Hi Thomas,
On Fri, 6 Apr 2018, Thomas Wolff wrote:
Am 06.04.2018 um 12:31 schrieb Johannes Schindelin:
On Fri, 6 Apr 2018, Thomas Wolff wrote:
These symptoms suggest to me: winpty is not the culprit, but its
presence in the invocation chain seems to trigger the effect in a
yet unclear way.
Sure, `winpty` is not the culprit.
Actually, as it turns out, winpty *is* the culprit. I've raised winpty
issue https://github.com/rprichard/winpty/issues/140 about it.
I am not sure you understand the issue here. The `winpty` helper opens a
Win32 console for the native Windows application to use. Then it polls
this (hidden) console for changes and tries to reflect them in the Cygwin
pty.
If that Windows application writes something to that console containing
Escape sequences, then those Escape sequences occupy certain cells in that
matrix of rows and columns making up that console.
However, if the Windows application uses random-access functions to put
individual characters into cells specified by given absolute positions,
winpty cannot tell the difference. So what winpty would be asked to
consider an ANSI sequence may never have been an ANSI sequence.
Sure, this is a construed example, but it shows that you should not be so
sure that winpty *can* detect ANSI sequences and handle them in a way that
*you* want.
[...]
In the least, therefore, it should be configurable. And I would even argue
that the default behavior should remain the same as current in Cygwin: do
not use winpty by default.
Of course, this is just my opinion, and I am but a user and infrequent
contributor to Cygwin. But I would hope that the Cygwin maintainers use a
lot of care and reluctant deliberation when considering a potentially
disruptive change such as this, a change that may very well occupy a lot
of time in dealing with the unwanted fallout.