Record the command invocation path early

We will need the command invocation path in system_path(). This path was
passed to setup_path(), but  system_path() can be called earlier, for
example via:

    main
      commit_pager_choice
        setup_pager
          git_config
            git_etc_gitconfig
              system_path

Therefore, we introduce git_set_argv0_path() and call it as soon as
possible.

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

exec_cmd.c

@@ -5,6 +5,7 @@
 
 extern char **environ;
 static const char *argv_exec_path;
+static const char *argv0_path;
 
 static const char *builtin_exec_path(void)
 {
@@ -50,6 +51,11 @@ const char *system_path(const char *path)
 	return path;
 }
 
+void git_set_argv0_path(const char *path)
+{
+	argv0_path = path;
+}
+
 void git_set_argv_exec_path(const char *exec_path)
 {
 	argv_exec_path = exec_path;
@@ -84,7 +90,7 @@ static void add_path(struct strbuf *out, const char *path)
 	}
 }
 
-void setup_path(const char *cmd_path)
+void setup_path(void)
 {
 	const char *old_path = getenv("PATH");
 	struct strbuf new_path;
@@ -94,7 +100,7 @@ void setup_path(const char *cmd_path)
 	add_path(&new_path, argv_exec_path);
 	add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
 	add_path(&new_path, builtin_exec_path());
-	add_path(&new_path, cmd_path);
+	add_path(&new_path, argv0_path);
 
 	if (old_path)
 		strbuf_addstr(&new_path, old_path);

exec_cmd.h

@@ -2,8 +2,9 @@
 #define GIT_EXEC_CMD_H
 
 extern void git_set_argv_exec_path(const char *exec_path);
+extern void git_set_argv0_path(const char *path);
 extern const char* git_exec_path(void);
-extern void setup_path(const char *);
+extern void setup_path(void);
 extern int execv_git_cmd(const char **argv); /* NULL terminated */
 extern int execl_git_cmd(const char *cmd, ...);
 extern const char *system_path(const char *path);

git.c

@@ -418,7 +418,6 @@ int main(int argc, const char **argv)
 {
 	const char *cmd = argv[0] && *argv[0] ? argv[0] : "git-help";
 	char *slash = (char *)cmd + strlen(cmd);
-	const char *cmd_path = NULL;
 	int done_alias = 0;
 
 	/*
@@ -431,7 +430,7 @@ int main(int argc, const char **argv)
 	while (cmd <= slash && !is_dir_sep(*slash));
 	if (cmd <= slash) {
 		*slash++ = 0;
-		cmd_path = cmd;
+		git_set_argv0_path(cmd);
 		cmd = slash;
 	}
 
@@ -475,7 +474,7 @@ int main(int argc, const char **argv)
 	 * environment, and the $(gitexecdir) from the Makefile at build
 	 * time.
 	 */
-	setup_path(cmd_path);
+	setup_path();
 
 	while (1) {
 		/* See if it's an internal command */

receive-pack.c

@@ -482,7 +482,7 @@ int main(int argc, char **argv)
 	if (!dir)
 		usage(receive_pack_usage);
 
-	setup_path(NULL);
+	setup_path();
 
 	if (!enter_repo(dir, 0))
 		die("'%s': unable to chdir or not a git archive", dir);

shell.c

@@ -15,7 +15,7 @@ static int do_generic_cmd(const char *me, char *arg)
 {
 	const char *my_argv[4];
 
-	setup_path(NULL);
+	setup_path();
 	if (!arg || !(arg = sq_dequote(arg)))
 		die("bad argument");
 	if (prefixcmp(me, "git-"))
@@ -37,7 +37,7 @@ static int do_cvs_cmd(const char *me, char *arg)
 	if (!arg || strcmp(arg, "server"))
 		die("git-cvsserver only handles server: %s", arg);
 
-	setup_path(NULL);
+	setup_path();
 	return execv_git_cmd(cvsserver_argv);
 }
 

upload-pack.c

@@ -638,7 +638,7 @@ int main(int argc, char **argv)
 	if (i != argc-1)
 		usage(upload_pack_usage);
 
-	setup_path(NULL);
+	setup_path();
 
 	dir = argv[i];