fail more gracefully if a diff.gz is missing

this should never happen in production as the database contains
only a cache of what's on disk, but during testing on a system with
the database and no archive, or in unexpected circumstances, it
might be helpful to give a more informative error page.

1 files changed, 5 insertions, 2 deletions

diff --git a/patchtracker/ReqHandler.py b/patchtracker/ReqHandler.py
index a41114f..a87fd68 100755
--- a/patchtracker/ReqHandler.py
+++ b/patchtracker/ReqHandler.py
@@ -6,7 +6,7 @@ import sys
 
 import patchtracker.Conf as Conf
 from patchtracker.Templates import ErrorTemplate, PatchTemplate, PackageVersTemplate, LetterTocTemplate, FrontPageTemplate, SearchResultsTemplate
-from patchtracker.DiffGzHandler import DiffGzHandler
+from patchtracker.DiffGzHandler import DiffGzHandler, DiffGzException
 import patchtracker.DB as DB
 from patchtracker.DB import PatchTrackerDB
 import pygments
@@ -182,4 +182,7 @@ class CmdHandler:
     self.status = self.cmd.status
 
   def output(self):
-    return self.cmd.output()
+    try:
+      return self.cmd.output()
+    except DiffGzException, e:
+      return ErrorCmd(str(e), "500 Oh Noez!!1!").output()