* Many changes to make ikiwiki very resistant to write failures

  including out of disk space situations. ikiwiki should never leave
  truncated files, and if the error occurs during a web-based file edit,
  the user will be given an opportunity to retry.
  Inspired by the many ways Moin Moin destroys itself when out of disk. :-)
* Fix syslogging of errors.

3 files changed, 29 insertions, 15 deletions

diff --git a/IkiWiki/Plugin/aggregate.pm b/IkiWiki/Plugin/aggregate.pm
index 7fceb0df3..a6f850236 100644
--- a/IkiWiki/Plugin/aggregate.pm
+++ b/IkiWiki/Plugin/aggregate.pm
@@ -153,8 +153,11 @@ sub loadstate () { #{{{
 sub savestate () { #{{{
 	eval q{use HTML::Entities};
 	error($@) if $@;
-	open (OUT, ">$config{wikistatedir}/aggregate" ||
-		die "$config{wikistatedir}/aggregate: $!");
+	my $newfile="$config{wikistatedir}/aggregate.new";
+	# TODO: This cleanup function could use improvement. Any newly
+	# aggregated files are left behind unrecorded, and should be deleted.
+	my $cleanup = sub { unlink($newfile) };
+	open (OUT, ">$newfile") || error("open $newfile: $!", $cleanup);
 	foreach my $data (values %feeds, values %guids) {
 		if ($data->{remove}) {
 			if ($data->{name}) {
@@ -188,9 +191,11 @@ sub savestate () { #{{{
 				push @line, "$field=".$data->{$field};
 			}
 		}
-		print OUT join(" ", @line)."\n";
+		print OUT join(" ", @line)."\n" || error("write $newfile: $!", $cleanup);
 	}
-	close OUT;
+	close OUT || error("save $newfile: $!", $cleanup);
+	rename($newfile, "$config{wikistatedir}/aggregate") ||
+		error("rename $newfile: $!", $cleanup);
 } #}}}
 
 sub expire () { #{{{
diff --git a/IkiWiki/Plugin/passwordauth.pm b/IkiWiki/Plugin/passwordauth.pm
index 6d395324e..e0aa72a19 100644
--- a/IkiWiki/Plugin/passwordauth.pm
+++ b/IkiWiki/Plugin/passwordauth.pm
@@ -187,7 +187,8 @@ sub formbuilder (@) { #{{{
 			my $user_name=$form->field('name');
 	                foreach my $field (qw(password)) {
         	                if (defined $form->field($field) && length $form->field($field)) {
-					IkiWiki::userinfo_set($user_name, $field, $form->field($field)) || error("failed to set $field");
+					IkiWiki::userinfo_set($user_name, $field, $form->field($field)) ||
+						error("failed to set $field");
 	                        }
 	                }
 		}
diff --git a/IkiWiki/Plugin/search.pm b/IkiWiki/Plugin/search.pm
index 1b5c66716..d35c33e76 100644
--- a/IkiWiki/Plugin/search.pm
+++ b/IkiWiki/Plugin/search.pm
@@ -89,14 +89,20 @@ sub estcfg () { #{{{
 	my $estdir="$config{wikistatedir}/hyperestraier";
 	my $cgi=IkiWiki::basename($config{cgiurl});
 	$cgi=~s/\..*$//;
-	open(TEMPLATE, ">:utf8", "$estdir/$cgi.tmpl") ||
-		error("write $estdir/$cgi.tmpl: $!");
+
+	my $newfile="$estdir/$cgi.tmpl.new";
+	my $cleanup = sub { unlink($newfile) };
+	open(TEMPLATE, ">:utf8", $newfile) || error("open $newfile: $!", $cleanup);
 	print TEMPLATE IkiWiki::misctemplate("search", 
 		"<!--ESTFORM-->\n\n<!--ESTRESULT-->\n\n<!--ESTINFO-->\n\n",
-		baseurl => IkiWiki::dirname($config{cgiurl})."/");
-	close TEMPLATE;
-	open(TEMPLATE, ">$estdir/$cgi.conf") ||
-		error("write $estdir/$cgi.conf: $!");
+		baseurl => IkiWiki::dirname($config{cgiurl})."/") ||
+			error("write $newfile: $!", $cleanup);
+	close TEMPLATE || error("save $newfile: $!", $cleanup);
+	rename($newfile, "$estdir/$cgi.tmpl") ||
+		error("rename $newfile: $!", $cleanup);
+	
+	$newfile="$estdir/$cgi.conf";
+	open(TEMPLATE, ">$newfile") || error("open $newfile: $!", $cleanup);
 	my $template=template("estseek.conf");
 	eval q{use Cwd 'abs_path'};
 	$template->param(
@@ -105,13 +111,15 @@ sub estcfg () { #{{{
 		destdir => abs_path($config{destdir}),
 		url => $config{url},
 	);
-	print TEMPLATE $template->output;
-	close TEMPLATE;
+	print TEMPLATE $template->output || error("write $newfile: $!", $cleanup);
+	close TEMPLATE || error("save $newfile: $!", $cleanup);
+	rename($newfile, "$estdir/$cgi.conf") ||
+		error("rename $newfile: $!", $cleanup);
+
 	$cgi="$estdir/".IkiWiki::basename($config{cgiurl});
 	unlink($cgi);
 	my $estseek = defined $config{estseek} ? $config{estseek} : '/usr/lib/estraier/estseek.cgi';
-	symlink($estseek, $cgi) ||
-		error("symlink $estseek $cgi: $!");
+	symlink($estseek, $cgi) || error("symlink $estseek $cgi: $!");
 } # }}}
 
 sub estcmd ($;@) { #{{{