Bug 739153: fix infinite recursion in error handler

2 files changed, 69 insertions, 27 deletions

diff --git a/Bugzilla/Arecibo.pm b/Bugzilla/Arecibo.pm
index 54458cca2..92c99c399 100644
--- a/Bugzilla/Arecibo.pm
+++ b/Bugzilla/Arecibo.pm
@@ -228,39 +228,76 @@ sub _in_eval {
     return $in_eval;
 }
 
-BEGIN {
-    require CGI::Carp;
-    CGI::Carp::set_die_handler(sub {
-        return if _in_eval();
-        my $message = shift;
-        my $is_compilation_failure = $message =~ /\bcompilation (aborted|failed)\b/i;
-        if (!$is_compilation_failure) {
-            eval { Bugzilla::Error::ThrowTemplateError($message) };
-        }
-        if ($is_compilation_failure || $@) {
-            print "Content-type: text/html\n\n";
-            my $uid = arecibo_generate_id();
-            my $notified = arecibo_handle_error('error', $message, $uid);
-            my $maintainer = html_quote(Bugzilla->params->{'maintainer'});
-            $message = html_quote($message);
-            $uid = html_quote($uid);
+sub _arecibo_die_handler {
+    my $message = shift;
+    $message =~ s/^undef error - //;
+
+    # avoid recursion, and check for CGI::Carp::die failures
+    my $in_cgi_carp_die = 0;
+    for (my $stack = 1; my $sub = (caller($stack))[3]; $stack++) {
+        return if $sub =~ /:_arecibo_die_handler$/;
+        $in_cgi_carp_die = 1 if $sub =~ /CGI::Carp::die$/;
+    }
+
+    return if _in_eval();
+    
+    # mod_perl overrides exit to call die with this string
+    exit if $message =~ /\bModPerl::Util::exit\b/;
+
+    my $nested_error = '';
+    my $is_compilation_failure = $message =~ /\bcompilation (aborted|failed)\b/i;
+
+    # if we are called via CGI::Carp::die chances are something is seriously
+    # wrong, so skip trying to use ThrowTemplateError
+    if (!$in_cgi_carp_die && !$is_compilation_failure) {
+        eval { Bugzilla::Error::ThrowTemplateError($message) };
+        $nested_error = $@ if $@;
+    }
+
+    # right now it's hard to determine if we've already returned a content-type
+    # header, it's better to return two than none
+    print "Content-type: text/html\n\n";
+
+    if ($is_compilation_failure ||
+        $in_cgi_carp_die ||
+        ($nested_error && $nested_error !~ /\bModPerl::Util::exit\b/)
+    ) {
+        $nested_error = html_quote($nested_error);
+        my $uid = arecibo_generate_id();
+        my $notified = arecibo_handle_error('error', $message, $uid);
+        my $maintainer = html_quote(Bugzilla->params->{'maintainer'});
+        $message =~ s/ at \S+ line \d+\.\s*$//;
+        $message = html_quote($message);
+        $uid = html_quote($uid);
+        print qq(
+            <h1>Bugzilla has suffered an internal error</h1>
+            <pre>$message</pre>
+            <hr>
+            <pre>$nested_error</pre>
+        );
+        if ($notified) {
             print qq(
-                <h1>Bugzilla has suffered an internal error</h1>
-                <pre>$message</pre>
+                The <a href="mailto:$maintainer">Bugzilla maintainers</a> have
+                been notified of this error [#$uid].
             );
-            if ($notified) {
-                print qq(
-                    The <a href="mailto:$maintainer">Bugzilla maintainers</a> have
-                    been notified of this error [#$uid].
-                );
-            };
-            exit;
-        }
-    });
+        };
+    }
+    exit;
+}
+
+sub install_arecibo_handler {
+    require CGI::Carp;
+    CGI::Carp::set_die_handler(\&_arecibo_die_handler);
     $main::SIG{__WARN__} = sub {
         return if _in_eval();
         arecibo_handle_error('warning', shift);
     };
 }
 
+BEGIN {
+    if ($ENV{SCRIPT_NAME} || $ENV{MOD_PERL}) {
+        install_arecibo_handler();
+    }
+}
+
 1;
diff --git a/Bugzilla/Error.pm b/Bugzilla/Error.pm
index c2fcfdd55..df03dfd6d 100644
--- a/Bugzilla/Error.pm
+++ b/Bugzilla/Error.pm
@@ -192,11 +192,16 @@ sub ThrowTemplateError {
         die("error: template error: $template_err");
     }
 
+    # mod_perl overrides exit to call die with this string
+    # we never want to display this to the user
+    exit if $template_err =~ /\bModPerl::Util::exit\b/;
+
     $vars->{'template_error_msg'} = $template_err;
     $vars->{'error'} = "template_error";
 
     $vars->{'uid'} = arecibo_generate_id();
     arecibo_handle_error('error', $template_err, $vars->{'uid'});
+    $vars->{'template_error_msg'} =~ s/ at \S+ line \d+\.\s*$//;
 
     my $template = Bugzilla->template;