truncate recentchangesdiffs after 200 lines

This works around a perl crasher bug, and also avoids bloating pages
with enormous diffs.

rcs_recentchanges modified to return a list in an array context.

IkiWiki/Plugin/recentchangesdiff.pm

@@ -5,6 +5,8 @@ use warnings;
 use strict;
 use IkiWiki 2.00;
 
+my $maxlines=200;
+
 sub import { #{{{
 	hook(type => "pagetemplate", id => "recentchangesdiff",
 		call => \&pagetemplate);
@@ -15,8 +17,17 @@ sub pagetemplate (@) { #{{{
 	my $template=$params{template};
 	if ($config{rcs} && exists $params{rev} && length $params{rev} &&
 	    $template->query(name => "diff")) {
-		my $diff=IkiWiki::rcs_diff($params{rev});
-		if (defined $diff && length $diff) {
+		my @lines=IkiWiki::rcs_diff($params{rev});
+		if (@lines) {
+			my $diff;
+			if (@lines > $maxlines) {
+				# only include so many lines of diff
+				$diff=join("", @lines[0..($maxlines-1)])."\n".
+					gettext("(Diff truncated)");
+			}
+			else {
+				$diff=join("", @lines);
+			}
 			# escape links and preprocessor stuff
 			$diff =~ s/(?<!\\)\[\[/\\\[\[/g;
 			$template->param(diff => $diff);

IkiWiki/Rcs/Stub.pm

@@ -60,7 +60,8 @@ sub rcs_recentchanges ($) {
 sub rcs_diff ($) {
 	# Optional, used to get diffs for recentchanges.
 	# The parameter is the rev from rcs_recentchanges.
-	return "";
+	# Should return a list of lines of the diff (including \n) in list
+	# context, and the whole diff in scalar context.
 }
 
 sub rcs_getctime ($) {

IkiWiki/Rcs/git.pm

@@ -414,16 +414,18 @@ sub rcs_recentchanges ($) { #{{{
 sub rcs_diff ($) { #{{{
 	my $rev=shift;
 	my ($sha1) = $rev =~ /^($sha1_pattern)$/; # untaint
-	my $ret;
+	my @lines;
 	foreach my $line (run_or_non("git", "show", $sha1)) {
-		if (defined $ret) {
-			$ret.=$line."\n";
-		}
-		elsif ($line=~/^diff --git/) {
-			$ret=$line."\n";
+		if (@lines || $line=~/^diff --git/) {
+			push @lines, $line."\n";
 		}
 	}
-	return $ret;
+	if (wantarray) {
+		return @lines;
+	}
+	else {
+		return join("", @lines);
+	}
 } #}}}
 
 sub rcs_getctime ($) { #{{{

IkiWiki/Rcs/svn.pm

@@ -219,7 +219,7 @@ sub rcs_recentchanges ($) { #{{{
 
 sub rcs_diff ($) { #{{{
 	my $rev=possibly_foolish_untaint(int(shift));
-	return scalar `svnlook diff $config{svnrepo} -r$rev --no-diff-deleted`;
+	return `svnlook diff $config{svnrepo} -r$rev --no-diff-deleted`;
 } #}}}
 
 sub rcs_getctime ($) { #{{{

IkiWiki/Rcs/tla.pm

@@ -171,7 +171,7 @@ sub rcs_diff ($) { #{{{
 	}
 
 	my $revminusone = $changesets[$i+1];
-	return scalar `tla diff -d $config{srcdir} $revminusone`;
+	return `tla diff -d $config{srcdir} $revminusone`;
 } #}}}
 
 sub rcs_getctime ($) { #{{{

doc/bugs/recentchangesdiff_crashes_on_commits_which_remove_a_lot_of_files.mdwn

@@ -23,3 +23,24 @@ The tarball is at http://scratch.madduck.net/__tmp__recentchanges-segfault.tgz -
     rm -rf wc/recentchanges
     ikiwiki --setup ikiwiki.setup
     # works
+
+> I can reproduce it fine with that, thanks, and it's really looking like a
+> pure perl bug, that is triggered by markdown. Here's a simpler test case:
+
+	joey@kodama:/tmp>markdown < f
+	zsh: segmentation fault  markdown < f
+
+> Where f is a 6.3 mb file that I
+> extracted from ikiwiki's rendering pipeline.
+
+> It seems to be crashing at markdown line 345, which is a big nasty
+> `s///` statement.
+
+> The good news: markdown version 1.0.2~b8-2 does not trigger this perl bug.
+> I only see it with 1.0.1. (Bad news: Newer versions of markdown are
+> slooooooow, especially on such large files.)
+
+> I'm calling this [[done]] since I've filed [[debbug 470676]] on perl, and
+> also have modified recentchangesdiff to only show the first 200 lines of
+> diff, which should be enough without bloating the recentchanges into
+> perl-crashing territory. --[[Joey]]

po/ikiwiki.pot

@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2008-03-12 13:53-0400\n"
+"POT-Creation-Date: 2008-03-12 15:42-0400\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -40,30 +40,30 @@ msgstr ""
 msgid "Preferences saved."
 msgstr ""
 
-#: ../IkiWiki/CGI.pm:291
+#: ../IkiWiki/CGI.pm:293
 #, perl-format
 msgid "%s is not an editable page"
 msgstr ""
 
-#: ../IkiWiki/CGI.pm:384 ../IkiWiki/Plugin/brokenlinks.pm:24
+#: ../IkiWiki/CGI.pm:385 ../IkiWiki/Plugin/brokenlinks.pm:24
 #: ../IkiWiki/Plugin/inline.pm:237 ../IkiWiki/Plugin/opendiscussion.pm:17
 #: ../IkiWiki/Plugin/orphans.pm:28 ../IkiWiki/Render.pm:95
 #: ../IkiWiki/Render.pm:172
 msgid "discussion"
 msgstr ""
 
-#: ../IkiWiki/CGI.pm:440
+#: ../IkiWiki/CGI.pm:441
 #, perl-format
 msgid "creating %s"
 msgstr ""
 
-#: ../IkiWiki/CGI.pm:458 ../IkiWiki/CGI.pm:476 ../IkiWiki/CGI.pm:486
-#: ../IkiWiki/CGI.pm:520 ../IkiWiki/CGI.pm:564
+#: ../IkiWiki/CGI.pm:459 ../IkiWiki/CGI.pm:477 ../IkiWiki/CGI.pm:487
+#: ../IkiWiki/CGI.pm:521 ../IkiWiki/CGI.pm:566
 #, perl-format
 msgid "editing %s"
 msgstr ""
 
-#: ../IkiWiki/CGI.pm:653
+#: ../IkiWiki/CGI.pm:656
 msgid "You are banned."
 msgstr ""
 
@@ -500,7 +500,7 @@ msgstr ""
 msgid "code includes disallowed latex commands"
 msgstr ""
 
-#: ../IkiWiki/Plugin/teximg.pm:96
+#: ../IkiWiki/Plugin/teximg.pm:88
 msgid "failed to generate image from code"
 msgstr ""
 
@@ -508,7 +508,7 @@ msgstr ""
 msgid "(not toggleable in preview mode)"
 msgstr ""
 
-#: ../IkiWiki/Rcs/Stub.pm:68
+#: ../IkiWiki/Rcs/Stub.pm:69
 msgid "getctime not implemented"
 msgstr ""