From 9e8e92f318c6b776486ab19509326f0b470d491d Mon Sep 17 00:00:00 2001
From: Jakub Narebski <jnareb@gmail.com>
Date: Mon, 6 Dec 2010 00:01:10 +0100
Subject: [PATCH] gitweb: Wrap die_error to use as error handler for caching
 engine

Use cache_error_handler subroutine, wrapping die_error (and
HTML-escaping error message), as 'on_error' handler for
GitwebCache::SimpleFileCache and its derivatives, and as both
'on_get_error' and 'on_set_error' handler for CHI based caching
engine.

Added single test in t9501 that checks if error in caching layer
produces "500 Internal Server Error".

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---
 gitweb/gitweb.perl                       | 27 +++++++++++++++++++++++++++
 t/t9501-gitweb-standalone-http-status.sh |  8 ++++++++
 2 files changed, 35 insertions(+)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index d181ba3648..89a394320a 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -365,6 +365,20 @@ our %cache_options = (
 	# finishes within this time, then generating error pages should be safe
 	# from infinite "Generating page..." loop.
 	'generating_info_is_safe' => 1,
+
+	# How to handle runtime errors occurring during cache gets and cache
+	# sets.  Options are:
+	#  * "die" (the default) - call die() with an appropriate message
+	#  * "warn" - call warn() with an appropriate message
+	#  * "ignore" - do nothing
+	#  * <coderef> - call this code reference with an appropriate message
+	# Note that gitweb catches 'die <message>' via custom handle_errors_html
+	# handler, set via set_message() from CGI::Carp.  'warn <message>' are
+	# written to web server logs.
+	#
+	# The default is to use cache_error_handler, which wraps die_error.
+	# Only first argument passed to cache_error_handler is used (c.f. CHI)
+	'on_error' => \&cache_error_handler,
 );
 # You define site-wide options for "Generating..." page (if enabled) here
 # (which means that $cache_options{'generating_info'} is set to coderef);
@@ -1186,6 +1200,17 @@ sub configure_gitweb_features {
 	}
 }
 
+# custom error handler for caching engine (Internal Server Error)
+sub cache_error_handler {
+	my $error = shift;
+
+	$error = to_utf8($error);
+	$error =
+		"Error in caching layer: <i>".ref($cache)."</i><br>\n".
+		CGI::escapeHTML($error);
+	# die_error() would exit
+	die_error(undef, undef, $error);
+}
 # custom error handler: 'die <message>' is Internal Server Error
 sub handle_errors_html {
 	my $msg = shift; # it is already HTML escaped
@@ -1348,6 +1373,8 @@ sub configure_caching {
 			# (CHI compatibile initialization)
 			'root_dir' => $cache_options{'cache_root'},
 			'depth' => $cache_options{'cache_depth'},
+			'on_get_error' => $cache_options{'on_error'},
+			'on_set_error' => $cache_options{'on_error'},
 		});
 	}
 	unless (defined $capture && ref($capture)) {
diff --git a/t/t9501-gitweb-standalone-http-status.sh b/t/t9501-gitweb-standalone-http-status.sh
index 168e4940be..af89422c44 100755
--- a/t/t9501-gitweb-standalone-http-status.sh
+++ b/t/t9501-gitweb-standalone-http-status.sh
@@ -147,5 +147,13 @@ test_expect_success 'caching enabled (non-existent commit, 404 error)' '
 test_debug 'echo "headers" && cat gitweb.headers'
 test_debug 'echo "body"    && cat gitweb.body'
 
+test_expect_success 'caching errors are 500 Internal Server Error' '
+	chmod 0000 cache/ &&
+	test_when_finished "chmod 0777 cache/" &&
+	gitweb_run "p=.git" &&
+	grep "Status: 500 Internal Server Error" gitweb.headers &&
+	grep "500 - Internal Server Error" gitweb.body
+'
+test_debug 'echo "headers" && cat gitweb.headers'
 
 test_done
-- 
2.11.4.GIT