Print a more helpful error message when we get a "Result too large" error

git-svn-id: http://svn.savannah.nongnu.org/svn/rdiff-backup@860 2b77aa54-bcbc-44c9-a7ec-4f6cf2b41109

trunk/rdiff-backup/CHANGELOG

 New in v1.1.15 (????/??/??)
 ---------------------------
 
+Print a more helpful error message when we get a "Result too large"
+error when trying to copy a file. (Andrew Ferguson)
+
 Fix bug where rdiff-backup fails after all increments are removed. Closes
 Savannah bug #20291. (Andrew Ferguson)
 

trunk/rdiff-backup/rdiff_backup/rpath.py

@@ -125,7 +125,17 @@ def copy_reg_file(rpin, rpout, compress = 0):
 			rpout.setdata()
 			return v
 	except AttributeError: pass
-	return rpout.write_from_fileobj(rpin.open("rb"), compress = compress)
+	try:
+		return rpout.write_from_fileobj(rpin.open("rb"), compress = compress)
+	except IOError, e:
+		if (e.errno == errno.ERANGE):
+			log.Log.FatalError("'IOError - Result too large' while reading %s. "
+							   "If you are using a Mac, this is probably "
+							   "the result of HFS+ filesystem corruption. "
+							   "Please exclude this file from your backup "
+							   "before proceeding." % rpin.path)
+		else:
+			raise
 
 def cmp(rpin, rpout):
 	"""True if rpin has the same data as rpout