fs/NarrowPath: new utility class

Makefile.am

@@ -559,6 +559,7 @@ libfs_a_SOURCES = \
 	src/fs/Charset.cxx src/fs/Charset.hxx \
 	src/fs/Path.cxx src/fs/Path2.cxx src/fs/Path.hxx \
 	src/fs/AllocatedPath.cxx src/fs/AllocatedPath.hxx \
+	src/fs/NarrowPath.hxx \
 	src/fs/FileSystem.cxx src/fs/FileSystem.hxx \
 	src/fs/FileInfo.hxx \
 	src/fs/StandardDirectory.cxx src/fs/StandardDirectory.hxx \

src/PlaylistSave.cxx

@@ -29,6 +29,7 @@
 #include "fs/AllocatedPath.hxx"
 #include "fs/Traits.hxx"
 #include "fs/FileSystem.hxx"
+#include "fs/NarrowPath.hxx"
 #include "util/Alloc.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Error.hxx"
@@ -45,7 +46,7 @@ playlist_print_song(FILE *file, const DetachedSong &song)
 
 	const auto uri_fs = AllocatedPath::FromUTF8(uri_utf8);
 	if (!uri_fs.IsNull())
-		fprintf(file, "%s\n", uri_fs.c_str());
+		fprintf(file, "%s\n", NarrowPath(uri_fs).c_str());
 }
 
 void
@@ -61,7 +62,7 @@ playlist_print_uri(FILE *file, const char *uri)
 		AllocatedPath::FromUTF8(uri);
 
 	if (!path.IsNull())
-		fprintf(file, "%s\n", path.c_str());
+		fprintf(file, "%s\n", NarrowPath(path).c_str());
 }
 
 PlaylistResult

src/decoder/plugins/FlacDecoderPlugin.cxx

@@ -24,6 +24,7 @@
 #include "FlacMetadata.hxx"
 #include "OggCodec.hxx"
 #include "fs/Path.hxx"
+#include "fs/NarrowPath.hxx"
 #include "util/Error.hxx"
 #include "Log.hxx"
 
@@ -84,7 +85,7 @@ flac_scan_file(Path path_fs,
 	       const struct tag_handler *handler, void *handler_ctx)
 {
 	FlacMetadataChain chain;
-	if (!chain.Read(path_fs.c_str())) {
+	if (!chain.Read(NarrowPath(path_fs))) {
 		FormatDebug(flac_domain,
 			    "Failed to read FLAC tags: %s",
 			    chain.GetStatusString());
@@ -301,7 +302,7 @@ oggflac_scan_file(Path path_fs,
 		  const struct tag_handler *handler, void *handler_ctx)
 {
 	FlacMetadataChain chain;
-	if (!chain.ReadOgg(path_fs.c_str())) {
+	if (!chain.ReadOgg(NarrowPath(path_fs))) {
 		FormatDebug(flac_domain,
 			    "Failed to read OggFLAC tags: %s",
 			    chain.GetStatusString());

src/fs/NarrowPath.hxx

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2003-2015 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_FS_NARROW_PATH_HXX
+#define MPD_FS_NARROW_PATH_HXX
+
+#include "check.h"
+#include "Path.hxx"
+
+/**
+ * A path name that uses the regular (narrow) "char".  This is used to
+ * pass a #Path (which may be represented by wchar_t) to a library
+ * that accepts only "const char *".
+ */
+class NarrowPath {
+	typedef char value_type;
+	typedef const char *const_pointer;
+
+	const_pointer value;
+
+public:
+	explicit NarrowPath(Path _path):value(_path.c_str()) {}
+
+	operator const_pointer() const {
+		return value;
+	}
+
+	const_pointer c_str() const {
+		return value;
+	}
+};
+
+#endif