Re: [RFA v2] Add "continue" response to pager

[Pedro Alves <palves@redhat.com>]

On 05/09/2018 10:28 PM, Tom Tromey wrote:
>>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:
> 
> Pedro> I gave the patch a quick try, and I have to say that it looks a
> Pedro> bit odd to me that the pager prompt takes two lines:
> 
> Pedro> ---Type <return> to continue, q <return> to quit, or c <return> to
> Pedro>    continue without paging---
> 
> Pedro> I'm wondering whether we can shorten that, to, say:
> 
> Pedro> ---Type <return> for more, q to quit, c to continue without paging---
> 
> Yeah, I think that would be better.
> 
> The Emacs docs write <RET> for return.  So maybe:
> 
> Pedro> --Type <ret> for more, q to quit, c to continue without paging--       # 64 cols
> 
> Though I guess I would tend to add a couple of spaces, so:
> 
> -- Type <RET> for more, q to quit, c to continue without paging --       # 66 cols

That's fine with me.  I suspect that the "---" wrapping without
spaces might have been inspired by some Unix /usr/bin/more
implementation, because util-linux's 'more' prints "--More-- "
by default.

> I would like to get the spelling worked out before updating the patch.
> 
> Pedro> Did you look up the patch submission, see if it still makes sense?
> 
> Nope, but if we shorten the text then perhaps the change won't be
> needed.

A racy test won't usually be an issue with size of the text, but
about how the regexps might match differently depending
on how much the expect buffer happens to get filled with.

I found the original submission, here:

  https://sourceware.org/ml/gdb-patches/2011-05/msg00150.html

which points at:

 ~~~~~~~~~~~~
 However, when using read1(), the "<return>" part matches with
 this snippet from lib/gdb.exp:
 
          "<return>" {
             send_gdb "\n"
             perror "Window too small."
             fail "$message"
             ...
 ~~~~~~~~~~~~

However, someone *cough* changed that "<return>" to
$pagination_prompt instead:

	-re "$pagination_prompt" {
	    send_gdb "\n"
	    perror "Window too small."
	    fail "$message"

in:

commit c3f814a14336b9d395f3abad739592929e2faaa0
Author:     Pedro Alves <palves@redhat.com>
AuthorDate: Fri Jul 25 10:07:38 2014 +0100

    Fix paginate-*.exp races

so it looks like the split is really no longer necessary.

A brief passage about this in the commit log would be nice,
so that we have a history link in case we need to revisit.

Please confirm that the affected tests pass cleanly with
make check-read1, just to make sure.

Thanks,
Pedro Alves