bugGNU TeXmacs - Bugs: bug #37638, PostScript import issue

 
 

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bug #37638: PostScript import issue

Submitted by:  Albert Graef <agraef>
Submitted on:  Sat 27 Oct 2012 10:38:14 AM UTC  
 
Category: ConversionPriority: 5 - Normal
Item Group: ErrorStatus: In Progress
Privacy: PublicAssigned to: Massimiliano Gubinelli <mgubi>
Originator Name: Open/Closed: Open
Release: r5795Release: None
Fixed Release: NoneFixed Release: 
Keywords: 

Wed 31 Oct 2012 08:53:41 AM UTC, comment #5:

After investigating some more, I think that the floating point exception message actually comes from ghostscript, not texmacs. I get exactly the same message with the pstopnm program:

$ pstopnm psbug.ps
Floating point exception

So this might just be an issue with postscript import after all. Unfortunately, poor Gimp doesn't let me create a 0x0 png image, so I can't test whether that might cause issues as well. ;-)

Albert Graef <agraef>
Wed 31 Oct 2012 08:39:38 AM UTC, comment #4:

I should mention that the suggested patch (file #26861) only fixes the problem for postscript import, of course. It is quite possible that the same kind of havoc might still happen with other image types if the image has zero height, I haven't tested that yet.

Apparently texmacs tries to calculate h_wd/h_pt somewhere (sloppy coding?), which gives the floating point exception. As this would normally yield a nan floating point value with IEEE754 floats in C/C++, maybe the issue is actually in Scheme/Guile code? Anyway, as I said, the root cause is most likely somewhere else.

Albert Graef <agraef>
Wed 31 Oct 2012 08:28:40 AM UTC, comment #3:

Fixed a minor glitch in the suggested patch, attached.

(file #26861)

Albert Graef <agraef>
Wed 31 Oct 2012 08:24:52 AM UTC, comment #2:

The attached minimal postscript file with an empty bounding box reproduces the problem (as verified this morning using the latest from trunk).

I think that just setting h_pt to 1 should always be ok, since the picture is then still empty and will correctly be displayed as such in texmacs once this second part of the issue is fixed.

Actually, you need to do that change in two places (at least), as indicated by the attached patch against the latest revision.

(file #26859, file #26860)

Albert Graef <agraef>
Sun 28 Oct 2012 02:37:25 PM UTC, comment #1:

I committed the patch (r5796) but I didn't commited the modification to avoid image height = 0. Could you provide me a way to trigger the Floating point exception so that I can fix this in the right way? I cannot reproduce this part of the problem.

Massimiliano Gubinelli <mgubi>
Project AdministratorIn charge of this item.
Sat 27 Oct 2012 10:38:14 AM UTC, original submission:

When trying to insert a PostScript image, I get the following message, then texmacs exists with an exit code of 136:

TeXmacs Cannot read image file '/home/ag/Desktop/texmacs-test/golfer.eps' in gs_image_size
Floating point exception

This can be reproduced with all but two of the sample PostScript files from the ghostscript package. It's a glaring bug in the gs_image_size_sub() routine in gs_utilities.cpp. Because of the bug, the bounding box isn't found, image width and height get both set to zero which then subsequently causes the floating point exception (maybe division by zero?). The attached patch fixes both issues.

(I'm running this on Linux, Ubuntu 11.04, x86_64.)

Can anyone please commit the patch? Note: The zero division issue probably requires further investigation, the patch only works around this by setting the default h_pt value to 1 instead of 0.

Thanks,
Albert

Albert Graef <agraef>

 

Attached Files
file #26861:  psbug.patch added by agraef (679B - text/x-patch)
file #26859:  psbug.ps added by agraef (43B - application/postscript)
file #26860:  psbug.patch added by agraef (668B - text/x-patch)
file #26834:  postscript-import.patch added by agraef (913B - text/x-patch)

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -unavailable- added by mgubi (Posted a comment)
  • -unavailable- added by agraef (Submitted the item)
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    Follow 7 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Wed 31 Oct 2012 08:28:40 AM UTCagraefAttached File-=>Added psbug.patch, #26861
    Wed 31 Oct 2012 08:24:52 AM UTCagraefAttached File-=>Added psbug.ps, #26859
      Attached File-=>Added psbug.patch, #26860
    Sun 28 Oct 2012 02:38:56 PM UTCmgubiStatusNone=>In Progress
      Assigned toNone=>mgubi
      Releasecurrent svn=>r5795
    Sat 27 Oct 2012 10:38:14 AM UTCagraefAttached File-=>Added postscript-import.patch, #26834

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