moved fallback APE/ID3 tag loader to song.c

Some plugins used the APE or ID3 tag loader as a fallback when their
own methods of loading tags did not work.  Move this code out of all
decoder plugins, into song_file_update().

src/decoder/aac_plugin.c

@@ -443,19 +443,18 @@ aac_stream_decode(struct decoder *mpd_decoder, struct input_stream *inStream)
 
 static struct tag *aacTagDup(const char *file)
 {
-	struct tag *ret = NULL;
 	int file_time = getAacTotalTime(file);
+	struct tag *tag;
 
-	if (file_time >= 0) {
+	if (file_time < 0) {
-		if ((ret = tag_id3_load(file)) == NULL)
-			ret = tag_new();
-		ret->time = file_time;
-	} else {
 		g_debug("aacTagDup: Failed to get total song time from: %s\n",
 			file);
+		return NULL;
 	}
 
-	return ret;
+	tag = tag_new();
+	tag->time = file_time;
+	return tag;
 }
 
 static const char *const aac_suffixes[] = { "aac", NULL };

src/decoder/flac_plugin.c

@@ -282,23 +282,7 @@ flac_tag_load(const char *file)
 static struct tag *
 flac_tag_dup(const char *file)
 {
-	struct tag *ret = NULL;
+	return flac_tag_load(file);
-
-	ret = flac_tag_load(file);
-	if (!ret) {
-		g_debug("Failed to grab information from: %s\n", file);
-		return NULL;
-	}
-	if (tag_is_empty(ret)) {
-		struct tag *temp = tag_id3_load(file);
-		if (temp) {
-			temp->time = ret->time;
-			tag_free(ret);
-			ret = temp;
-		}
-	}
-
-	return ret;
 }
 
 static void

src/decoder/mp3_plugin.c

@@ -19,6 +19,7 @@
 #include "../decoder_api.h"
 #include "../conf.h"
 #include "config.h"
+#include "tag_id3.h"
 
 #include <assert.h>
 #include <unistd.h>
@@ -1190,22 +1191,19 @@ mp3_decode(struct decoder *decoder, struct input_stream *input_stream)
 
 static struct tag *mp3_tag_dup(const char *file)
 {
-	struct tag *ret = NULL;
+	struct tag *tag;
 	int total_time;
 
-	ret = tag_id3_load(file);
-
 	total_time = mp3_total_file_time(file);
-	if (total_time >= 0) {
+	if (total_time < 0) {
-		if (!ret)
-			ret = tag_new();
-		ret->time = total_time;
-	} else {
 		g_debug("mp3_tag_dup: Failed to get total song time from: %s\n",
 			file);
+		return NULL;
 	}
 
-	return ret;
+	tag = tag_new();
+	tag->time = total_time;
+	return tag;
 }
 
 static const char *const mp3_suffixes[] = { "mp3", "mp2", NULL };

src/decoder/mp4_plugin.c

@@ -405,21 +405,7 @@ mp4_load_tag(const char *file)
 static struct tag *
 mp4_tag_dup(const char *file)
 {
-	struct tag *ret = NULL;
+	return mp4_load_tag(file);
-
-	ret = mp4_load_tag(file);
-	if (!ret)
-		return NULL;
-	if (tag_is_empty(ret)) {
-		struct tag *temp = tag_id3_load(file);
-		if (temp) {
-			temp->time = ret->time;
-			tag_free(ret);
-			ret = temp;
-		}
-	}
-
-	return ret;
 }
 
 static const char *const mp4_suffixes[] = { "m4a", "mp4", NULL };

src/decoder/mpc_plugin.c

@@ -249,8 +249,8 @@ static float mpcGetTime(const char *file)
 
 static struct tag *mpcTagDup(const char *file)
 {
-	struct tag *ret = NULL;
 	float total_time = mpcGetTime(file);
+	struct tag *tag;
 
 	if (total_time < 0) {
 		g_debug("mpcTagDup: Failed to get Songlength of file: %s\n",
@@ -258,14 +258,9 @@ static struct tag *mpcTagDup(const char *file)
 		return NULL;
 	}
 
-	ret = tag_ape_load(file);
+	tag = tag_new();
-	if (!ret)
+	tag->time = total_time;
-		ret = tag_id3_load(file);
+	return tag;
-	if (!ret)
-		ret = tag_new();
-	ret->time = total_time;
-
-	return ret;
 }
 
 static const char *const mpcSuffixes[] = { "mpc", NULL };

src/decoder_api.h

@@ -29,7 +29,6 @@
 #include "input_stream.h"
 #include "replay_gain.h"
 #include "tag.h"
-#include "tag_id3.h"
 #include "audio_format.h"
 #include "playerData.h"
 

src/song.c

@@ -24,6 +24,7 @@
 #include "playlist.h"
 #include "decoder_list.h"
 #include "decoder_api.h"
+#include "tag_id3.h"
 
 #include <glib.h>
 
@@ -98,6 +99,38 @@ song_free(struct song *song)
 	g_free(song);
 }
 
+/**
+ * Attempts to load APE or ID3 tags from the specified file.
+ */
+static struct tag *
+tag_load_fallback(const char *path)
+{
+	struct tag *tag = tag_ape_load(path);
+	if (tag == NULL)
+		tag = tag_id3_load(path);
+	return tag;
+}
+
+/**
+ * The decoder plugin failed to load any tags: fall back to the APE or
+ * ID3 tag loader.
+ */
+static struct tag *
+tag_fallback(const char *path, struct tag *tag)
+{
+	struct tag *fallback = tag_load_fallback(path);
+
+	if (fallback != NULL) {
+		/* tag was successfully loaded: copy the song
+		   duration, and destroy the old (empty) tag */
+		fallback->time = tag->time;
+		tag_free(tag);
+		return fallback;
+	} else
+		/* no APE/ID3 tag found: return the empty tag */
+		return tag;
+}
+
 bool
 song_file_update(struct song *song)
 {
@@ -142,6 +175,9 @@ song_file_update(struct song *song)
 		plugin = decoder_plugin_from_suffix(suffix, true);
 	} while (plugin != NULL);
 
+	if (song->tag != NULL && tag_is_empty(song->tag))
+		song->tag = tag_fallback(path_fs, song->tag);
+
 	g_free(path_fs);
 	return song->tag != NULL;
 }