bug#13718: [patch] prevents hl-line from overriding highlight-mode

[Stefan Monnier <monnier@iro.umontreal.ca>]

> I found that the overlays in highlight-mode do not override the
> overlays from global-hl-line-mode, causing them to disappear on the
> currently active line.

hl-line seems to leave its overlay's priority unspecified (good!), which
means that it should take precedence over overlays which are larger
(e.g. span multiple lines) while smaller overlays within the current
line should take precedence over it.

Can you describe your particular case?  What are the overlays that
"disappear", what do they cover, and why do you think they should not
"disappear" like that?

> The solution I found was to edit hi-lock.el to
> increase the priority of the overlay, as outlined in this patch:

I must admit to disliking explicit overlay priorities, which tend to
just lead to more problems down the road (needing to specify priorities
on more overlays, which in turn cause yet more problems, ...), so if at
all possible, I'd rather avoid doing that.


        Stefan