Default width is now 80

src/cdiff.py

                     yield self._markup_common(' ' + old[1])
 
     def markup_side_by_side(self, width):
-        """width of 0 means infinite width, None means auto detect. Returns a
-        generator
-        """
+        """Returns a generator"""
         def _normalize(line):
             return line.replace('\t', ' ' * 8).replace('\n', '')
 
                 return markup
 
         # Setup line width and number width
-        if not width: width = 80
+        if width <= 0:
+            width = 80
         (start, offset) = self._hunks[-1].get_old_addr()
         max1 = start + offset - 1
         (start, offset) = self._hunks[-1].get_new_addr()
     parser = optparse.OptionParser(usage)
     parser.add_option('-s', '--side-by-side', action='store_true',
             help=('show in side-by-side mode'))
-    parser.add_option('-w', '--width', type='int', default=None,
-            help='set line width (side-by-side mode only)')
+    parser.add_option('-w', '--width', type='int', default=80,
+            help='set line width (side-by-side mode only), default is 80')
     opts, args = parser.parse_args()
 
-    if opts.width and opts.width < 0:
-        opts.width = 0
-
     if len(args) >= 1:
         diff_hdl = open(args[0], 'r')
     elif sys.stdin.isatty():