Re: Problem report #5

["Stuart D. Herring" <herring@lanl.gov>]

> 3140 	  prev = NULL;
> 3141 	  for (tail = buf->overlays_before; tail; prev = tail, tail = next)
> 3142 	    {
> 3143 	      next = tail->next;
> 3144 	      XSETMISC (overlay, tail);
> 3145
> 3146 	      /* If the overlay is not valid, get rid of it.  */
> 3147 	      if (!OVERLAY_VALID (overlay))
> [...]
> 3161
> 3162 	      beg = OVERLAY_START (overlay);
> 3163 	      end = OVERLAY_END (overlay);
> 3164
> 3165 	      if (OVERLAY_POSITION (end) > pos)
> 3166 		{
> 3167 		  /* OVERLAY needs to be moved.  */
> 3168 		  int where = OVERLAY_POSITION (beg);
> 3169 		  struct Lisp_Overlay *other, *other_prev;
> 3170
> 3171 		  /* Splice the cons cell TAIL out of overlays_before.  */
>
> Event dead_error_condition: On this path, the condition "prev != 0" could
> not be true
> Also see events: [dead_error_line][assignment][const][const][assignment]
>
> 3172 		  if (prev)

It's true that tail is never 0 within the loop (loop test), and that on
every iteration but the first prev has been assigned tail, which wasn't 0
at the time of assignment.  But on the first iteration, this test is
guaranteed to pass!  No bug.

Davis

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