termux incorrectly limits cursor movement to scroll region

[nicm]

Hi

termux 0.80 on Android.

DECSTBM should only limit scrolling not cursor movement. Compare this in xterm and in termux (the xxx should be above the aaa):

printf '\033[4;7r\033[3;1Haaa\033[Axxx' 

Cursor movement should not be affected by the scroll region but termux appears to be forcing the cursor inside the region. I suspect this should be 0 rather than mTopMargin:

termux-app/terminal-emulator/src/main/java/com/termux/terminal/TerminalEmulator.java

Line 1379 in e5a8c0e

setCursorRow(Math.max(mTopMargin, mCursorRow - getArg0(1)));

And similarly for CUD.

[nicm]

Here is termux:

[nicm]

And here is xterm:

[fornwall]

Thanks a lot for a good explanation and small test case!

Should be fixed by cdccc2c, which is now released in version 0.82 of the app.

Do you know if it's the same with DECSLRM right and left margins and CUF&CUB?

[nicm]

No, I didn't realise this before but it seems like left and right margins work differently and /do/ limit at least CUF, CUB, LF. Try this for example in xterm:

printf '\033[?69h\033[10;20s\033[1;10Ha\033[3Db\r\nc'
sleep 10

CUP and HPA are not affected.