2005.10.15 16:06 "[Tiff] Re: Small bug report, and error handler parameter issue", by Frank Warmerdam

On 10/15/05, Joris <joris.at.lebbeke@skynet.be> wrote:

1) In LibTiff 3.7.4, tif_write.c, line 520:

 if (tif->tif_dir.td_samplesperpixel == 1) {
  /*

   * Planarconfiguration is irrelevant in case of single band
   * images and need not be included. We will set it anyway,
   * because this field is used in other parts of library even
   * in the single band case.
   */

  tif->tif_dir.td_planarconfig == PLANARCONFIG_CONTIG;
 } else {

...This last '==' should, I think, be '='.

Joris,

I have applied this change.

2) The issue of the parameters of the warning and error handlers has come up before. I totally fail to do anything meaningfull with warning and errors in a context that envolves multiple TIFF * in a single thread, because there is no TIFF * parameter in the warning and error handler callbacks, and thus the warnings and errors can't be traced to their TIFF context and dealt with properly.

I now find myself in a situation where I really need that. So I've extended the error handler with that TIFF * parameter, and changed all TIFFError and TIFFWarning calls in the core library accordingly. I haven't updated any of the tools, I don't know if it will seriously impact those. Is there any chance this could find its way into CVS, so that I don't have to change again with each new update? I'm pretty sure people are all for the ability to present error more meaningfull then 'The TIFF file can not be opened because there was an error opening the TIFF file', even when multiple TIFFs are involved. I can't build a diff, but I can send the complete edited sources for you more tools-enabled Linux guys to diff.

This change would break many existing applications that use libtiff (as I understand the change), and thus I don't think it could be contemplated except as part of a major generational step, presumably to libtiff 4.0.

So, my position is that it should not be done till we are needing to do alot of other disruption. These sort of API changes in a stable and established library like libtiff cause alot of waves.

Best regards,
--

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