bug#24094: 25.1.50; revert-buffer error in CC mode

[Óscar Fuentes]

Richard Copley <rcopley@gmail.com> writes:

> Here is a recipe.
>
> Prepare a file "test0.cpp" as follows: (<<END)
> int main () {
>   int a = 0;
>   int b = 1;
>   int c = 2;
>   int d = 3;
> }
> END
>
> In a shell: cp test0.cpp test.cpp
> In Emacs: visit test.cpp, transpose "line b" and "line c", save the
> buffer, and put point between the transposed lines (i.e., at the
> beginning of "line b").
> In the shell: cp test0.cpp test.cpp
> In Emacs: revisit test.cpp (C-x f M-n RET).

Great! I can reproduce here with `emacs -Q'. It is important to note
that the `transpose' step above means `M-x transpose-lines' (or its
corresponding shorcut). Transposing with C-k <down> C-y invalidates the
recipe.