[9fans] page and plumbing

[9fans] page and plumbing

[Martin Neubauer]

Hello,

After a pull two days ago I noticed that plumbing images to page does not
work any more. Page still starts but exits immediately before displaying
anything. Starting page manually works as expected. As postscript and pdf
files as well as other plumbing targets are unaffected led me to to suspect
the new image handling code somehow interfers with plumbing.

If nobody has a fix ready or some deeper insights, I might have some spare
time to look into this a little further during the weekend.

	Martin

Re: [9fans] page and plumbing

[Russ Cox]

> After a pull two days ago I noticed that plumbing images to page does not
> work any more. Page still starts but exits immediately before displaying
> anything. Starting page manually works as expected. As postscript and pdf
> files as well as other plumbing targets are unaffected led me to to suspect
> the new image handling code somehow interfers with plumbing.

True enough.  Here is a better solution:

cpu% diff -c /n/sources/plan9//sys/src/cmd/page/cache.c /sys/src/cmd/page/cache.c
/n/sources/plan9//sys/src/cmd/page/cache.c:151,156 - /sys/src/cmd/page/cache.c:151,159
  	Image *im;
  	int ra;

+ 	if(doc->npage < 1)
+ 		return display->white;
+
  	im = _cachedpage(doc, angle, page, "");
  	if(im == nil)
  		return nil;
cpu%

Sorry about that -- I'd forgotten about -i,
which has always been a hack.

I've submitted this as a patch.

It is unfortunately not related to
Greg Pavelcak's problems, which
I have not been able to reproduce.
The new page works fine for me in
drawterm.  That sounds like drawterm
is running out of image memory
somehow, but I don't see how, and
even if it did it should be behaving
more gracefully.

Russ