Fri, 10 Apr 2026 15:00:30 +0000 https://bugs.horde.org/ticket/8761 Divide by zero error in /ansel/lib/Exif.php There appears to be a bug in Exif.php where it doesn't check to see whether it's about to divide by zero when calculating the shutter speed. This patch fixes the issue in /ansel/lib/Exif.php. Tue, 08 Dec 2009 22:42:07 +0000 https://bugs.horde.org/ticket/8761#t57064 Looks like there are lots of places in Exifer's original code that this should be checked...OTOH, the exif standard says that values for those fields shouldn't contain a zero denominator and are rational numbers. What is the source of the exif information that is broken? Can you upload a sample image file? Also, please read docs/CODING_STANDARDS when submitting future patches, and thanks! Wed, 09 Dec 2009 01:32:11 +0000 https://bugs.horde.org/ticket/8761#t57075 > Looks like there are lots of places in Exifer's original code that > this should be checked...OTOH, the exif standard says that values for > those fields shouldn't contain a zero denominator and are rational > numbers. What is the source of the exif information that is broken? > Can you upload a sample image file? I'm on my phone right now which has uploads disabled. The file is at http://jon.spriggs.org.uk/exif_error.jpg > Also, please read docs/CODING_STANDARDS when submitting future > patches, and thanks! Will do. Jon Wed, 09 Dec 2009 10:44:00 +0000 https://bugs.horde.org/ticket/8761#t57078 Changes have been made in CVS for this ticket: Protect from divide-by-zero errors due to faulty exif data. Bug: 8761 Submitted by: jon (at) spriggs (dot) org (dot) uk http://cvs.horde.org/diff.php/ansel/lib/Exif.php?rt=horde&r1=1.41.2.11&r2=1.41.2.12&ty=u Sun, 13 Dec 2009 23:38:31 +0000 https://bugs.horde.org/ticket/8761#t57137 Changes have been made in Git for this ticket: Protect against division by zero from faulty exif data. Bug: 8761 http://git.horde.org/diff.php/framework/Image/lib/Horde/Image/Exif.php?rt=horde-hatchery&r1=6b4e0ea33bc6cfa1269e6dca4f56f89f421921c0&r2=e2c90271b152af30c18674bef5e93e742b90097e Sun, 13 Dec 2009 23:42:45 +0000 https://bugs.horde.org/ticket/8761#t57138 Seems like the php native exif functions return invalid data for some fields when the value is not defined in the image source. Fixed, though instead of returning zero like your patch did, we simply return from the function, since the value of x/0 is not 0, but undefined. Thanks for the catch! Sun, 13 Dec 2009 23:45:03 +0000 https://bugs.horde.org/ticket/8761#t57139 Changes have been made in Git for this ticket: Protect against division by zero from faulty exif data. Bug: 8761 http://git.horde.org/diff.php/framework/Image/lib/Horde/Image/Exif.php?rt=horde-git&r1=6b4e0ea33bc6cfa1269e6dca4f56f89f421921c0&r2=e2c90271b152af30c18674bef5e93e742b90097e Wed, 13 Jan 2010 00:17:46 +0000 https://bugs.horde.org/ticket/8761#t57677