Move code interpreting path relative to exec-dir to new function system_path()

Expanding system paths relative to git_exec_path can be used for
creating an installation that can be moved to a different directory
without re-compiling.  We use this approach for template_dir and the
system wide gitconfig.  The Windows installer (msysgit) is an example
for such a setup.

This commit moves common code to a new function system_path().  System
paths that are to be interpreted relative to git_exec_path are passed to
system_path() and the return value is used instead of the original path.
system_path() prefixes a relative path with git_exec_path and leaves
absolute paths unmodified.  For example, we now write

    template_dir = system_path(DEFAULT_GIT_TEMPLATE_DIR);

[j6t: moved from path.c to exec_cmd.c]

Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 9 deletions

diff --git a/config.c b/config.c
index 2862cc4..1e066c7 100644
--- a/config.c
+++ b/config.c
@@ -581,15 +581,8 @@ int git_config_from_file(config_fn_t fn, const char *filename, void *data)
 const char *git_etc_gitconfig(void)
 {
 	static const char *system_wide;
-	if (!system_wide) {
-		system_wide = ETC_GITCONFIG;
-		if (!is_absolute_path(system_wide)) {
-			/* interpret path relative to exec-dir */
-			struct strbuf d = STRBUF_INIT;
-			strbuf_addf(&d, "%s/%s", git_exec_path(), system_wide);
-			system_wide = strbuf_detach(&d, NULL);
-		}
-	}
+	if (!system_wide)
+		system_wide = system_path(ETC_GITCONFIG);
 	return system_wide;
 }