Bugs item #824, was opened at 2007-06-25 23:22 You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=493&aid=824&group_id=106 Category: Image inclusion Group: v1.40.3 Status: Open Resolution: Accepted Priority: 5 Submitted By: Robin Houston (robinhouston) Assigned to: Martin Schröder (oneiros) Summary: Bus error caused by loading an image into a format file Initial Comment: I have written a tool that speeds up repeated compilation of a source file, by generating a format from the preamble of the document, and then using it to compile the body. One user reported a crash when using this tool with a custom letterhead class; the class in question may be found at http://www.soe.ucsc.edu/~elm/LaTeX/ucletter.cls (though note that a simpler demonstration is attached to this report). The bug is triggered by the fact that this class loads an image during the processing of the preamble (i.e. during the processing of the .ini file) and saves it in a box. When this box is used, during the compilation of the body, pdftex crashes. This does work with ordinary (non-PDF) TeX, so the problem is specific to PDFTeX. The attachment contains a simple demonstration of the problem. Unpack it and run 'make'. ----------------------------------------------------------------------

Comment By: Robin Houston (robinhouston) Date: 2007-06-30 17:56

Message: Logged In: YES user_id=4579 The attached patch (initex-objects.patch) implements the suggestions made below, together with a few other improvements. It incorporates Taco Hoekwater's code, so should be applied to a clean source tree. In particular, it reinstates the ability to produce both a PDF document and a memory dump in the same run. I've tested it with \pdfxform as well as \pdfximage. Comments? Counterexamples? Robin ---------------------------------------------------------------------- Comment By: Robin Houston (robinhouston) Date: 2007-06-30 13:38 Message: Logged In: YES user_id=4579 Fortunately the "two picture" problem (demonstrated in the attachment twopic.tar.gz) is trivial to solve: simply dump and undump the variable pdf_ximage_count. Presumably the same should be done for pdf_obj_count and pdf_xform_count. Whether this is sufficient, I have no idea: none of us have tested forms or raw objects, have we? ---------------------------------------------------------------------- Comment By: Robin Houston (robinhouston) Date: 2007-06-30 11:08 Message: Logged In: YES user_id=4579 A minor bug in the initex-refximage-dump.patch: the test for fixed_pdfoutput=1 ought to be fixed_pdfoutput>0, otherwise it will fail with \pdfoutput=2, say. Another unrelated problem is that, if you load an image from the .ini file, and then load and display another image from the .tex file, the first image will appear where the second one ought to be. I'll try and find out why this is happening. (Incidentally, I haven't (yet?) discovered any problems stemming from not (un)dumping the linked list headers.) ---------------------------------------------------------------------- Comment By: Robin Houston (robinhouston) Date: 2007-06-29 19:08 Message: Logged In: YES user_id=4579 Argh! Interesting, thanks. Clearly my understanding of the pdftex code is patchy at best. That said, what is gained by dumping and restoring the head_tab? If I remove the parts of your code that dump and undump the head_tab, then your example works (and mine continue to work). Robin ---------------------------------------------------------------------- Comment By: Taco Hoekwater (taco) Date: 2007-06-29 17:32 Message: Logged In: YES user_id=1608 Try a document that contains items besides a single image. Many of the auxiliary tables are not dumped, resulting in assertion failures in the non-ini run. You don't even need to save or reuse boxes for those crashes, just make a pair of: % test.ini \input plain \pdfoutput=1 hello \dump % test.tex world! \end ---------------------------------------------------------------------- Comment By: Robin Houston (robinhouston) Date: 2007-06-29 16:24 Message: Logged In: YES user_id=4579 PS. I have just attached a new tar file, containing some simple tests that create PDF from the IniTeX run. They all appear to work, when my patch is applied. ---------------------------------------------------------------------- Comment By: Robin Houston (robinhouston) Date: 2007-06-29 16:19 Message: Logged In: YES user_id=4579 I don't think creating a PDF file from the IniTeX run is a real problem. The attached tiny patch (to be applied on top of Taco Hoekwater's first patch) seems to make it work. Am I missing something? ---------------------------------------------------------------------- Comment By: Taco Hoekwater (taco) Date: 2007-06-29 11:34 Message: Logged In: YES user_id=1608 Here is the promised extra patch. No error is generated, just a simple warning. Pdftex continues executing as if \end was given instead. ---------------------------------------------------------------------- Comment By: Nobody (None) Date: 2007-06-28 21:33 Message: Logged In: NO Hi, the inability to _both_ dump a format _and_ produce output in the same iniTeX run is probably tolerable as long as no crashes occur. I don't know the workings of WhizzyTeX in detail: it is conceivable that their in-document dump would be affected. However, it is unlikely that WhizzyTeX will indeed require both the output as well as the dump (the dump may well contain pictures, for example from floats that are going to be placed later), so there is at least a reasonable way to tackle this from the macro level (divert \shipout in the manner of the everyshi.sty package). At least mylatex.ltx (and consequently preview-latex) should work fine: \shipout before \begin{document} would be extremely unusual and would result in strange results, anyway. David ---------------------------------------------------------------------- Comment By: Taco Hoekwater (taco) Date: 2007-06-28 20:09 Message: Logged In: YES user_id=1608 Small limitation that I have yet to implement: the ability to move stuff over from the initex run means that if initex actually creates a pdf file, dumping a format should be disallowed, or silently ignored. Attempting to keep track of two disjunct pdf documents is just too hard for me. Note that I do not want to prohibit pdf creation from initex. Just that you can't create a pdf document _as well as_ perform a \dump. ---------------------------------------------------------------------- Comment By: Robin Houston (robinhouston) Date: 2007-06-28 16:01 Message: Logged In: YES user_id=4579 Bravo! I was ready to embark on this myself, so I'm delighted to be spared the trouble. It passes all the tests I've tried so far. ---------------------------------------------------------------------- Comment By: Taco Hoekwater (taco) Date: 2007-06-28 11:57 Message: Logged In: YES user_id=1608 Here is a patch that fixes the problem by dumping and restoring the image _meta information_ to/from any generated format. The image _data_ is not included (that would be really hard to do in a portable way), and therefore the undumping routines have to redo most of the work of \pdfximage, but this is transparent to the user except that the tests for \pdfminorversion and \pdfinclusionerrorlevel tests are re-done. The patch also saves some pdftex arrays that are needed to rediscover the object. This could eventually be extended to make sure \refxform et al work as well. As of now, that is untested due to lack of example. Comments and testing welcome, as always. ---------------------------------------------------------------------- Comment By: Martin Schröder (oneiros) Date: 2007-06-26 22:01 Message: Logged In: YES user_id=421 Sorry, pdf things work different then dvi, so we can not make \pdfximage etc. in ini mode without a lot of work; we will probably disable a bunch of primitives. ---------------------------------------------------------------------- Comment By: Robin Houston (robinhouston) Date: 2007-06-26 14:49 Message: Logged In: YES user_id=4579 Simplifying the example by eliminating the graphics package: ==> foo.ini <== \documentclass{minimal} \newbox\picbox \pdfximage{pic.pdf} \setbox\picbox\hbox{\pdfrefximage\pdflastximage} \dump ==> foo.tex <== \begin{document} \box\picbox \end{document} Also, I see now that my comparison with dvi-mode is indeed a false one, because the mechanisms are quite different, and the DVI graphics driver only has to include a \special, rather than the graphic itself. A simple solution, I suppose, would be to make \pdfrefximage (and, presumably, the other \pdfrefx commands) invalid in IniTeX mode. Perhaps this is too brutal, since it forbids certain harmless activities such as finding the dimensions of an image from an .ini file; and of course I would be delighted if it were made to work instead. ---------------------------------------------------------------------- Comment By: Reinhard Kotucha (reinhard) Date: 2007-06-26 00:26 Message: Logged In: YES user_id=4195 Martin, you probably can't do everything in a format file. However, it would be nice to be able to put graphics to a format file at least. Suppose that a web server has to generate PDF files on-the-fly, each contains a company logo. The best place place for the logo is the format file if speed matters. It would be nice if there are no restrictions. Regards, Reinhard ---------------------------------------------------------------------- Comment By: Robin Houston (robinhouston) Date: 2007-06-25 23:42 Message: Logged In: YES user_id=4579 I'm impressed by the speed of your response! Thanks. If you replace the PDF image by an EPS file, and use -output-format dvi, then it does work. That suggests to me that the problem is not fundamentally caused by a limitation of IniTeX. But I don't know enough about the inner workings of the \includegraphics command to be sure about that. (Perhaps PDF graphics are handled in a sufficiently different way for this to be a false comparison?) In any case, as you say, it shouldn't crash! ---------------------------------------------------------------------- Comment By: Martin Schröder (oneiros) Date: 2007-06-25 23:30 Message: Logged In: YES user_id=421 I can reproduce it, and it obviously shouldn't crash, but I'm really not shure if it's supposed to work, as the format of course will not save the picture. You can't do everything in IniTeX... ---------------------------------------------------------------------- You can respond by visiting: http://sarovar.org/tracker/?func=detail&atid=493&aid=824&group_id=106