- Replace is_readable() function with pre-existing readable() function

- Close Savannah bug #21202 by not assuming that file cannot be opened
even if read permissions don't indicate such.


git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup@855 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109

trunk/rdiff-backup/CHANGELOG

 New in v1.1.15 (????/??/??)
 ---------------------------
 
+Don't assume that a file cannot be read simply becasue of the access
+permissions -- eg, NFS with (rw,all_squash) options. Closes Savannah
+bug #21202. (Based on patch from Marc Horowitz)
+
 restore_set_root should check if it can read a particular directory
 before checking if "rdiff-backup-data" is contained in it. Closes
 Savannah bug #21106. (Patch from Alex Chapman)

trunk/rdiff-backup/rdiff_backup/Main.py

@@ -598,7 +598,7 @@ def restore_set_root(rpin):
 	i = len(pathcomps)
 	while i >= min_len_pathcomps:
 		parent_dir = rpath.RPath(rpin.conn, "/".join(pathcomps[:i]))
-		if (parent_dir.isdir() and parent_dir.is_readable() and
+		if (parent_dir.isdir() and parent_dir.readable() and
 			"rdiff-backup-data" in parent_dir.listdir()): break
 		if parent_dir.path == rpin.conn.Globals.get('restrict_path'):
 			return None

trunk/rdiff-backup/rdiff_backup/backup.py

@@ -202,14 +202,21 @@ class DestinationStruct:
 			log.ErrorLog.write_if_open("UpdateError", dest_rp,
 				"File changed from regular file before signature")
 			return None
-		if Globals.process_uid != 0 and not dest_rp.readable():
+		if (Globals.process_uid != 0 and not dest_rp.readable() and
+				dest_rp.isowner()):
 			# This branch can happen with root source and non-root
 			# destination.  Permissions are changed permanently, which
 			# should propogate to the diffs
-			assert dest_rp.isowner(), 'no ownership of %s' % (dest_rp.path,)
 			dest_rp.chmod(0400 | dest_rp.getperms())
-		return Rdiff.get_signature(dest_rp)
-				
+		try:
+			return Rdiff.get_signature(dest_rp)
+		except IOError, e:
+			if (e.errno == errno.EPERM):
+				log.Log.FatalError("Could not open %s for reading. Check "
+						"permissions on file." % (dest_rp.path,))
+			else:
+				raise
+
 	def patch(cls, dest_rpath, source_diffiter, start_index = ()):
 		"""Patch dest_rpath with an rorpiter of diffs"""
 		ITR = rorpiter.IterTreeReducer(PatchITRB, [dest_rpath, cls.CCPP])

trunk/rdiff-backup/rdiff_backup/rpath.py

@@ -599,10 +599,6 @@ class RORPath:
 		"""Signal that rorp is a signature/diff for a hardlink file"""
 		self.data['linked'] = index
 
-	def is_readable(self):
-		"""Check whether user can read the file or directory"""
-		return self.conn.os.access(self.path, self.conn.os.R_OK)
-
 	def open(self, mode):
 		"""Return file type object if any was given using self.setfile"""
 		if mode != "rb": raise RPathException("Bad mode %s" % mode)