Path: add FromUTF8() overload that returns an Error

src/ConfigPath.cxx

@@ -53,13 +53,9 @@ ParsePath(const char *path, Error &error)
 {
 	assert(path != nullptr);
 
-	Path path2 = Path::FromUTF8(path);
-	if (path2.IsNull()) {
-		error.Format(path_domain,
-			     "Failed to convert path to file system charset: %s",
-			     path);
+	Path path2 = Path::FromUTF8(path, error);
+	if (path2.IsNull())
 		return Path::Null();
-	}
 
 #ifndef WIN32
 	if (!g_path_is_absolute(path) && path[0] != '~') {

src/Main.cxx

@@ -138,8 +138,12 @@ glue_mapper_init(Error &error)
 	if (playlist_dir.IsNull() && error.IsDefined())
 		return false;
 
-	if (music_dir.IsNull())
-		music_dir = Path::FromUTF8(g_get_user_special_dir(G_USER_DIRECTORY_MUSIC));
+	if (music_dir.IsNull()) {
+		music_dir = Path::FromUTF8(g_get_user_special_dir(G_USER_DIRECTORY_MUSIC),
+					   error);
+		if (music_dir.IsNull())
+			return false;
+	}
 
 	mapper_init(std::move(music_dir), std::move(playlist_dir));
 	return true;

src/fs/Path.cxx

@@ -21,6 +21,7 @@
 #include "fs/Path.hxx"
 #include "ConfigGlobal.hxx"
 #include "system/FatalError.hxx"
+#include "util/Error.hxx"
 #include "util/Domain.hxx"
 #include "gcc.h"
 
@@ -89,6 +90,18 @@ Path Path::FromUTF8(const char *path_utf8)
 	return Path(Donate(), p);
 }
 
+Path
+Path::FromUTF8(const char *path_utf8, Error &error)
+{
+	Path path = FromUTF8(path_utf8);
+	if (path.IsNull())
+		error.Format(path_domain,
+			     "Failed to convert to file system charset: %s",
+			     path_utf8);
+
+	return path;
+}
+
 gcc_pure
 static bool
 IsSupportedCharset(const char *charset)

src/fs/Path.hxx

@@ -44,6 +44,8 @@
 #  endif
 #endif
 
+class Error;
+
 extern const class Domain path_domain;
 
 /**
@@ -151,6 +153,9 @@ public:
 	gcc_pure
 	static Path FromUTF8(const char *path_utf8);
 
+	gcc_pure
+	static Path FromUTF8(const char *path_utf8, Error &error);
+
 	/**
 	 * Convert the path to UTF-8.
 	 * Returns empty string on error or if #path_fs is null pointer.