ClientFile: use Path and file system API, update usages accordingly

This commit also fixes incorrect passing of UTF-8 strings to client_allow_file

src/ClientFile.cxx

@@ -22,6 +22,8 @@
 #include "Client.hxx"
 #include "ack.h"
 #include "io_error.h"
+#include "fs/Path.hxx"
+#include "fs/FileSystem.hxx"
 
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -29,7 +31,7 @@
 #include <unistd.h>
 
 bool
-client_allow_file(const Client *client, const char *path_fs,
+client_allow_file(const Client *client, const Path &path_fs,
 		  GError **error_r)
 {
 #ifdef WIN32
@@ -54,7 +56,7 @@ client_allow_file(const Client *client, const char *path_fs,
 	}
 
 	struct stat st;
-	if (stat(path_fs, &st) < 0) {
+	if (!StatFile(path_fs, st)) {
 		set_error_errno(error_r);
 		return false;
 	}

src/ClientFile.hxx

@@ -25,6 +25,7 @@
 #include <stdbool.h>
 
 class Client;
+class Path;
 
 /**
  * Is this client allowed to use the specified local file?
@@ -37,7 +38,7 @@ class Client;
  * @return true if access is allowed
  */
 bool
-client_allow_file(const Client *client, const char *path_fs,
+client_allow_file(const Client *client, const Path &path_fs,
 		  GError **error_r);
 
 #endif

src/OtherCommands.cxx

@@ -34,6 +34,7 @@
 #include "ls.hxx"
 #include "Volume.hxx"
 #include "util/UriUtil.hxx"
+#include "fs/Path.hxx"
 
 extern "C" {
 #include "stats.h"
@@ -117,9 +118,16 @@ handle_lsinfo(Client *client, int argc, char *argv[])
 	if (strncmp(uri, "file:///", 8) == 0) {
 		/* print information about an arbitrary local file */
 		const char *path_utf8 = uri + 7;
+		const Path path_fs = Path::FromUTF8(path_utf8);
+
+		if (path_fs.IsNull()) {
+			command_error(client, ACK_ERROR_NO_EXIST,
+				      "unsupported file name");
+			return COMMAND_RETURN_ERROR;
+		}
 
 		GError *error = NULL;
-		if (!client_allow_file(client, path_utf8, &error))
+		if (!client_allow_file(client, path_fs, &error))
 			return print_error(client, error);
 
 		struct song *song = song_file_load(path_utf8, NULL);

src/QueueCommands.cxx

@@ -32,6 +32,7 @@
 #include "protocol/Result.hxx"
 #include "ls.hxx"
 #include "util/UriUtil.hxx"
+#include "fs/Path.hxx"
 
 #include <string.h>
 
@@ -42,13 +43,20 @@ handle_add(Client *client, G_GNUC_UNUSED int argc, char *argv[])
 	enum playlist_result result;
 
 	if (strncmp(uri, "file:///", 8) == 0) {
-		const char *path = uri + 7;
+		const char *path_utf8 = uri + 7;
+		const Path path_fs = Path::FromUTF8(path_utf8);
+
+		if (path_fs.IsNull()) {
+			command_error(client, ACK_ERROR_NO_EXIST,
+				      "unsupported file name");
+			return COMMAND_RETURN_ERROR;
+		}
 
 		GError *error = NULL;
-		if (!client_allow_file(client, path, &error))
+		if (!client_allow_file(client, path_fs, &error))
 			return print_error(client, error);
 
-		result = client->partition.AppendFile(path);
+		result = client->partition.AppendFile(path_utf8);
 		return print_playlist_result(client, result);
 	}
 
@@ -78,13 +86,20 @@ handle_addid(Client *client, int argc, char *argv[])
 	enum playlist_result result;
 
 	if (strncmp(uri, "file:///", 8) == 0) {
-		const char *path = uri + 7;
+		const char *path_utf8 = uri + 7;
+		const Path path_fs = Path::FromUTF8(path_utf8);
+
+		if (path_fs.IsNull()) {
+			command_error(client, ACK_ERROR_NO_EXIST,
+				      "unsupported file name");
+			return COMMAND_RETURN_ERROR;
+		}
 
 		GError *error = NULL;
-		if (!client_allow_file(client, path, &error))
+		if (!client_allow_file(client, path_fs, &error))
 			return print_error(client, error);
 
-		result = client->partition.AppendFile(path, &added_id);
+		result = client->partition.AppendFile(path_utf8, &added_id);
 	} else {
 		if (uri_has_scheme(uri) && !uri_supported_scheme(uri)) {
 			command_error(client, ACK_ERROR_NO_EXIST,