Try chmod'ing again if we can't open a file -- let's rdiff-backup work

better in some AFS and NFS installs.


git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup@878 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109

trunk/rdiff-backup/CHANGELOG

 New in v1.1.16 (????/??/??)
 ---------------------------
 
+Don't give up right away if we can't open a file. Try chmod'ing it even
+if we aren't root or don't own it, since that can sometimes work on AFS
+and NFS. Closes Savannah bug #21202. (Andrew Ferguson)
+
 Correctly handle updates to nested directories with unreadable permissions.
 Thanks to John Goerzen for the bug report. Closes Debian bugs #389134 and
 #411849. (Andrew Ferguson)

trunk/rdiff-backup/rdiff_backup/backup.py

@@ -212,7 +212,14 @@ class DestinationStruct:
 			return Rdiff.get_signature(dest_rp)
 		except IOError, e:
 			if (e.errno == errno.EPERM):
-				log.Log.FatalError("Could not open %s for reading. Check "
+				try:
+					# Try chmod'ing anyway -- This can work on NFS and AFS
+					# depending on the setup. We keep the if() statement
+					# above for performance reasons.
+					dest_rp.chmod(0400 | dest_rp.getperms())
+					return Rdiff.get_signature(dest_rp)
+				except (IOError, OSError):
+					log.Log.FatalError("Could not open %s for reading. Check "
 						"permissions on file." % (dest_rp.path,))
 			else:
 				raise