1 files changed, 8 insertions, 2 deletions
diff --git a/Bugzilla.pm b/Bugzilla.pm
index 8928ff8b0..621222e8a 100644
--- a/Bugzilla.pm
+++ b/Bugzilla.pm
@@ -485,8 +485,14 @@ sub usage_mode {
         }
         $class->request_cache->{usage_mode} = $newval;
     }
-    return $class->request_cache->{usage_mode}
-        || (i_am_cgi()? USAGE_MODE_BROWSER : USAGE_MODE_CMDLINE);
+
+    # XXX - Once we require Perl 5.10.1, this test can be replaced by //.
+    if (exists $class->request_cache->{usage_mode}) {
+        return $class->request_cache->{usage_mode};
+    }
+    else {
+        return (i_am_cgi()? USAGE_MODE_BROWSER : USAGE_MODE_CMDLINE);
+    }
 }
 
 sub installation_mode {