IssueTracker

Component used: androidx.exifinterface

Version used: 1.3.2+

Devices/Android versions reproduced on: Pixel 2 API 23 (it is just an example it might take place on other devices too)

Hi I'm Grzegorz from ODK Collect (https://github.com/getodk/collect). In our app we support scaling down images to make them smaller. We want them to keep their exif data so we copy it first before the operation and add to a newly created image: https://github.com/getodk/collect/blob/master/collect_app/src/main/java/org/odk/collect/android/utilities/ImageConverter.kt#L48

We have noticed that in cases an exception is thrown when we try to save attributes.

     Caused by: java.lang.NullPointerException: Attempt to get length of null array
        at java.io.OutputStream.write(OutputStream.java:82)
        at androidx.exifinterface.media.ExifInterface$ByteOrderedDataOutputStream.write(ExifInterface.java:7958)
        at androidx.exifinterface.media.ExifInterface.writeExifSegment(ExifInterface.java:7585)
        at androidx.exifinterface.media.ExifInterface.saveJpegAttributes(ExifInterface.java:6321)
        at androidx.exifinterface.media.ExifInterface.saveAttributes(ExifInterface.java:4759)
        at org.odk.collect.android.utilities.ImageConverter.execute(ImageConverter.kt:47) 

In our codebase we catch that exception but it corrupts the new image and we can't use it.

From my investigation I know that the exception takes place if:

• exif contains a thumbnail
• and our new image is much smaller than the original one (here it is difficult to tell what size the image should have I was able to reproduce the issue scaling down images taken by default camera app to sizes where the longer edge was 100px but our users have reported issues with even bigger values like 640px)

Here is the issue in our repository: https://github.com/getodk/collect/issues/5033