On 04/29/2016 03:50 PM, John Wiegley wrote:
> Hi Daniel,
> 
> I was wondering if I could ask you far the rationale behind the customization
> variable `window-adjust-process-window-size-function', and a bit more
> information about what "process buffer windows" are, and how they relate to
> process buffers, and other windows.  I don't think we have any clear rationale
> for this feature in any documented place yet.
> 

We want to communicate to subprocesses how much room they have available
to display their content. We send them this information by using
TIOCSWINSZ, which ends up generating SIGWINCH. Suppose we have a
subprocess associated with a buffer, and that buffer is displayed in two
Emacs windows, one larger than the other. Do we tell the subprocess that
it has the width of the smaller or the width of the larger available for
its output? The choice isn't immediately obvious, so it can be
configured the usual way with
window-adjust-process-window-size-function. The above discussion is
largely repeated in the docstring for that variable.