Error writing metadata after copying all from another image

@Rob: what does the destination file contains in the first place? Is it an empty or non existing file? Another image file that already contains metadata? If so, can you please attach it here as well?

What is the "other bug" the try... except block in your sample code is working around?

Sorry should have commented it better , the try... except block in my sample code is to work around Bug #256875 (Unable to add/modify multiple value short tags)

And what about the destination file (see my previous question)?

After further testing it occurs with a destination file that is a valid JPEG both with or without existing metadata.

If the destination not a valid JPEG or does not exist the appropriate errors for those conditions are raised as expected.

script below, this image: http://www.flickr.com/photos/damienmoore/4012190227/

output:
Problems copying Exif.Pentax.Flash keyword
Traceback (most recent call last):
  File "/home/damien/Desktop/exiv2test.py", line 20, in <module>
    dest.writeMetadata()
ValueError: Unsupported data area offset type

-------------------------------------------------------------------
import pyexiv2
import Image
im=Image.open("imgp1115.jpg")
im.save("imgp1115_copy.jpg")

src=pyexiv2.Image("imgp1115.jpg")
src.readMetadata()

dest=pyexiv2.Image("imgp1115_copy.jpg")
dest.readMetadata()

l=src.exifKeys() + src.iptcKeys()

for i in l:
        try: # work around for another bug
            dest[i] =src[i]
        except:
            print "Problems copying %s keyword" %i

dest.writeMetadata()

I forgot to add: Running Ubuntu Jaunty with whatever is the default version of pyexiv2. I've noticed that the writeMetadata call does work if I ony write a subset of the metadata (the stuff used by phraymd -- a mix of the most useful IPTC and Exif tags) so it's clearly just some keys causing a problem.

Ubuntu Jaunty ships with pyexiv2 0.1.3.

Note that the test script can be simplified (the source image from flickr only contains EXIF metadata).

I did some tests with the following script:

import pyexiv2
src = pyexiv2.ImageMetadata('4012190227_e31307c04a_o.jpg')
src.read()
dst = pyexiv2.ImageMetadata('4012190227_e31307c04a_o-copy.jpg')
dst.read()
for key in src.exif_keys:
    dst[key] = src[key]
dst.write()

Two issues arise:
1) The 'Exif.Pentax.Temperature' tag is of type SByte, currently not supported (but trivial to implement).
2) Copying the metadata works and writing back the file as well, but after comparing the output of `exiv2 -p a` on the source file and on the destination one there are quite a few discrepancies. That requires more investigation.