[PATCH 4/5] gitweb: Add custom error handler using die_error
Change the default message for errors (for fatalsToBrowser) to use die_error() subroutine. This way errors (and explicitely calling 'die MESSAGE') would generate 'Internal Server Error' error message.
Note that call to set_message is intentionally not put in BEGIN block; we set error handler to use die_error() only after we are sure that we can use it, after all needed variables are set.
Due to the fact that error handler set via set_message() subroutine from CGI::Carp (in the fatalsToBrowser case) is called after HTTP headers were already printed (with exception of MOD_PERL), gitweb cannot return 'Status: 500 Internal Server Error'.
Thanks to the fact that die_error() no longer uses 'exit', errors would be logged by CGI::Carp, independent on whether default error handler is used, or handle_errors_html which uses die_error is used.
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---
Because of the fact that with CGI::Carp::set_message and die_error
you cannot return proper HTTP status code, I have decided that
caching engine needs support for custom error handler anyway, a la
'on_get_error' and 'on_set_error' in CHI.
With this patch most error messages, from fatal errors in gitweb or Perl, should get look of the rest of gitweb. This is good idea even without caching support.
gitweb/gitweb.perl | 27 +++++++++++++++++++++++----
1 files changed, 23 insertions(+), 4 deletions(-)
Show changes to gitweb/gitweb.perl +23 −4
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index ed92dca..e579c14 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -11,7 +11,7 @@ use strict;
use warnings;
use CGI qw(:standard :escapeHTML -nosticky);
use CGI::Util qw(unescape);
-use CGI::Carp qw(fatalsToBrowser);
+use CGI::Carp qw(fatalsToBrowser set_message);
use Encode;
use Fcntl ':mode';
use File::Find qw();
@@ -952,6 +952,21 @@ if ($git_avatar eq 'gravatar') {
$git_avatar = '';
}
+# custom error handler: 'die <message>' is Internal Server Error
+sub handle_errors_html {
+ my $msg = shift; # it is already HTML escaped
+
+ # to avoid infinite loop where error occurs in die_error,
+ # change handler to default handler, disabling handle_errors_html
+ set_message("Error occured when inside die_error:\n$msg");
+
+ # you cannot jump out of die_error when called as error handler;
+ # the subroutine set via CGI::Carp::set_message is called _after_
+ # HTTP headers are already written, so it cannot write them itself
+ die_error(undef, undef, $msg, -error_handler => 1, -no_http_header => 1);
+}
+set_message(\&handle_errors_html);
+
# dispatch
if (!defined $action) {
if (defined $hash) {
@@ -3167,6 +3182,7 @@ sub blob_contenttype {
sub git_header_html {
my $status = shift || "200 OK";
my $expires = shift;
+ my %opts = @_;
my $title = "$site_name";
if (defined $project) {
@@ -3194,7 +3210,8 @@ sub git_header_html {
$content_type = 'text/html';
}
print $cgi->header(-type=>$content_type, -charset => 'utf-8',
- -status=> $status, -expires => $expires);
+ -status=> $status, -expires => $expires)
+ unless ($opts{'-no_http_headers'});
my $mod_perl_version = $ENV{'MOD_PERL'} ? " $ENV{'MOD_PERL'}" : '';
print <<EOF;
<?xml version="1.0" encoding="utf-8"?>
@@ -3411,6 +3428,7 @@ sub die_error {
my $status = shift || 500;
my $error = esc_html(shift) || "Internal Server Error";
my $extra = shift;
+ my %opts = @_;
my %http_responses = (
400 => '400 Bad Request',
@@ -3419,7 +3437,7 @@ sub die_error {
500 => '500 Internal Server Error',
503 => '503 Service Unavailable',
);
- git_header_html($http_responses{$status});
+ git_header_html($http_responses{$status}, undef, %opts);
print <<EOF;
<div class="page_body">
<br /><br />
@@ -3433,7 +3451,8 @@ EOF
print "</div>\n";
git_footer_html();
- goto DONE_GITWEB;
+ goto DONE_GITWEB
+ unless ($opts{'-error_handler'});
}
## ----------------------------------------------------------------------
Jakub Narebski