msbuild task fails when no AssemblyInfo file is present

[PatrickKursawe]

I think this was introduced with 6caae2e
The AssemblyInfoBuilder picks the correct implementation based on the file suffix for AssemblyInfo, but if no such file is present, it tries to access the dictionary with a null key, resulting in an ArgumentNullException.

[asbjornu]

@PatrickKursawe I fixed a lot of things related to AssemblyInfo patching in #882. It's merged, but not released yet. Do you think it might remedy the problem you're seeing? If not, do you think you can create a test that illustrates the problem?

[PatrickKursawe]

Does not look like the faulty part was touched. A test project within its own repository is attached.
VersionTaskBug.zip

[tpluscode]

No biggie, but i still occurs in version 3.5.4.

FYI it also occurs when the assembly info file is not set to BuildAction = Compile

[asbjornu]

@tpluscode Yea, #882 isn't released yet.

@PatrickKursawe I'll hopefully have time to look at that test project some time this week.