Failing to parse a raw value silently fails

[Olivier Tilloy]

Version of pyexiv2: bzr head (lp:pyexiv2 as of 2010-09-21, revision 325).
Version on libexiv2: 0.20.0

Script to reproduce the issue:

import pyexiv2
fn = 'test/data/smiley1.jpg'
m = pyexiv2.ImageMetadata(fn)
m.read()
value = '2 0 0 0 '
m['Exif.GPSInfo.GPSVersionID'] = value
m.write()
del m
m = pyexiv2.ImageMetadata(fn)
m.read()
assert(m['Exif.GPSInfo.GPSVersionID'].value == value)

Expected result: no-op.
Current result: an AssertionError is raised.

[Olivier Tilloy (osomon)]

Note: the behaviour seems to be different if the tag is already present in the image. If not present yet, it will be written with an empty value as shown in the script above. If already present, its value is simply not overwritten.

[Olivier Tilloy (osomon)]

Running Ubuntu 10.10 beta, that ships with libexiv2 0.19, I can’t reproduce the issue. I’ll test with 0.20.

[Olivier Tilloy (osomon)]

I can reproduce the issue with libexiv2 0.20 compiled from source.
0.19 (package in ubuntu and compiled from source) works fine, 0.20 doesn’t.

[Olivier Tilloy (osomon)]

The issue seems to be with the trailing white space in the value. When setting the value of 'Exif.GPSInfo.GPSVersionID' to '2 0 0 0', this works as expected (with libexiv2 0.20).
It is easy enough to suppress trailing spaces on the fly and to make sure that pyexiv2.utils.string_to_undefined(...) returns strings with no trailing spaces. I will add corresponding unit tests.

[Olivier Tilloy (osomon)]

Additionally, the code should check the return value of Exiv2::Metadatum::setValue(const std::string &) and throw an exception if ≠ 0.

[Olivier Tilloy (osomon)]

Fix committed to trunk at revision 328.