bug#13949: 24.4.1; `fill-paragraph' should not always put the buffer as modified

[Óscar Fuentes]

Lars Magne Ingebrigtsen <larsi@gnus.org> writes:

> Óscar Fuentes <ofv@wanadoo.es> writes:
>
>> I don't think so. It could be auto-disabled for large buffers and the
>> check would only take place when the size of the buffer is the same as
>> the size of the original file.
>
> Oh yeah, that's true...  Except for the problem with the text
> properties.  :-)

Oh yes, apparently the fix for this bug must be bug-compatible with the
feature it is fixing.

>> Then, the hash would be calculated on a idle timer that is fired after
>> a command that changes the contents...
>
> I think I'd want the "buffer changed" indicator to reflect the state
> immediately after doing an edit, though.  It's been a long-standing
> annoyance that Emacs claims that the buffer is changed when it "kinda
> isn't" (i.e., insert "a" and then delete it).  I want to see that
> immediately in the mode line.

Agreed. As long as the file is small enough for the hash function, an
idle timer with a short span would do. We don't want the hashing running
again and again while some command does multiple changes to the buffer.