support DECSET/DECRST (CSI ? Pm h) to change where the cursor ends up

[db48x]

after printing a sixel image. The default is for the cursor to be
moved to the first column of the line after the image. When we receive
CSI ? 8452 h, we will instead leave the cursor on the last line of the
image, on the next column past the end of the image.

[ayosec]

Hi @db48x. Thanks for the patch.

Do you have any documentation about this mode? The only reference I can find about it is the commit in xterm where it was added (in the version 303c). The changelog for version 304 doesn't mention it:

• ...
• reduce bss storage used for ReGIS/Sixel modules, as well as cleanup
  storage usage in other modules.
• initial changes for ReGIS support (Ross Combs):
  • document control-sequences
  • separate ifdef's for sixel and color-register features
  • add configuration for VT382

The reference to VT382 seems unrelated to the mode. There are no mentions to it in the VT382 programmer reference manual. In the manual, the table 11-2 (page 180) lists known modes by the terminal, and it ends at 20. Also, the (short) chapter 12, about sixel, does not mention any way to control the cursor position after adding the graphic.

---

I'm unsure about adding it if it is a private extension done in xterm. At least, until the future of the patch is decided.

[db48x]

Hi @db48x. Thanks for the patch.

Do you have any documentation about this mode? The only reference I can find about it is the commit in xterm where it was added (in the version 303c).
[…]
I'm unsure about adding it if it is a private extension done in xterm. At least, until the future of the patch is decided.

https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h3-Sixel-Graphics:CSI-?-Pm-h.92F

It allows printing graphics near the bottom of the window without getting an extra empty line below the graphics. It may be an xterm extension, but at this point xterm is the primary reference for what sixel support looks like.

I don’t believe that it is related to VT382 either. (I’m not even sure what a VT382 is; I’ve never heard of one before).

[dankamongmen]

sorry about the comment just posted here; it was intended for another issue =[ how embarrassing

[ayosec]

Sorry for the delay @db48x.

I tested it and everything seems fine. Thanks for the patch.