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.

2 files changed, 9 insertions, 3 deletions

diff --git a/patchtracker/DiffGzHandler.py b/patchtracker/DiffGzHandler.py
index 1f1c1de..96d862b 100644
--- a/patchtracker/DiffGzHandler.py
+++ b/patchtracker/DiffGzHandler.py
@@ -3,6 +3,9 @@ import sys
 import os
 from Patch import Patch, PatchSeries
 
+class DiffGzException(Exception):
+  pass
+
 class DiffGzHandler:
   diff = None
   def __init__(self,fname):
@@ -21,7 +24,7 @@ class DiffGzHandler:
     p = Patch(o)
     err = e.read()
     if len(err):
-      raise Exception("filterdiff gave errors:",err)
+      raise DiffGzException("filterdiff gave errors: "+err)
     return p
 
   def debiandir(self):
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()