windows: Properly expand all environment variables

src/fileops.c

@@ -354,110 +354,22 @@ int git_futils_rmdir_r(const char *path, git_directory_removal_type removal_type
 }
 
 #ifdef GIT_WIN32
-static char *win32_getenv(const wchar_t *name)
-{
-	char *val_utf8;
-	wchar_t *val_utf16;
-	DWORD len = GetEnvironmentVariableW(name, NULL, 0);
-
-	if (len <= 0)
-		return NULL;
-
-	val_utf16 = git__calloc(len, sizeof(wchar_t));
-	if (!val_utf16)
-		return NULL;
-
-	if (GetEnvironmentVariableW(name, val_utf16, len) != len - 1) {
-		giterr_set(GITERR_OS, "Could not read environment variable");
-		git__free(val_utf16);
-		return NULL;
-	}
-
-	val_utf8 = gitwin_from_utf16(val_utf16);
-
-	git__free(val_utf16);
-
-	return val_utf8;
-}
-#endif
-
-int git_futils_find_global_file(git_buf *path, const char *filename)
-{
-	char *home;
-
-#ifdef GIT_WIN32
-	home = win32_getenv(L"HOME");
-
-	if (!home)
-		home = win32_getenv(L"USERPROFILE");
-
-	if (home)
-		git_path_mkposix(home);
-#else
-	home = getenv("HOME");
-#endif
-
-	if (home == NULL) {
-		giterr_set(GITERR_OS, "Global file lookup failed. "
-			"Cannot locate the user's home directory");
-		return -1;
-	}
-
-	if (git_buf_joinpath(path, home, filename) < 0)
-		return -1;
-
-#ifdef GIT_WIN32
-	git__free(home);
-#endif
-
-	if (git_path_exists(path->ptr) == false) {
-		git_buf_clear(path);
-		return GIT_ENOTFOUND;
-	}
-
-	return 0;
-}
-
-#ifdef GIT_WIN32
-typedef struct {
-	wchar_t *path;
+struct win32_path {
+	wchar_t path[MAX_PATH];
 	DWORD len;
-} win32_path;
+};
 
-static const win32_path *win32_system_root(void)
+static int win32_expand_path(struct win32_path *s_root, const wchar_t *templ)
 {
-	static win32_path s_root = { 0, 0 };
-
-	if (s_root.path == NULL) {
-		const wchar_t *root_tmpl = L"%PROGRAMFILES%\\Git\\etc\\";
-
-		s_root.len = ExpandEnvironmentStringsW(root_tmpl, NULL, 0);
-		if (s_root.len <= 0) {
-			giterr_set(GITERR_OS, "Failed to expand environment strings");
-			return NULL;
-		}
-
-		s_root.path = git__calloc(s_root.len, sizeof(wchar_t));
-		if (s_root.path == NULL)
-			return NULL;
-
-		if (ExpandEnvironmentStringsW(root_tmpl, s_root.path, s_root.len) != s_root.len) {
-			giterr_set(GITERR_OS, "Failed to expand environment strings");
-			git__free(s_root.path);
-			s_root.path = NULL;
-			return NULL;
-		}
-	}
-
-	return &s_root;
+	s_root->len = ExpandEnvironmentStringsW(templ, s_root->path, MAX_PATH);
+	return s_root->len ? 0 : -1;
 }
 
-static int win32_find_system_file(git_buf *path, const char *filename)
+static int win32_find_file(git_buf *path, const struct win32_path *root, const char *filename)
 {
 	int error = 0;
-	const win32_path *root = win32_system_root();
 	size_t len;
-	wchar_t *file_utf16 = NULL, *scan;
+	wchar_t *file_utf16 = NULL;
 	char *file_utf8 = NULL;
 
 	if (!root || !filename || (len = strlen(filename)) == 0)
@@ -479,10 +391,6 @@ static int win32_find_system_file(git_buf *path, const char *filename)
 		goto cleanup;
 	}
 
-	for (scan = file_utf16; *scan; scan++)
-		if (*scan == L'/')
-			*scan = L'\\';
-
 	/* check access */
 	if (_waccess(file_utf16, F_OK) < 0) {
 		error = GIT_ENOTFOUND;
@@ -499,13 +407,24 @@ static int win32_find_system_file(git_buf *path, const char *filename)
 
 cleanup:
 	git__free(file_utf16);
-
 	return error;
 }
 #endif
 
 int git_futils_find_system_file(git_buf *path, const char *filename)
 {
+#ifdef GIT_WIN32
+	struct win32_path root;
+	
+	if (win32_expand_path(&root, L"%PROGRAMFILES%\\Git\\etc\\") < 0 ||
+		win32_find_file(path, &root, filename) < 0) {
+		giterr_set(GITERR_OS, "Cannot find the system's Program Files directory");
+		return -1;
+	}
+
+	return 0;
+
+#else
 	if (git_buf_joinpath(path, "/etc", filename) < 0)
 		return -1;
 
@@ -513,10 +432,39 @@ int git_futils_find_system_file(git_buf *path, const char *filename)
 		return 0;
 
 	git_buf_clear(path);
+	return GIT_ENOTFOUND;
+#endif
+}
 
+int git_futils_find_global_file(git_buf *path, const char *filename)
+{
 #ifdef GIT_WIN32
-	return win32_find_system_file(path, filename);
+	struct win32_path root;
+
+	if (win32_expand_path(&root, L"%USERPROFILE%\\") < 0 ||
+		win32_find_file(path, &root, filename) < 0) {
+		giterr_set(GITERR_OS, "Failed to lookup the current user's Windows profile");
+		return -1;
+	}
+
+	return 0;
 #else
-	return GIT_ENOTFOUND;
+	const char *home = getenv("HOME");
+
+	if (home == NULL) {
+		giterr_set(GITERR_OS, "Global file lookup failed. "
+			"Cannot locate the user's home directory");
+		return -1;
+	}
+
+	if (git_buf_joinpath(path, home, filename) < 0)
+		return -1;
+
+	if (git_path_exists(path->ptr) == false) {
+		git_buf_clear(path);
+		return GIT_ENOTFOUND;
+	}
+
+	return 0;
 #endif
 }