DecoderPlugin: free the container_scan() return value with delete[]

src/db/update/Container.cxx

@@ -34,8 +34,6 @@
 
 #include <sys/stat.h>
 
-#include <glib.h>
-
 Directory *
 UpdateWalk::MakeDirectoryIfModified(Directory &parent, const char *name,
 				    const FileInfo &info)
@@ -120,7 +118,7 @@ UpdateWalk::UpdateContainerFile(Directory &directory,
 
 		FormatDefault(update_domain, "added %s/%s",
 			      directory.GetPath(), vtrack);
-		g_free(vtrack);
+		delete[] vtrack;
 	}
 
 	if (tnum == 1) {

src/decoder/DecoderPlugin.hxx

@@ -95,6 +95,8 @@ struct DecoderPlugin {
 	 * @return nullptr if there are no multiple files
 	 * a filename for every single track according to tnum (param 2)
 	 * do not include full pathname here, just the "virtual" file
+	 *
+	 * Free the return value with delete[].
 	 */
 	char* (*container_scan)(Path path_fs, const unsigned int tnum);
 

src/decoder/plugins/SidplayDecoderPlugin.cxx

@@ -22,7 +22,7 @@
 #include "../DecoderAPI.hxx"
 #include "tag/TagHandler.hxx"
 #include "fs/Path.hxx"
-#include "util/Alloc.hxx"
+#include "util/FormatString.hxx"
 #include "util/Domain.hxx"
 #include "system/ByteOrder.hxx"
 #include "Log.hxx"
@@ -406,9 +406,7 @@ sidplay_container_scan(Path path_fs, const unsigned int tnum)
 	/* Construct container/tune path names, eg.
 		Delta.sid/tune_001.sid */
 	if(tnum<=info.songs) {
-		char *subtune= g_strdup_printf(
-			SUBTUNE_PREFIX "%03u.sid", tnum);
-		return subtune;
+		return FormatNew(SUBTUNE_PREFIX "%03u.sid", tnum);
 	} else
 		return nullptr;
 }