Flexible thumbnail matching

Add logic to handle 3 possible thumbnail names, in following order:
- most exact name derived from content file (same name, with .png extension)
- usual name derived from playlist (usually coming from database)
- shortened name, chopping off region/publisher etc. info

gfx/gfx_thumbnail_path.c

@@ -37,14 +37,23 @@
 
 /* Fills content_img field of path_data using existing
  * content_label field (for internal use only) */
-static void gfx_thumbnail_fill_content_img(char *s, size_t len, const char *src)
+static void gfx_thumbnail_fill_content_img(char *s, size_t len, const char *src, bool shorten)
 {
+   const char* cut = " (";
    char *scrub_char_ptr = NULL;
    /* Copy source label string */
    size_t _len          = strlcpy(s, src, len);
+   size_t shortlen;
+
+   /* Shortening logic: up to first space + bracket */
+   if (shorten) {
+      shortlen = string_find_index_substring_string(src, cut);
+      if (shortlen > 3)
+         _len = shortlen;
+   }
    /* Scrub characters that are not cross-platform and/or violate the
     * No-Intro filename standard:
-    * http://datomatic.no-intro.org/stuff/The%20Official%20No-Intro%20Convention%20(20071030).zip
+    * https://datomatic.no-intro.org/stuff/The%20Official%20No-Intro%20Convention%20(20071030).pdf
     * Replace these characters in the entry name with underscores */
    while ((scrub_char_ptr = strpbrk(s, "&*/:`\"<>?\\|")))
       *scrub_char_ptr = '_';
@@ -289,7 +298,9 @@ bool gfx_thumbnail_set_content(gfx_thumbnail_path_data_t *path_data, const char
 
    /* Determine content image name */
    gfx_thumbnail_fill_content_img(path_data->content_img,
-         sizeof(path_data->content_img), path_data->content_label);
+         sizeof(path_data->content_img), path_data->content_label, false);
+   gfx_thumbnail_fill_content_img(path_data->content_img_short,
+         sizeof(path_data->content_img_short), path_data->content_label, true);
 
    /* Have to set content path to *something*...
     * Just use label value (it doesn't matter) */
@@ -444,8 +455,6 @@ bool gfx_thumbnail_set_content_playlist(
             "", sizeof(path_data->content_label));
 
    /* Determine content image name */
-   if (settings->bools.playlist_use_filename ||
-       playlist_thumbnail_match_with_filename(playlist))
    {
       char* content_name_no_ext = NULL;
       char tmp_buf[PATH_MAX_LENGTH];
@@ -457,13 +466,13 @@ bool gfx_thumbnail_set_content_playlist(
       strlcpy(tmp_buf, base_name, sizeof(tmp_buf));
       content_name_no_ext = path_remove_extension(tmp_buf);
 
+      gfx_thumbnail_fill_content_img(path_data->content_img_full,
+         sizeof(path_data->content_img_full), content_name_no_ext,false);
       gfx_thumbnail_fill_content_img(path_data->content_img,
-         sizeof(path_data->content_img), content_name_no_ext);
-   }
-   else
-   {
-      gfx_thumbnail_fill_content_img(path_data->content_img,
-         sizeof(path_data->content_img), path_data->content_label);
+         sizeof(path_data->content_img), path_data->content_label,false);
+
+      gfx_thumbnail_fill_content_img(path_data->content_img_short,
+         sizeof(path_data->content_img_short), path_data->content_label,true);
    }
 
    /* Store playlist index */
@@ -620,10 +629,28 @@ bool gfx_thumbnail_update_path(
       /* >> Add type */
       fill_pathname_join_special(tmp_buf, thumbnail_path, type, sizeof(tmp_buf));
 
-      /* >> Add content image */
       thumbnail_path[0] = '\0';
-      fill_pathname_join_special(thumbnail_path, tmp_buf,
-            path_data->content_img, PATH_MAX_LENGTH * sizeof(char));
+      /* >> Add content image - first try with full file name */
+      if(path_data->content_img_full[0] != '\0') {
+         fill_pathname_join_special(thumbnail_path, tmp_buf,
+               path_data->content_img_full, PATH_MAX_LENGTH * sizeof(char));
+      }
+      /* >> Add content image - second try with label (database name) */
+      if(!path_is_valid(thumbnail_path) && path_data->content_img[0] != '\0')
+      {
+         thumbnail_path[0] = '\0';
+         fill_pathname_join_special(thumbnail_path, tmp_buf,
+               path_data->content_img, PATH_MAX_LENGTH * sizeof(char));
+      }
+      /* >> Add content image - third try with shortened name (title only) */
+      if(!path_is_valid(thumbnail_path) && path_data->content_img_short[0] != '\0')
+      {
+         thumbnail_path[0] = '\0';
+         fill_pathname_join_special(thumbnail_path, tmp_buf,
+               path_data->content_img_short, PATH_MAX_LENGTH * sizeof(char));
+      }
+      /* This logic is valid for locally stored thumbnails. For optional downloads, 
+       * gfx_thumbnail_get_img_name() is used which only supports the default content_img */
    }
 
    /* Final error check - is cached path empty? */

gfx/gfx_thumbnail_path.h

@@ -60,6 +60,8 @@ struct gfx_thumbnail_path_data
    size_t playlist_index;
    char content_path[PATH_MAX_LENGTH];
    char content_img[PATH_MAX_LENGTH];
+   char content_img_short[PATH_MAX_LENGTH];
+   char content_img_full[PATH_MAX_LENGTH];
    char right_path[PATH_MAX_LENGTH];
    char left_path[PATH_MAX_LENGTH];
    char content_label[256];