826         end = rev * struct.calcsize(indexformat)

   826         end = rev * struct.calcsize(indexformat)

   827         self.opener(self.indexfile, "a").truncate(end)

   827         self.opener(self.indexfile, "a").truncate(end)

   828 

   828 

   829         # then reset internal state in memory to forget those revisions

   829         # then reset internal state in memory to forget those revisions

   830         self.cache = None

   830         self.cache = None

   831         for p in self.index[rev:]:

   832         for p in self.index[rev:]:

   832             del self.nodemap[p[6]]

   833             del self.nodemap[p[6]]

   833         del self.index[rev:]

   834         del self.index[rev:]

   834 

   835 

   835         # truncating the lazyindex also truncates the lazymap.

   836         # truncating the lazyindex also truncates the lazymap.