[PATCH] Allow built-ins to also use -c var=val via alias

The previous commit 2b64fc8 (pass "git -c foo=bar" params through environment, 2010-08-23) tried to make all the one-shot configuration setting made via the "-c" option to the "git" wrapper go through an environment variable, so that the value can be propagated to external commands _as well as_ the internal ones, but ended up breaking one of the codepaths that invokes internal commands, because it incorrectly assumed that git_config_from_parmeters() can never be called in a single process after git_config_parse_environment() was called once.

Not so.

When the options came as part of an alias to an internal command, e.g.

  [alias]
    aw = -c apply.whitespace=fix apply

and then run as "git aw P.diff", we have already read the configuration to find out about the alias definition (setting loaded_environment to true), then pushed apply.whitespace=fix to the environment, but not to the in-core list of configuration variables. The implementation of the internal command, e.g. cmd_apply(), will try to read from git_config() but the setting is lost, as the environment is never read in this codepath.

Add the in-core queuing of the parameters back to fix this.

Note that the handling of such an alias is still broken for another reason in this codepath; a separate patch fixes it.

While at it, avoid getting our test confused by GIT_CONFIG_PARAMETERS exported to the tester's environment.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

 * And this is the other fix. Applying this on top of 2b64fc8 does not
   make "git aw P.diff" in the test t1300 in the other patch, but this
   is prerequisite for the other fix to work in a more modern codebase.

 config.c      |    1 +
 t/test-lib.sh |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)