medialib: fix numeric sorting by track number (fixes #3287)

Author: Oleksiy-Yakovenko

include/deadbeef/deadbeef.h

@@ -754,6 +754,9 @@ typedef enum {
     // Allow faster metadata lookups, but without "override" support.
     // This is mostly suitable for medialib tree formatting.
     DDB_TF_CONTEXT_FAST_LOOKUP = 64,
+
+    // Force track numbers to have more zero padding, to make sense when sorting
+    DDB_TF_FORCE_SORTABLE_TRACK_NUMBER = 128,
 #endif
 } ddb_tf_flags_t;
 

plugins/medialib/medialibtree.c

@@ -241,7 +241,7 @@ _create_tf_tree(medialib_source_t *source, ml_tree_item_t *root, int selected, c
     if (needs_sort) {
         ddb_tf_context_t ctx = {
             ._size = sizeof (ddb_tf_context_t),
-            .flags = DDB_TF_CONTEXT_NO_DYNAMIC | DDB_TF_CONTEXT_NO_MUTEX_LOCK | DDB_TF_CONTEXT_FAST_LOOKUP,
+            .flags = DDB_TF_CONTEXT_NO_DYNAMIC | DDB_TF_CONTEXT_NO_MUTEX_LOCK | DDB_TF_CONTEXT_FAST_LOOKUP | DDB_TF_FORCE_SORTABLE_TRACK_NUMBER,
             .plt = source->ml_playlist,
             .idx = -1,
         };
@@ -468,8 +468,19 @@ _create_sorted_folder_tree(ddb_playlist_t *plt, ml_tree_item_t *parent, int sele
 static void
 _create_folder_tree(medialib_source_t *source, ml_tree_item_t *root, const char *track_tf, int selected, int needs_sort) {
     if (needs_sort) {
-        const char *sort_tf = "$directory_path(%path%)/[%album artist% - ]%album%/[%tracknumber%. ]%title%";
-        deadbeef->plt_sort_v2(source->ml_playlist, PL_MAIN, -1, sort_tf, DDB_SORT_ASCENDING);
+        ddb_tf_context_t ctx = {
+            ._size = sizeof (ddb_tf_context_t),
+            .flags = DDB_TF_CONTEXT_NO_DYNAMIC | DDB_TF_CONTEXT_NO_MUTEX_LOCK | DDB_TF_CONTEXT_FAST_LOOKUP | DDB_TF_FORCE_SORTABLE_TRACK_NUMBER,
+            .plt = source->ml_playlist,
+            .idx = -1,
+        };
+
+        const char *tf_sort = "$directory_path(%path%)/[%album artist% - ]%album%/[%tracknumber%. ]%title%";
+        char *tf_bytecode = deadbeef->tf_compile(tf_sort);
+
+        deadbeef->plt_sort_v3(&ctx, tf_bytecode, PL_MAIN, -1, DDB_SORT_ASCENDING);
+
+        deadbeef->tf_free(tf_bytecode);
     }
 
     char *track_tf_bc = deadbeef->tf_compile(track_tf);

src/tf.c

@@ -2972,20 +2972,27 @@ _get_title_from_path(const char *path, const char **end) {
 }
 
 static int
-_get_tracknumber_from_string(const char *v, char *out, int outlen) {
+_get_tracknumber_from_string(const char *v, char *out, int outlen, int force_sortable) {
     const char *p = v;
+
     while (*p) {
         if (!isdigit (*p)) {
             break;
         }
         p++;
     }
-    if (p > v && *p == 0 && p-v == 1) {
-        return snprintf_clip (out, outlen, "%02d", atoi(v));
-    }
-    else {
-        return -1;
+
+    if (p > v && *p == 0 ) {
+        if (force_sortable) {
+            return snprintf_clip (out, outlen, "%05d", atoi(v));
+        }
+
+        if (p - v == 1) {
+            return snprintf_clip (out, outlen, "%02d", atoi(v));
+        }
     }
+
+    return -1;
 }
 
 /*
@@ -3122,7 +3129,7 @@ tf_eval_int (ddb_tf_context_t *ctx, const char *code, int size, char *out, int o
                 else if (!strcmp (name, "tracknumber")) {
                     const char *v = pl_find_meta_raw (it, "track");
                     if (v) {
-                        int l = _get_tracknumber_from_string(v, out, outlen);
+                        int l = _get_tracknumber_from_string(v, out, outlen, (ctx->flags & DDB_TF_FORCE_SORTABLE_TRACK_NUMBER) != 0);
                         if (l >= 0) {
                             out += l;
                             outlen -= l;
@@ -3824,7 +3831,7 @@ tf_eval_int (ddb_tf_context_t *ctx, const char *code, int size, char *out, int o
                             v = meta->value;
                         }
                         if (v) {
-                            int l = _get_tracknumber_from_string(v, out, outlen);
+                            int l = _get_tracknumber_from_string(v, out, outlen, (ctx->flags & DDB_TF_FORCE_SORTABLE_TRACK_NUMBER) != 0);
                             if (l >= 0) {
                                 out += l;
                                 outlen -= l;