relax banner delimiter handling

ciscoconfparse/ciscoconfparse.py

@@ -1510,25 +1510,40 @@ def _mark_banner(self, banner_str, os):
         start_banner = False
         end_banner = False
         ii = 0
+
+        ### not sure if this is a sane default but it matches assumptions below
+        banner_delimiter = self.comment_delimiter
+
         if (os=="ios"):
             prefix = ""
         elif (os=="catos"):
             prefix = "set "
         else:
             raise RuntimeError("FATAL: _mark_banner(): received " + \
                 "an invalid value for 'os'")
+
+        matchpattern = prefix + "banner\s+" + banner_str+"\s+(\^*\S)"
+
         while (start_banner is False) & (ii < len(self._list)):
-            if re.search(prefix+"banner\s+"+banner_str+"\s+\^\S+", \
-                self._list[ii].text):
-                # Found the start banner at ii
-                start_banner = True
-                kk = ii + 1
+
+            matchobject = re.match(matchpattern, self._list[ii].text)
+            if matchobject:
+              ### escape any leading ^
+              if matchobject.group(1)[0] == "^":
+                banner_delimiter = "\{0}".format(matchobject.group(1))
+              else:
+                banner_delimiter = matchobject.group(1)
+
+              kk = ii + 1
+              start_banner = True
+
             else:
-                ii += 1
+              ii += 1
 
         if (start_banner is True):
             while (end_banner is False) & (kk < len(self._list)):
-                if  self._list[kk].is_comment:
+                ### .match searches from beginning so no need to ^-ify
+                if re.match(banner_delimiter,self._list[kk].text):
                     # Note: We are depending on a "!" after the banner... why
                     #       can't a normal regex work with IOS banners!?
                     #       Therefore the endpoint is at ( kk - 1)