Arranging for windows of particular dimensions in xdisp-tests

Arranging for windows of particular dimensions in xdisp-tests

[Po Lu]

I've just fixed several hangs in redisplay arising from `display'
objects' being denied sufficient space by a line or wrap prefix, and
consequently continuation lines being produced in an endless cycle
inside move_it_to and display_line.  Needless to say, tests for such
bugs require that the windows where they execute be set to a particular
size, which, considering that ERT tests are expected to run in both
interactive sessions and in the initial frame, appears to be impossible.

Ideas?  Thanks in advance.

Re: Arranging for windows of particular dimensions in xdisp-tests

[Jim Porter]

On 1/30/2024 10:26 PM, Po Lu wrote:
> I've just fixed several hangs in redisplay arising from `display'
> objects' being denied sufficient space by a line or wrap prefix, and
> consequently continuation lines being produced in an endless cycle
> inside move_it_to and display_line.  Needless to say, tests for such
> bugs require that the windows where they execute be set to a particular
> size, which, considering that ERT tests are expected to run in both
> interactive sessions and in the initial frame, appears to be impossible.
> 
> Ideas?  Thanks in advance.

The easiest might be to skip the test when it can't be run (or fail the 
test if you want to be noisier about it).

I suppose you could also spawn a second, entirely-separate Emacs 
instance to test this part, although I'm not sure I'd *recommend* doing 
that. In theory though, you could start up that second Emacs and pass it 
a script to run, exiting with zero if the test succeeded.

Re: Arranging for windows of particular dimensions in xdisp-tests

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Date: Wed, 31 Jan 2024 14:26:15 +0800
> 
> I've just fixed several hangs in redisplay arising from `display'
> objects' being denied sufficient space by a line or wrap prefix, and
> consequently continuation lines being produced in an endless cycle
> inside move_it_to and display_line.  Needless to say, tests for such
> bugs require that the windows where they execute be set to a particular
> size, which, considering that ERT tests are expected to run in both
> interactive sessions and in the initial frame, appears to be impossible.
> 
> Ideas?  Thanks in advance.

Our capabilities for testing display code in batch mode are very
limited, almost nonexistent.  So I suggest to add these tests to
test/manual/redisplay-testsuite.el instead -- those can only be run
interactively.

Re: Arranging for windows of particular dimensions in xdisp-tests

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

> Our capabilities for testing display code in batch mode are very
> limited, almost nonexistent.  So I suggest to add these tests to
> test/manual/redisplay-testsuite.el instead -- those can only be run
> interactively.

Right, thanks.