Chronological Thread 

< Chronological >      < Thread >

---

I just isolated a very annoying typesetter bug which kept screwing up a
document I am working on. Now, I would have posted it to the TeXmacs
Resources WikiWeb, but the antalia server seems to be down at the moment (I
get a 502, Proxy Error).

I attached all the documents I talk of here in one archive.

The bug
-------

To reproduce the bug you need to have a document with at least three floats.
I used floats appended at the end of each paragraph. In floatup1.tm, I have
put enough text in each paragraph so that each float is placed at its 'here'
location. If the amount of text in a paragraph is too small, the floats may
be grouped togheter. For the first example I want each float to be separated
from the other.

All the floats after the second one are forced on the top of the page, even
if they are allowed to be placed anywhere except at 'top'.

Moreover, such floated-up floats, if they are *not* the last float in the
flow, will cause the space under the line they are placed at (in the document
tree, not on the typeset boxes) to be reduced to zero. If you remove the
'Finally some table', it causes the vertical space after the 'Some text
again' paragraph to reappear.

A workaround
------------

I must admit that having floats stuck at the top of the page is annoying but
not fatal. But having vertical space removed is NOT acceptable. Luckily, you
can work around it by forbidding placement at 'here' for floated-up floats.

More info
---------

The floatup2.tm and floatup3.tm documents display interesting behaviour which
could help track down the origin of the problem.

It looks like the bug is triggered by some side effect taking place at the
moment the second float is flushed.

The floatup2.tm document shows this pretty clearly. As given, the first and
second floats are flushed because of the presence of the third float. As a
proof, try to remove the third float, and the first two floats will be
flushed one paragraph farther (because the 'some table again' will be a third
float, and cause the flush).

Any float after the second one will get stuck at the top of the page, even if
it was flushed at the same time. That is also visible in the floatup2.tm
document.

The floatup3.tm document uses multicolum to show how this problem may
interact with the page breaker. Here, 'professional' page breaking is used.

Personal Conlusion
------------------

Is there anyone here, besides Joris, who understands how TeXmacs' typesetter
works? I'm getting tired of typing typesetter bug reports, they are almost
always hard to isolate, and long to describe. I think the typesetter code
would definitely gain from being more widely eyeball-proofed.

Attachment: floatup.tar.bz2
Description: BZip2 compressed data

---

• Bug report: Floats floating up, David Allouche, 01/03/2002
  • Re: Bug report: Floats floating up, Álvaro Tejero Cantero, 01/03/2002

---

Archive powered by MHonArc 2.6.19.