t1300: make tests more robust with non-default ref backends

The t1300 test suite exercises the git-config(1) tool. To do so, the
test overwrites ".git/config" to contain custom contents in several
places with code like the following:

```
cat > .git/config <<\EOF
...
EOF
```

While this is easy enough to do, it may create problems when using a
non-default repository format because this causes us to overwrite the
repository format version as well as any potential extensions. With the
upcoming "reftable" ref backend the result is that Git would try to
access refs via the "files" backend even though the repository has been
initialized with the "reftable" backend, which will cause failures when
trying to access any refs.

Ideally, we would rewrite the whole test suite to not depend on state
written by previous tests, but that would result in a lot of changes in
this test suite. Instead, we only refactor tests which access the refdb
to be more robust by using their own separate repositories, which allows
us to be more careful and not discard required extensions.

Note that we also have to touch up how the CUSTOM_CONFIG_FILE gets
accessed. This environment variable contains the relative path to a
custom config file which we're setting up. But because we are now using
subrepositories, this relative path will not be found anymore because
our working directory changes. This issue is addressed by storing the
absolute path to the file in CUSTOM_CONFIG_FILE instead.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

0 files changed, 0 insertions, 0 deletions