ sub cgi_editpage ($$) { #{{{
        $form->field(name => "comments", type => "text", size => 80);
        $form->field(name => "content", type => "textarea", rows => 20,
                cols => 80);
+       if (! $form->submitted) {
+               $form->field(name => "rcsinfo", type => 'hidden',
+                       value => rcs_prepedit($file), force => 1);
+       }
        
        if ($form->submitted eq "Cancel") {
                print $q->redirect("$config{url}/".htmlpage($page));
@@ -1120,13 +1164,6 @@ sub cgi_editpage ($$) { #{{{
        }
        else {
                # save page
-               my $file=$page.$config{default_pageext};
-               my $newfile=1;
-               if (exists $pagesources{lc($page)}) {
-                       $file=$pagesources{lc($page)};
-                       $newfile=0;
-               }
-               
                my $content=$form->field('content');
                $content=~s/\r\n/\n/g;
                $content=~s/\r/\n/g;
@@ -1152,7 +1189,8 @@ sub cgi_editpage ($$) { #{{{
                        unlockwiki();
                        # presumably the commit will trigger an update
                        # of the wiki
-                       my $conflict=rcs_commit($file, $message);
+                       my $conflict=rcs_commit($file, $message,
+                               $form->field("rcsinfo"));
                
                        if (defined $conflict) {
                                $form->tmpl_param("page_conflict", 1);