bug#4312: 23.1; save-excursion and goto-char fail

[Andreas Schwab]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> 1. I have a lisp code which saves file buffer and does some
>> manipulation on the file in shell.  subsequently it is reverted.
>> However I have tried save-excursion before saving file which did not
>> restore the file position on reverting.
>
> save-excursion uses markers to remember the position.  But markers only
> keep track of positions by keeping track of insertions/deletions and
> adjusting the position accordingly.  When the changes happen outside
> Emacs, this doesn't work too well, because Emacs sees your revert-buffer
> as just one big delete&insert.

insert-file-contents tries to keep markers if possible, but that only
works if the marker points into the unchanged head or tail of the
replaced contents.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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