bad fixes to a higher level problem

[Wes Hardaker <wes@hardakers.net>]

So, I've had odd problems that aren't reproducible when entering a
group.  Random nil values being passed around where they shouldn't be.
I have a sneaking suspicion it's related to my use of the
gnus-summary-display-while-building variable (which I admittedly
wrote).  I'm not sure other people are using it, and the only reason I
think it might be related is because it was about the same time that I
think the problem started happening (a loooong time ago).

Upon entering a summary buffer (nnimap backend), it would occasionally
crash.  Killing the incomplete summary buffer and re-entering
immediately again and it won't crash.  That's what's really wierd.

I finally debugged the crashes enough to create a few patches to
gnus-sum.el which have merely moved the crashes to different places
every time i still see them.  Thus, I suspect something higher up is
going wrong somewhere and stuff is getting handed downward in the
stack that shouldn't.  Thoughts?

[line numbers may be off because there are other font-related patches
of mine in the same file]

@@ -10725,6 +10725,7 @@
     ;; Go forward until either the buffer ends or the subthread
     ;; ends.
     (when (and (not (eobp))
+              article
               (or (zerop (gnus-summary-next-thread 1 t))
                   (goto-char (point-max))))
       (prog1
@@ -10740,12 +10741,14 @@
   "Go to the same level (or less) next thread.
 If PREVIOUS is non-nil, go to previous thread instead.
 Return the article number moved to, or nil if moving was impossible."
-  (let ((level (gnus-summary-thread-level))
+  (let ((level (or (gnus-summary-thread-level) 0))
        (way (if previous -1 1))
-       (beg (point)))
+       (beg (point))
+       thlevel)
     (forward-line way)
     (while (and (not (eobp))
-               (< level (gnus-summary-thread-level)))
+               (setq thlevel (gnus-summary-thread-level))
+               (< level thlevel))
       (forward-line way))
     (if (eobp)
        (progn


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"In the bathtub of history the truth is harder to hold than the soap,
 and much more difficult to find."  -- Terry Pratchett