[PATCH 0/4] Add more tests of cvsimport

The test suite for "git cvsimport" is pretty limited, and I would like to improve the situation. This patch series contains the first of what I hope will eventually be several additions to the "git cvsimport" test suite.

I am the maintainer of cvs2svn/cvs2git. Most of the new tests will probably use fragments from the cvs2svn test suite. I should admit that part of my motivation for adding tests to the "git cvsimport" test suite is to document its weaknesses, which do not seem to be especially well known.

Patch 1 splits out some code into a library usable by multiple CVS-related tests.

Patch 2 changes the library to add the -f option when invoking cvs (to make it ignore the user's ~/.cvsrc file).

Patch 3 adds a new test to t9600, namely to compare the entire module as checked out by CVS vs. git.

Patch 4 adds a new test script t9601 that tests "git cvsimport"'s handling of CVS vendor branches. One of these tests fails due to an actual bug.

These ideas in the patches are logically independent of each other, but each patch assumes that the previous patches have been applied.

I would like to point out a few things about these patches that seem a little bit unprecedented in the git test suite. If other approaches would be preferred, please let me know.

The first is that I would like to introduce a library that can be used by the "git cvsimport" tests in the t96xx series, simply to avoid code duplication. I put this library in t/t96xx/cvs-lib.sh, to hopefully make its role clear. The library has to be sourced from the main test directory. (It sources test-lib.sh indirectly.)

The second is that the new test script uses a small CVS repository that is part of the test suite (i.e., the *,v files are committed directly into the git source tree). This is different than the approach of t9600, which creates its own test CVS repository using CVS commands. The reasons for this are:

- t9600 wants to test incremental import, so it *has to* create the
  repository dynamically.  That is not the case for t9601, which only
  tests a one-shot import.

- The repository for t9601 is derived from one that already exists as
  part of the cvs2svn test suite.  Reverse-engineering it into CVS
  commands would be extra work.

- The code to create CVS repositories via CVS commands is not very
  illuminating, and runs slowly, as CVS throttles commits to 1 per
  second (to ensure unique timestamps).

- Future tests may require even more complicated CVS repositories that
  are even more cumbersome to create, so it's good to set a precedent
  now :-)

Finally, the *,v files comprising the CVS repository have blank trailing lines, triggering a warning from "git diff --check". I don't think that CVS strictly requires the blank lines, but they are always generated by CVS, so I left them in. But if the "git diff --check" warnings are considered a serious problem, the blank lines could probably be removed.

Cheers, Michael