handle_alias: provide GIT_PREFIX to !alias

Provide an environment variable GIT_PREFIX which contains the subdirectory
from which a !alias was called (i.e. 'git rev-parse --show-prefix') since
these cd to the to level directory before they are executed.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/git.c b/git.c
index ef598c3e70..ed899512f9 100644
--- a/git.c
+++ b/git.c
@@ -179,6 +179,8 @@ static int handle_alias(int *argcp, const char ***argv)
 		if (alias_string[0] == '!') {
 			const char **alias_argv;
 			int argc = *argcp, i;
+			struct strbuf sb = STRBUF_INIT;
+			const char *env[2];
 
 			commit_pager_choice();
 
@@ -189,7 +191,13 @@ static int handle_alias(int *argcp, const char ***argv)
 				alias_argv[i] = (*argv)[i];
 			alias_argv[argc] = NULL;
 
-			ret = run_command_v_opt(alias_argv, RUN_USING_SHELL);
+			strbuf_addstr(&sb, "GIT_PREFIX=");
+			if (subdir)
+				strbuf_addstr(&sb, subdir);
+			env[0] = sb.buf;
+			env[1] = NULL;
+			ret = run_command_v_opt_cd_env(alias_argv, RUN_USING_SHELL, NULL, env);
+			strbuf_release(&sb);
 			if (ret >= 0)   /* normal exit */
 				exit(ret);