[PATCH v2 0/5] Some fixes and an improvement for using CTest on Windows

Visual Studio users enjoy support for running the test suite via CTest, thanks to Git's CMake definition.

In https://github.com/git-for-windows/git/issues/3966, it has been reported that this does not work out of the box, though, but causes a couple of test failures instead. These problems are not caught by Git's CI runs because the vs-tests jobs actually use prove to run the test suite, not CTest.

In addition to fixing these problems, this patch series also addresses a
long-standing gripe I have with the way Git's CMake definition supports
CTest: It edits t/test-lib.sh, which leaves this file eternally modified
(but these modification should never be committed, they refer to a
local-only, configuration-dependent directory).

Note: The signed/unsigned comparison bug in git add -p that is fixed in this
here patch series is a relatively big one, and it merits further
investigation whether there are similar bugs lurking in Git's code base.
However, this is a much bigger project than can be addressed as part of this
patch series, in particular because the analysis would require tools other
than GCC's -Wsign-compare option (which totally misses the instance that is
fixed in this here patch series).

Changes since v1:

 * Clarified why it is a good idea to pass --no-bin-wrappers and
   --no-chain-lint when running on Windows.
 * Clarified why the add -p bug has not been caught earlier.
 * Clarified the scope of this patch series to fix running Git's tests
   within Visual Studio.
 * Increased the time-out for the very slow t7112 test script.
 * The test_chmod was determined to be not only faulty, but unneeded, and
   was dropped.

Johannes Schindelin (5):
  cmake: make it easier to diagnose regressions in CTest runs
  cmake: copy the merge tools for testing
  add -p: avoid ambiguous signed/unsigned comparison
  cmake: avoid editing t/test-lib.sh
  cmake: increase time-out for a long-running test

 .gitignore                          |  1 +
 Makefile                            |  1 +
 add-patch.c                         |  2 +-
 contrib/buildsystems/CMakeLists.txt | 16 ++++++++--------
 t/test-lib.sh                       | 11 ++++++++++-
 5 files changed, 21 insertions(+), 10 deletions(-)

base-commit: bbea4dcf42b28eb7ce64a6306cdde875ae5d09ca
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1320%2Fdscho%2Fctest-on-windows-v2
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1320/dscho/ctest-on-windows-v2
Pull-Request: https://github.com/gitgitgadget/git/pull/1320

Range-diff vs v1:

 1:  9cf14984c0a ! 1:  e00cb37b98a cmake: align CTest definition with Git's CI runs
     @@ Metadata
      Author: Johannes Schindelin <Johannes.Schindelin@gmx.de>
      
       ## Commit message ##
     -    cmake: align CTest definition with Git's CI runs
     +    cmake: make it easier to diagnose regressions in CTest runs
      
     -    In Git's CI runs, the Windows tests are run with `--no-bin-wrappers` and
     -    `--no-chain-lint`, mainly to win back some time caused by the serious
     -    performance penalty paid for the tests relying so heavily on POSIX shell
     -    scripting, which only works by using a POSIX emulation layer.
     +    When a test script fails in Git's test suite, the usual course of action
     +    is to re-run it using options to increase the verbosity of the output,
     +    e.g. `-v` and `-x`.
      
     -    Let's do the same when running the tests, say, in Visual Studio.
     +    Like in Git's CI runs, when running the tests in Visual Studio via the
     +    CTest route, it is cumbersome or at least requires a very unintuitive
     +    approach to pass options to the test scripts.
      
     -    While at it, enable the command trace via `-x` and verbose output via
     -    `-v`, otherwise it would be near impossible to diagnose any problems.
     +    So let's just pass those options by default: This will not clutter any
     +    output window but the log that is written to a log file will have
     +    information necessary to figure out test failures.
     +
     +    While at it, also imitate what the Windows jobs in Git's CI runs do to
     +    accelerate running the test scripts: pass the `--no-bin-wrappers` and
     +    `--no-chain-lint` options. This makes the test runs noticeably faster
     +    because the `bin-wrappers/` scripts as well as the `chain-lint` code
     +    make heavy use of POSIX shell scripting, which is really, really slow on
     +    Windows due to the need to emulate POSIX behavior via the MSYS2 runtime.
      
          Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
      
 2:  86ab58b6508 = 2:  de7b47a9aa7 cmake: copy the merge tools for testing
 3:  79abfa82c32 < -:  ----------- tests: explicitly skip `chmod` calls on Windows
 4:  4d24a4345ba ! 3:  f96d5ab484c add -p: avoid ambiguous signed/unsigned comparison
     @@ Commit message
          Let's avoid that by converting the unsigned bit explicitly to a signed
          integer.
      
     +    Note: This is a long-standing bug in the Visual C build of Git, but it
     +    has never been caught because t3701 is skipped when `NO_PERL` is set,
     +    which is the case in the `vs-test` jobs of Git's CI runs.
     +
          Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
      
       ## add-patch.c ##
 5:  c7fc5a4ee4c = 4:  22473d6b8f3 cmake: avoid editing t/test-lib.sh
 -:  ----------- > 5:  6aaa675301c cmake: increase time-out for a long-running test