improved error handling of GroupPatterns

1 files changed, 11 insertions, 8 deletions

diff --git a/src/lib/Server/Plugins/GroupPatterns.py b/src/lib/Server/Plugins/GroupPatterns.py
index 76a628931..7733f409f 100644
--- a/src/lib/Server/Plugins/GroupPatterns.py
+++ b/src/lib/Server/Plugins/GroupPatterns.py
@@ -25,7 +25,7 @@ class PackedDigitRange(object):
 
 
 class PatternMap(object):
-    range_finder = '\\[\\[[\d\-,]+\\]\\]'
+    range_finder = r'\[\[[\d\-,]+\]\]'
 
     def __init__(self, pattern, rangestr, groups):
         self.pattern = pattern
@@ -35,15 +35,18 @@ class PatternMap(object):
             self.re = re.compile(pattern)
             self.process = self.process_re
         elif rangestr != None:
+            if '\\' in rangestr:
+                raise Exception("Backslashes are not allowed in NameRanges")
             self.process = self.process_range
-            self.re = re.compile('^' + re.subn(self.range_finder, '(\d+)',
-                                               rangestr)[0])
-            dmatcher = re.compile(re.subn(self.range_finder,
-                                          '\\[\\[([\d\-,]+)\\]\\]',
-                                          rangestr)[0])
-            self.dranges = [PackedDigitRange(x) for x in dmatcher.match(rangestr).groups()]
+            self.re = re.compile('^' + re.sub(self.range_finder, '(\d+)',
+                                              rangestr))
+            dmatcher = re.compile(re.sub(self.range_finder,
+                                         r'\[\[([\d\-,]+)\]\]',
+                                         rangestr))
+            self.dranges = [PackedDigitRange(x)
+                            for x in dmatcher.match(rangestr).groups()]
         else:
-            raise Exception
+            raise Exception("No pattern or range given")
 
     def process_range(self, name):
         match = self.re.match(name)