bug#29111: 26.0.90; Erc keep-place module broken with new default of switch-to-buffer-preserve-window-point

[Jay Kamat]

Hi Martin,

> Can you try replacing all ‘switch-to-buffer’ calls in the erc directory
> by ‘pop-to-buffer-same-window’ calls and test whether the problem goes
> away?  I'm afraid I have no better proposal.

I tried this, and it seems to restore keep-place functionality when
switching to buffers with M-x erc-track-switch-buffer, but not with C-x
b. I suspect the call to switch-to-buffer in C-x b isn't handled by erc,
so changing the function won't help. Obviously, I don't think that's an
acceptable solution.

I can think of two solutions right now:

1. Add a new configuration option which allows keep-place mode to
disable this setting dynamically, and on enabling keep-place, add erc
buffers to the exempted list. I took a look at `switch-to-buffer' and I
don't see any way this can be done without a new variable. I personally
would like to use the new default for non-erc buffers, and I would
suspect that others would like to turn it on selectively as well.

2. Make it impossible to miss that this variable must be turned off when
keep-place is enabled. If this isn't done, people's config will silently
break (which is pretty bad). I would think that keep-place should throw
an error when this variable is t, to be safe (since it doesn't work at
all when it is).

What do you think? I would be happy if keep-place would work out of the
box for new users of erc, but I'm not sure if that's possible...

-Jay