path.c: and an option to call real_path() in expand_user_path()

In the next patch we need the ability to expand '~' to
real_path($HOME). But we can't do that from outside because '~' is part
of a pattern, not a true path. Add an option to expand_user_path() to do
so.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/commit.c

@@ -1404,7 +1404,7 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 
 static const char *implicit_ident_advice(void)
 {
-	char *user_config = expand_user_path("~/.gitconfig");
+	char *user_config = expand_user_path("~/.gitconfig", 0);
 	char *xdg_config = xdg_config_home("config");
 	int config_exists = file_exists(user_config) || file_exists(xdg_config);
 

builtin/config.c

@@ -502,7 +502,7 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	}
 
 	if (use_global_config) {
-		char *user_config = expand_user_path("~/.gitconfig");
+		char *user_config = expand_user_path("~/.gitconfig", 0);
 		char *xdg_config = xdg_config_home("config");
 
 		if (!user_config)

cache.h

@@ -1098,7 +1098,7 @@ enum scld_error safe_create_leading_directories(char *path);
 enum scld_error safe_create_leading_directories_const(const char *path);
 
 int mkdir_in_gitdir(const char *path);
-extern char *expand_user_path(const char *path);
+extern char *expand_user_path(const char *path, int real_home);
 const char *enter_repo(const char *path, int strict);
 static inline int is_absolute_path(const char *path)
 {

config.c

@@ -135,7 +135,7 @@ static int handle_path_include(const char *path, struct config_include_data *inc
 	if (!path)
 		return config_error_nonbool("include.path");
 
-	expanded = expand_user_path(path);
+	expanded = expand_user_path(path, 0);
 	if (!expanded)
 		return error("could not expand include path '%s'", path);
 	path = expanded;
@@ -177,7 +177,7 @@ static int prepare_include_condition_pattern(struct strbuf *pat)
 	char *expanded;
 	int prefix = 0;
 
-	expanded = expand_user_path(pat->buf);
+	expanded = expand_user_path(pat->buf, 0);
 	if (expanded) {
 		strbuf_reset(pat);
 		strbuf_addstr(pat, expanded);
@@ -857,7 +857,7 @@ int git_config_pathname(const char **dest, const char *var, const char *value)
 {
 	if (!value)
 		return config_error_nonbool(var);
-	*dest = expand_user_path(value);
+	*dest = expand_user_path(value, 0);
 	if (!*dest)
 		die(_("failed to expand user dir in: '%s'"), value);
 	return 0;
@@ -1407,7 +1407,7 @@ static int do_git_config_sequence(config_fn_t fn, void *data)
 {
 	int ret = 0;
 	char *xdg_config = xdg_config_home("config");
-	char *user_config = expand_user_path("~/.gitconfig");
+	char *user_config = expand_user_path("~/.gitconfig", 0);
 	char *repo_config = have_git_dir() ? git_pathdup("config") : NULL;
 
 	current_parsing_scope = CONFIG_SCOPE_SYSTEM;

credential-cache.c

@@ -106,7 +106,7 @@ int cmd_main(int argc, const char **argv)
 	op = argv[0];
 
 	if (!socket_path)
-		socket_path = expand_user_path("~/.git-credential-cache/socket");
+		socket_path = expand_user_path("~/.git-credential-cache/socket", 0);
 	if (!socket_path)
 		die("unable to find a suitable socket path; use --socket");
 

credential-store.c

@@ -168,7 +168,7 @@ int cmd_main(int argc, const char **argv)
 	if (file) {
 		string_list_append(&fns, file);
 	} else {
-		if ((file = expand_user_path("~/.git-credentials")))
+		if ((file = expand_user_path("~/.git-credentials", 0)))
 			string_list_append_nodup(&fns, file);
 		file = xdg_config_home("credentials");
 		if (file)

path.c

@@ -638,8 +638,10 @@ static struct passwd *getpw_str(const char *username, size_t len)
  * Return a string with ~ and ~user expanded via getpw*.  If buf != NULL,
  * then it is a newly allocated string. Returns NULL on getpw failure or
  * if path is NULL.
+ *
+ * If real_home is true, real_path($HOME) is used in the expansion.
  */
-char *expand_user_path(const char *path)
+char *expand_user_path(const char *path, int real_home)
 {
 	struct strbuf user_path = STRBUF_INIT;
 	const char *to_copy = path;
@@ -654,6 +656,9 @@ char *expand_user_path(const char *path)
 			const char *home = getenv("HOME");
 			if (!home)
 				goto return_null;
+			if (real_home)
+				strbuf_addstr(&user_path, real_path(home));
+			else
 				strbuf_addstr(&user_path, home);
 #ifdef GIT_WINDOWS_NATIVE
 			convert_slashes(user_path.buf);
@@ -723,7 +728,7 @@ const char *enter_repo(const char *path, int strict)
 		strbuf_add(&validated_path, path, len);
 
 		if (used_path.buf[0] == '~') {
-			char *newpath = expand_user_path(used_path.buf);
+			char *newpath = expand_user_path(used_path.buf, 0);
 			if (!newpath)
 				return NULL;
 			strbuf_attach(&used_path, newpath, strlen(newpath),