dh_insert: bad deref in chain for ...

Hi,

sometimes I get this message:
"dh_insert:bad deref in chain for <xxxxxxxxxxxxxxxx> during search"
Result: "store_local:can't insert in db for <yyyyyyyyyyyyyy>"

While I was looking for the reason I found that code snipet in dhash.c:

   while (chp != NULL)
   {
      
      ... code ...
      
      if (chp == NULL)
      {
         LOG("dh_insert:bad deref in chain for \"<%s>\" during search", dp->messageid);
         break;
      }
   }

   len = sizeof (struct chain) + strlen(dp->messageid) + 1 - sizeof (chp->messageid);

But if chp is NULL, this will end the while loop and the next
statement should segfault because of 'sizeof(chp->messageid)', shouldn't it?

I'm wondering why this doesn't break?

so long Chris
-- 
Um des Reimes willen, lasst uns einen killen.