PlaylistFile, client_file, tag_id3: don't use g_file_error_quark()

g_file_error_quark() is meant to be used with the GFileError enum
which does not correspond with errno, but must be converted with
g_file_error_from_errno().

At the same time, this removes g_strerror() use for
g_file_error_quark().

Makefile.am

@@ -295,6 +295,7 @@ src_mpd_SOURCES = \
 	src/listen.c \
 	src/log.c \
 	src/ls.c \
+	src/io_error.h \
 	src/io_thread.c src/io_thread.h \
 	src/Main.cxx src/Main.hxx \
 	src/Win32Main.cxx \

src/CommandError.cxx

@@ -20,6 +20,7 @@
 #include "config.h"
 #include "CommandError.hxx"
 #include "db_error.h"
+#include "io_error.h"
 
 extern "C" {
 #include "protocol/result.h"
@@ -119,11 +120,15 @@ print_error(struct client *client, GError *error)
 			command_error(client, ACK_ERROR_NO_EXIST, "Not found");
 			return COMMAND_RETURN_ERROR;
 		}
-	} else if (error->domain == g_file_error_quark()) {
+	} else if (error->domain == errno_quark()) {
 		command_error(client, ACK_ERROR_SYSTEM, "%s",
 			      g_strerror(error->code));
 		g_error_free(error);
 		return COMMAND_RETURN_ERROR;
+	} else if (error->domain == g_file_error_quark()) {
+		command_error(client, ACK_ERROR_SYSTEM, "%s", error->message);
+		g_error_free(error);
+		return COMMAND_RETURN_ERROR;
 	}
 
 	g_error_free(error);

src/PlaylistFile.cxx

@@ -21,6 +21,7 @@
 #include "PlaylistFile.hxx"
 #include "PlaylistSave.hxx"
 #include "song.h"
+#include "io_error.h"
 
 extern "C" {
 #include "text_file.h"
@@ -132,8 +133,7 @@ playlist_errno(GError **error_r)
 		break;
 
 	default:
-		g_set_error_literal(error_r, g_file_error_quark(), errno,
-				    g_strerror(errno));
+		set_error_errno(error_r);
 		break;
 	}
 }
@@ -181,8 +181,7 @@ ListPlaylistFiles(GError **error_r)
 
 	DIR *dir = opendir(parent_path_fs);
 	if (dir == NULL) {
-		g_set_error_literal(error_r, g_file_error_quark(), errno,
-				    g_strerror(errno));
+		set_error_errno(error_r);
 		return list;
 	}
 

src/client_file.c

@@ -20,6 +20,7 @@
 #include "client_file.h"
 #include "client.h"
 #include "ack.h"
+#include "io_error.h"
 
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -53,8 +54,7 @@ client_allow_file(const struct client *client, const char *path_fs,
 
 	struct stat st;
 	if (stat(path_fs, &st) < 0) {
-		g_set_error(error_r, g_file_error_quark(), errno,
-			    "%s", g_strerror(errno));
+		set_error_errno(error_r);
 		return false;
 	}
 

src/io_error.h

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2003-2012 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_IO_ERROR_H
+#define MPD_IO_ERROR_H
+
+#include <glib.h>
+
+#include <errno.h>
+
+/**
+ * A GQuark for GError for I/O errors.  The code is an errno value.
+ */
+G_GNUC_CONST
+static inline GQuark
+errno_quark(void)
+{
+	return g_quark_from_static_string("errno");
+}
+
+static inline void
+set_error_errno(GError **error_r)
+{
+	g_set_error_literal(error_r, errno_quark(), errno,
+			    g_strerror(errno));
+}
+
+#endif

src/tag_id3.c

@@ -25,6 +25,7 @@
 #include "riff.h"
 #include "aiff.h"
 #include "conf.h"
+#include "io_error.h"
 
 #include <glib.h>
 #include <id3tag.h>
@@ -546,7 +547,7 @@ tag_id3_load(const char *path_fs, GError **error_r)
 {
 	FILE *file = fopen(path_fs, "rb");
 	if (file == NULL) {
-		g_set_error(error_r, g_file_error_quark(), errno,
+		g_set_error(error_r, errno_quark(), errno,
 			    "Failed to open file %s: %s",
 			    path_fs, g_strerror(errno));
 		return NULL;