Merge pull request git-for-windows#3472 from dscho/expand-runtime-prefix

Re-do the path interpolation support regarding RUNTIME_PREFIX

Author: dscho

Documentation/config.txt

@@ -298,6 +298,15 @@ pathname::
 	tilde expansion happens to such a string: `~/`
 	is expanded to the value of `$HOME`, and `~user/` to the
 	specified user's home directory.
++
+If a path starts with `%(prefix)/`, the remainder is interpreted as a
+path relative to Git's "runtime prefix", i.e. relative to the location
+where Git itself was installed. For example, `%(prefix)/bin/` refers to
+the directory in which the Git executable itself lives. If Git was
+compiled without runtime prefix support, the compiled-in prefix will be
+subsituted instead. In the unlikely event that a literal path needs to
+be specified that should _not_ be expanded, it needs to be prefixed by
+`./`, like so: `./%(prefix)/bin`.
 
 
 Variables

builtin/credential-cache.c

@@ -90,7 +90,7 @@ static char *get_socket_path(void)
 {
 	struct stat sb;
 	char *old_dir, *socket;
-	old_dir = expand_user_path("~/.git-credential-cache", 0);
+	old_dir = interpolate_path("~/.git-credential-cache", 0);
 	if (old_dir && !stat(old_dir, &sb) && S_ISDIR(sb.st_mode))
 		socket = xstrfmt("%s/socket", old_dir);
 	else

builtin/credential-store.c

@@ -176,7 +176,7 @@ int cmd_credential_store(int argc, const char **argv, const char *prefix)
 	if (file) {
 		string_list_append(&fns, file);
 	} else {
-		if ((file = expand_user_path("~/.git-credentials", 0)))
+		if ((file = interpolate_path("~/.git-credentials", 0)))
 			string_list_append_nodup(&fns, file);
 		file = xdg_config_home("credentials");
 		if (file)

builtin/gc.c

@@ -1542,7 +1542,7 @@ static char *launchctl_service_filename(const char *name)
 	struct strbuf filename = STRBUF_INIT;
 	strbuf_addf(&filename, "~/Library/LaunchAgents/%s.plist", name);
 
-	expanded = expand_user_path(filename.buf, 1);
+	expanded = interpolate_path(filename.buf, 1);
 	if (!expanded)
 		die(_("failed to expand path '%s'"), filename.buf);
 

cache.h

@@ -1253,7 +1253,9 @@ typedef int create_file_fn(const char *path, void *cb);
 int raceproof_create_file(const char *path, create_file_fn fn, void *cb);
 
 int mkdir_in_gitdir(const char *path);
-char *expand_user_path(const char *path, int real_home);
+char *interpolate_path(const char *path, int real_home);
+/* NEEDSWORK: remove this synonym once in-flight topics have migrated */
+#define expand_user_path interpolate_path
 const char *enter_repo(const char *path, int strict);
 static inline int is_absolute_path(const char *path)
 {

config.c

@@ -136,7 +136,7 @@ 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, 0);
+	expanded = interpolate_path(path, 0);
 	if (!expanded)
 		return error(_("could not expand include path '%s'"), path);
 	path = expanded;
@@ -184,7 +184,7 @@ static int prepare_include_condition_pattern(struct strbuf *pat)
 	char *expanded;
 	int prefix = 0;
 
-	expanded = expand_user_path(pat->buf, 1);
+	expanded = interpolate_path(pat->buf, 1);
 	if (expanded) {
 		strbuf_reset(pat);
 		strbuf_addstr(pat, expanded);
@@ -1269,7 +1269,7 @@ 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, 0);
+	*dest = interpolate_path(value, 0);
 	if (!*dest)
 		die(_("failed to expand user dir in: '%s'"), value);
 	return 0;
@@ -1842,7 +1842,7 @@ void git_global_config(char **user_out, char **xdg_out)
 	char *xdg_config = NULL;
 
 	if (!user_config) {
-		user_config = expand_user_path("~/.gitconfig", 0);
+		user_config = interpolate_path("~/.gitconfig", 0);
 		xdg_config = xdg_config_home("config");
 	}
 

path.c

@@ -720,22 +720,30 @@ 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.
+ * Return a string with ~ and ~user expanded via getpw*. Returns NULL on getpw
+ * failure or if path is NULL.
  *
- * If real_home is true, strbuf_realpath($HOME) is used in the expansion.
+ * If real_home is true, strbuf_realpath($HOME) is used in the `~/` expansion.
+ *
+ * If the path starts with `%(prefix)/`, the remainder is interpreted as
+ * relative to where Git is installed, and expanded to the absolute path.
  */
-char *expand_user_path(const char *path, int real_home)
+char *interpolate_path(const char *path, int real_home)
 {
 	struct strbuf user_path = STRBUF_INIT;
 	const char *to_copy = path;
 
 	if (path == NULL)
 		goto return_null;
+
+	if (skip_prefix(path, "%(prefix)/", &path))
+		return system_path(path);
+
 #ifdef __MINGW32__
-	if (path[0] == '/')
+	if (path[0] == '/') {
+		warning(_("encountered old-style '%s' that should be '%%(prefix)%s'"), path, path);
 		return system_path(path + 1);
+	}
 #endif
 	if (path[0] == '~') {
 		const char *first_slash = strchrnul(path, '/');
@@ -817,7 +825,7 @@ 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, 0);
+			char *newpath = interpolate_path(used_path.buf, 0);
 			if (!newpath)
 				return NULL;
 			strbuf_attach(&used_path, newpath, strlen(newpath),

sequencer.c

@@ -1242,7 +1242,7 @@ N_("Your name and email address were configured automatically based\n"
 
 static const char *implicit_ident_advice(void)
 {
-	char *user_config = expand_user_path("~/.gitconfig", 0);
+	char *user_config = interpolate_path("~/.gitconfig", 0);
 	char *xdg_config = xdg_config_home("config");
 	int config_exists = file_exists(user_config) || file_exists(xdg_config);
 

t/t0060-path-utils.sh

@@ -525,6 +525,32 @@ test_expect_success MINGW 'is_valid_path() on Windows' '
 		"PRN./abc"
 '
 
+test_lazy_prereq RUNTIME_PREFIX '
+	test true = "$RUNTIME_PREFIX"
+'
+
+test_lazy_prereq CAN_EXEC_IN_PWD '
+	cp "$GIT_EXEC_PATH"/git$X ./ &&
+	./git rev-parse
+'
+
+test_expect_success RUNTIME_PREFIX,CAN_EXEC_IN_PWD 'RUNTIME_PREFIX works' '
+	mkdir -p pretend/bin pretend/libexec/git-core &&
+	echo "echo HERE" | write_script pretend/libexec/git-core/git-here &&
+	cp "$GIT_EXEC_PATH"/git$X pretend/bin/ &&
+	GIT_EXEC_PATH= ./pretend/bin/git here >actual &&
+	echo HERE >expect &&
+	test_cmp expect actual'
+
+test_expect_success RUNTIME_PREFIX,CAN_EXEC_IN_PWD '%(prefix)/ works' '
+	mkdir -p pretend/bin &&
+	cp "$GIT_EXEC_PATH"/git$X pretend/bin/ &&
+	git config yes.path "%(prefix)/yes" &&
+	GIT_EXEC_PATH= ./pretend/bin/git config --path yes.path >actual &&
+	echo "$(pwd)/pretend/yes" >expect &&
+	test_cmp expect actual
+'
+
 test_expect_success MINGW 'MSYSTEM/PATH is adjusted if necessary' '
 	mkdir -p "$HOME"/bin pretend/mingw64/bin \
 		pretend/mingw64/libexec/git-core pretend/usr/bin &&
@@ -545,22 +571,4 @@ test_expect_success MINGW 'MSYSTEM/PATH is adjusted if necessary' '
 	test_cmp expect actual
 '
 
-test_lazy_prereq RUNTIME_PREFIX '
-	test true = "$RUNTIME_PREFIX"
-'
-
-test_lazy_prereq CAN_EXEC_IN_PWD '
-	cp "$GIT_EXEC_PATH"/git$X ./ &&
-	./git rev-parse
-'
-
-test_expect_success RUNTIME_PREFIX,CAN_EXEC_IN_PWD 'RUNTIME_PREFIX works' '
-	mkdir -p pretend/git pretend/libexec/git-core &&
-	echo "echo HERE" | write_script pretend/libexec/git-core/git-here &&
-	cp "$GIT_EXEC_PATH"/git$X pretend/git/ &&
-	GIT_EXEC_PATH= ./pretend/git/git here >actual &&
-	echo HERE >expect &&
-	test_cmp expect actual
-'
-
 test_done