[tex4ht] [bug #345] regression testing is needed

[Karl Berry]

    build.lua is a driver file with settings for the main l3build.lua script.

I know.  My question was whether l3build.lua is a fork (modified by you)
or a copy of the original l3build.lua file from the l3build
package. Which you answered below -- you made changes. Ok.

    Probably it would be better to give  it a different name, 

build.lua -> l3test4ht.lua comes to mind.

As for l3build.lua, it would be much better not to have it committed in
our repository at all, but to use their installed version. We don't want
to continually be merging new versions, and sticking with an old version
"forever" doesn't sound good either.

    just simple fix in l3build.lua:
       os_diffexe  = os.getenv("diffexe") or "diff -c --strip-trailing-cr --ignore-matching-lines='<meta name=\"date\"'"

The problem is that is not a change they can accept upstream, since it
is tex4ht- (and HTML-) specific.

I'm not sure if they already have a way to allow for such customization
by a user of l3build (us). We could ask for advice.

Another possibility that comes to mind is to change tex4ht to avoid
generating the date line in the first place, or remove it in the
Makefile before running l3build.

Thanks,
Karl