bug#10047: Looking for help debugging an undo issue

[Phil Sainty]

Thank you Stefan, that's very much appreciated. (Will I find that
code in the new 24.0.92 pretest, or do I need to build from version
control?)

> 4- at the beginning of GC, the log is considered too long (because of
>     those spurious entries) and gets truncated.
> 5- at the end of GC, those spurious entries are removed from the log
>     because those markers were temporary and only the undo-log still had
>     references to them.
[...]
> - swap 4 and 5 (actually it was swapped in Emacs-22, so that would
>    revert to the behavior of Emacs-21).

I see what you mean, and yet one presumes that change was made for
a reason. Is there any indication of why that change was made?


On a related note to all of this, I found what seems like a good
question, enquiring about how to determine safe/sensible values
for increasing the undo limits, but it never got an answer. It
would be nice to see that answered:

http://lists.gnu.org/archive/html/help-gnu-emacs/2011-02/msg00112.html