config: unify code paths to get global config paths

There's two callsites which assemble global config paths, once in the
config loading code and once in the git-config(1) builtin. We're about
to implement a way to override global config paths via an environment
variable which would require us to adjust both sites.

Unify both code paths into a single `git_global_config()` function which
returns both paths for `~/.gitconfig` and the XDG config file. This will
make the subsequent patch which introduces the new envvar easier to
implement.

No functional changes are expected from this patch.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/config.h b/config.h
index 2be8fa1880..9038538ffd 100644
--- a/config.h
+++ b/config.h
@@ -327,6 +327,7 @@ int config_error_nonbool(const char *);
 #endif
 
 char *git_system_config(void);
+void git_global_config(char **user, char **xdg);
 
 int git_config_parse_parameter(const char *, config_fn_t fn, void *data);