First-cut patch for mouse-face handling on tab-bar items.  I left the default handling code in place not being sure what it really is intended to do (which appears to be nothing?).  It looks copied from note_tool_bar_highlight but I wasn't sure.  (xdisp internals are fun.  It's a work of art.)

-Stephane

On Tue, Feb 18, 2025 at 12:14 PM Juri Linkov <juri@linkov.net> wrote:

> I was trying to make a simple aesthetic change to tab-bar to highlight a
> tab when it is moused over. mouse-face seems to work in tab-line,
> header-line, and obviously in mode-line. Mouse events are processed in the
> tab-bar window. Am I missing something obvious? I tested in 29.4 and in
> master.

Indeed, this would be a nice feature. Patches welcome.