Fixed: Make ScrollDown escape respect margins

[evg-zhabotinsky]

SD sequence (${CSI}${N}T) was scrolling the whole width
of the terminal instead of just between the margins.
RI sequence (${ESC}M, move cursor up 1 line) was doing the same. Fixed that.

Fixes #2576 where in tmux scrolling one of several
side-by-side panels down resulted in all visually scrolling.

[parisafalahzadeh]

لطفا رفع خطا را آموزش دهید

[evg-zhabotinsky]

@Fparisa166 You can install an .apk found under "checks" below. ("Details" link next to "build", then click "Summary" and under "Artifacts" find a file that matches your phone, probably termux-app_*-android-7-github-debug_universal, it's a zip with .apk inside.) This requires tha Termux.Api and others, if any, are also installed from Github releases.

Or just wait until an official update to Termux.

[evg-zhabotinsky]

Just poking, this PR hasn't been merged for over 3 months.
The changes seem trivial enough to verify, and they fix an actual problem. (See the referenced issue.)
Also, I've been using Termux with this patch semi-frequently all that time, didn't notice any issues.
Or do I need to create a new issue, because the one this PR references was (mistakenly) closed as a wontfix?

[Grimler91]

@evg-zhabotinsky I am guessing @agnostic-apollo has already merged this locally and will push it as part of the upcoming 0.119 update, considering the force-pushes above

[agnostic-apollo]

The force push was for master branch, but this pull should be mergable before next release, haven't tested it yet, will do it after I push my local changes.

[fornwall]

Thanks! I've added tests for this in ScrollRegionTest.

Seems that recent tmux versions no longer triggers this buggy (perhaps working around broken terminal emulators, as the mac terminal had the same issue), but this change indeed seems like a correct one, and aligns us with xterm and other more actively maintained terminals.