Comment 83 for bug 40058

I've been digging through the code a bit. The method get_changelog does the following:

1. Get the version of the binary package.
2. Get the version of the source package.
3. Compare both versions.
4. Use the highest version to get the changelog file.

Applying this to cpp package:
- Binary version = 4:4.2.3-1ubuntu6
- Source package = gcc-defaults
- Source version (first encountered) = 1.62ubuntu3
- Resulting location = gcc-defaults/gcc-defaults_4.2.3-1ubuntu6/changelog
- Actual location = gcc-defaults/gcc-defaults_1.62ubuntu3/changelog

So the version comparison either needs to be removed or refined. I'll leave it to the package maintainer to work that out.