trac should response 404 not found instead of 500 when files is not found

[moo]

sample urls svn file: ​http://trac.lighttpd.net/trac/browser/branches/lighttpd-1.4.11-ssl-fixes/doc/configuration.txt attachment file: ​http://trac.lighttpd.net/trac/attachment/ticket/44/trac.lighttpd.net/trac/attachment/ticket/443/phbs2.html?format=raw

[Christian Boos]

We should introduce a MissingResource error, subclass of TracError and from which NoSuchNode would inherit. The attachment code, ticket module etc. can raise the former directly.

[Christopher Lenz]

Why not just make the versioncontrol UI components catch NoSuchXxx and in turn raise HttpNotFound for now? I don't see why we need another exception layer there.

[Christian Boos]

Well, raising MissingResource looks like a good intermediate between the catch-all TracError and the Web specific HTTPNotFound, so that we could do:

trac/web/main.py

@@ -260 +260 @@
                     raise err[0], err[1], err[2]
             except PermissionError, e:
                 raise HTTPForbidden(to_unicode(e))
+            except MissingResource, e:
+                raise HTTPNotFound(e.message)
             except TracError, e:
                 raise HTTPInternalError(e.message)
         finally:

[sid <sid.wiesner@…>]

This is related to #2118, a ticket to use proper HTTP status codes.

[Christian Boos]

See also #4518. The corresponding fix (r5554) implements the idea above (ResourceNotFound instead of MissingResource).

There's now a 404 for files not found in the browser, but this is not yet done for missing attachments.

[Christian Boos]

Implemented in r5629.