musicbrainz: do not append all tags by default

The way the awful credits musicbrainz API works is that you need
to append each credit with a joiner string. The common macro
we used to do that did this for all strings. Which worked, as
long as the metadata field was completely empty. Which got changed.

So, instead of always appending, just append where we need to.

Author: cyanreg

src/musicbrainz.c

@@ -22,8 +22,9 @@
 #include <musicbrainz5/mb5_c.h>
 #include <libavutil/crc.h>
 
-#define READ_MB(FUNC, MBCTX, DICT, KEY)                                             \
+#define READ_MB(FUNC, MBCTX, DICT, KEY, APPEND)                                     \
     do {                                                                            \
+        int flags = AV_DICT_DONT_STRDUP_VAL | ((APPEND) ? AV_DICT_APPEND : 0x0);    \
         if (!MBCTX)                                                                 \
             break;                                                                  \
         int len = FUNC(MBCTX, NULL, 0) + 1;                                         \
@@ -32,24 +33,26 @@
         if (str[0] == '\0')                                                         \
             av_free(str);                                                           \
         else                                                                        \
-            av_dict_set(&DICT, KEY, str, AV_DICT_DONT_STRDUP_VAL | AV_DICT_APPEND); \
+            av_dict_set(&DICT, KEY, str, flags);                                    \
     } while (0)
 
 static void mb_credit(Mb5ArtistCredit credit, AVDictionary *dict, const char *key)
 {
+    int append = 0;
     Mb5NameCreditList namecredit_list = mb5_artistcredit_get_namecreditlist(credit);
+
     for (int i = 0; i < mb5_namecredit_list_size(namecredit_list); i++) {
         Mb5NameCredit namecredit = mb5_namecredit_list_item(namecredit_list, i);
 
         if (mb5_namecredit_get_name(namecredit, NULL, 0)) {
-            READ_MB(mb5_namecredit_get_name, namecredit, dict, key);
+            READ_MB(mb5_namecredit_get_name, namecredit, dict, key, append++);
         } else {
             Mb5Artist artist = mb5_namecredit_get_artist(namecredit);
             if (artist)
-                READ_MB(mb5_artist_get_name, artist, dict, key);
+                READ_MB(mb5_artist_get_name, artist, dict, key, append++);
         }
 
-        READ_MB(mb5_namecredit_get_joinphrase, namecredit, dict, key);
+        READ_MB(mb5_namecredit_get_joinphrase, namecredit, dict, key, append++);
     }
 }
 
@@ -68,14 +71,14 @@ static uint32_t crc_medium(Mb5Medium medium)
         Mb5Track track = mb5_track_list_item(track_list, i);
         Mb5Recording recording = mb5_track_get_recording(track);
 
-        READ_MB(mb5_recording_get_id, recording, tmp_dict, "mbid");
+        READ_MB(mb5_recording_get_id, recording, tmp_dict, "mbid", 0);
 
         Mb5ArtistCredit credit;
         if (recording) {
-            READ_MB(mb5_recording_get_title, recording, tmp_dict, "title");
+            READ_MB(mb5_recording_get_title, recording, tmp_dict, "title", 0);
             credit = mb5_recording_get_artistcredit(recording);
         } else {
-            READ_MB(mb5_track_get_title, track, tmp_dict, "title");
+            READ_MB(mb5_track_get_title, track, tmp_dict, "title", 0);
             credit = mb5_track_get_artistcredit(track);
         }
         if (credit)
@@ -144,8 +147,8 @@ static int mb_tracks(cyanrip_ctx *ctx, Mb5Release release, const char *discid, i
         }
     }
 
-    READ_MB(mb5_medium_get_title, medium, ctx->meta, "discname");
-    READ_MB(mb5_medium_get_format, medium, ctx->meta, "format");
+    READ_MB(mb5_medium_get_title, medium, ctx->meta, "discname", 0);
+    READ_MB(mb5_medium_get_format, medium, ctx->meta, "format", 0);
 
     Mb5TrackList track_list = mb5_medium_get_tracklist(medium);
     if (!track_list) {
@@ -161,14 +164,14 @@ static int mb_tracks(cyanrip_ctx *ctx, Mb5Release release, const char *discid, i
         Mb5Track track = mb5_track_list_item(track_list, i);
         Mb5Recording recording = mb5_track_get_recording(track);
 
-        READ_MB(mb5_recording_get_id, recording, ctx->tracks[i].meta, "mbid");
+        READ_MB(mb5_recording_get_id, recording, ctx->tracks[i].meta, "mbid", 0);
 
         Mb5ArtistCredit credit;
         if (recording) {
-            READ_MB(mb5_recording_get_title, recording, ctx->tracks[i].meta, "title");
+            READ_MB(mb5_recording_get_title, recording, ctx->tracks[i].meta, "title", 0);
             credit = mb5_recording_get_artistcredit(recording);
         } else {
-            READ_MB(mb5_track_get_title, track, ctx->tracks[i].meta, "title");
+            READ_MB(mb5_track_get_title, track, ctx->tracks[i].meta, "title", 0);
             credit = mb5_track_get_artistcredit(track);
         }
         if (credit)
@@ -266,11 +269,11 @@ static int mb_metadata(cyanrip_ctx *ctx, int manual_metadata_specified, int rele
         for (int i = 0; i < num_releases; i++) {
             release = mb5_release_list_item(release_list, i);
             AVDictionary *tmp_dict = NULL;
-            READ_MB(mb5_release_get_date, release, tmp_dict, "date");
-            READ_MB(mb5_release_get_title, release, tmp_dict, "album");
-            READ_MB(mb5_release_get_id, release, tmp_dict, "id");
-            READ_MB(mb5_release_get_disambiguation, release, tmp_dict, "disambiguation");
-            READ_MB(mb5_release_get_country, release, tmp_dict, "country");
+            READ_MB(mb5_release_get_date, release, tmp_dict, "date", 0);
+            READ_MB(mb5_release_get_title, release, tmp_dict, "album", 0);
+            READ_MB(mb5_release_get_id, release, tmp_dict, "id", 0);
+            READ_MB(mb5_release_get_disambiguation, release, tmp_dict, "disambiguation", 0);
+            READ_MB(mb5_release_get_country, release, tmp_dict, "country", 0);
 
             Mb5MediumList medium_list = mb5_release_get_mediumlist(release);
             int num_cds = mb5_medium_list_size(medium_list);
@@ -312,7 +315,7 @@ static int mb_metadata(cyanrip_ctx *ctx, int manual_metadata_specified, int rele
         for (; i < num_releases; i++) {
             release = mb5_release_list_item(release_list, i);
             AVDictionary *tmp_dict = NULL;
-            READ_MB(mb5_release_get_id, release, tmp_dict, "id");
+            READ_MB(mb5_release_get_id, release, tmp_dict, "id", 0);
             if (dict_get(tmp_dict, "id") && !strcmp(release_str, dict_get(tmp_dict, "id"))) {
                 av_dict_free(&tmp_dict);
                 break;
@@ -328,23 +331,23 @@ static int mb_metadata(cyanrip_ctx *ctx, int manual_metadata_specified, int rele
         release = mb5_release_list_item(release_list, 0);
     }
 
-    READ_MB(mb5_release_get_id, release, ctx->meta, "release_id");
-    READ_MB(mb5_release_get_disambiguation, release, ctx->meta, "releasecomment");
-    READ_MB(mb5_release_get_date, release, ctx->meta, "date");
-    READ_MB(mb5_release_get_title, release, ctx->meta, "album");
-    READ_MB(mb5_release_get_barcode, release, ctx->meta, "barcode");
-    READ_MB(mb5_release_get_packaging, release, ctx->meta, "packaging");
-    READ_MB(mb5_release_get_country, release, ctx->meta, "country");
-    READ_MB(mb5_release_get_status, release, ctx->meta, "status");
+    READ_MB(mb5_release_get_id, release, ctx->meta, "release_id", 0);
+    READ_MB(mb5_release_get_disambiguation, release, ctx->meta, "releasecomment", 0);
+    READ_MB(mb5_release_get_date, release, ctx->meta, "date", 0);
+    READ_MB(mb5_release_get_title, release, ctx->meta, "album", 0);
+    READ_MB(mb5_release_get_barcode, release, ctx->meta, "barcode", 0);
+    READ_MB(mb5_release_get_packaging, release, ctx->meta, "packaging", 0);
+    READ_MB(mb5_release_get_country, release, ctx->meta, "country", 0);
+    READ_MB(mb5_release_get_status, release, ctx->meta, "status", 0);
 
     /* Label info */
     Mb5LabelInfoList *labelinfolist = mb5_release_get_labelinfolist(release);
     if (mb5_labelinfo_list_size(labelinfolist) == 1) {
         Mb5LabelInfo *labelinfo = mb5_label_list_item(labelinfolist, 0);
-        READ_MB(mb5_labelinfo_get_catalognumber, labelinfo, ctx->meta, "catalog");
+        READ_MB(mb5_labelinfo_get_catalognumber, labelinfo, ctx->meta, "catalog", 0);
 
         Mb5Label *label = mb5_labelinfo_get_label(labelinfo);
-        READ_MB(mb5_label_get_name, label, ctx->meta, "label");
+        READ_MB(mb5_label_get_name, label, ctx->meta, "label", 0);
     }
 
     Mb5ArtistCredit artistcredit = mb5_release_get_artistcredit(release);