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.

5 files changed, 26 insertions, 12 deletions

diff --git a/IkiWiki/Plugin/recentchangesdiff.pm b/IkiWiki/Plugin/recentchangesdiff.pm
index bd2826f76..3942f308b 100644
--- a/IkiWiki/Plugin/recentchangesdiff.pm
+++ b/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 => $diff);
diff --git a/IkiWiki/Rcs/Stub.pm b/IkiWiki/Rcs/Stub.pm
index d94daf8bc..a460f29a2 100644
--- a/IkiWiki/Rcs/Stub.pm
+++ b/IkiWiki/Rcs/Stub.pm
@@ -60,7 +60,8 @@ sub rcs_recentchanges ($) {
 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 ($) {
diff --git a/IkiWiki/Rcs/git.pm b/IkiWiki/Rcs/git.pm
index 9306a513e..1882b43ef 100644
--- a/IkiWiki/Rcs/git.pm
+++ b/IkiWiki/Rcs/git.pm
@@ -414,16 +414,18 @@ sub rcs_recentchanges ($) { #{{{
 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 ($) { #{{{
diff --git a/IkiWiki/Rcs/svn.pm b/IkiWiki/Rcs/svn.pm
index 7bad40747..ea193e08f 100644
--- a/IkiWiki/Rcs/svn.pm
+++ b/IkiWiki/Rcs/svn.pm
@@ -219,7 +219,7 @@ sub rcs_recentchanges ($) { #{{{
 
 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 ($) { #{{{
diff --git a/IkiWiki/Rcs/tla.pm b/IkiWiki/Rcs/tla.pm
index 2890ff8c7..47579c15b 100644
--- a/IkiWiki/Rcs/tla.pm
+++ b/IkiWiki/Rcs/tla.pm
@@ -171,7 +171,7 @@ sub rcs_diff ($) { #{{{
 	}
 
 	my $revminusone = $changesets[$i+1];
-	return scalar `tla diff -d $config{srcdir} $revminusone`;
+	return `tla diff -d $config{srcdir} $revminusone`;
 } #}}}
 
 sub rcs_getctime ($) { #{{{