Fix cursor display at EOL before extended face

* src/xdisp.c (extend_face_to_end_of_line): Make sure the
character position of the stretch glyph inserted to extend the
face is zero, as various other parts of the display code rely
on that.  (Bug#38330)
1 job for master in 60 minutes and 53 seconds (queued for 3 seconds)
Status Job ID Name Coverage
failed #4328


Name Stage Failure
test-all Test
Makefile:319: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:294: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:959: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1