Old source files without license header?


Two weeks ago I tried to contact a former developer of KTimeTracker
[1] to license two files under GPL. I got no response from him since
then, but may be we can assume the license is still GPLv2...

The reasons why it might be OK to just add a GPLv2 license header
without asking:
1. When these "unlicensed" files were committed into KDE SVN
repository in 2009, the root directory for KTimeTracker sources also
contained a COPYING file with GPLv2 terms. This could imply that
anything committed under the directory is automatically licensed under
2. According to GPLv2+, it's illegal to modify a GPLv2+ project and
not license it under GPLv2 or later version. Thus, assuming the author
didn't intend to break the license, we may consider two cases:
- he intended to license the modified version as GPLv2 (but forgot
to add the headers into the files),
- he intended to relicense the modified version as GPLv3. However
the other files are still under GPLv2, thus this case can't be right.

IANAL, so what do you think - is it OK to just add GPLv2 license
headers to files that never had them?

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