CDImageCue: Try for a file based on the cue filename if bin missing

Should work around people who have renamed the files but not updated the
cuesheet.

src/common/cd_image_cue.cpp

@@ -94,8 +94,21 @@ bool CDImageCueSheet::OpenAndParse(const char* filename)
     }
     if (track_file_index == m_files.size())
     {
-      std::string track_full_filename = basepath + track_filename;
+      const std::string track_full_filename(basepath + track_filename);
       std::FILE* track_fp = FileSystem::OpenCFile(track_full_filename.c_str(), "rb");
+      if (!track_fp && track_file_index == 0)
+      {
+        // many users have bad cuesheets, or they're renamed the files without updating the cuesheet.
+        // so, try searching for a bin with the same name as the cue, but only for the first referenced file.
+        const std::string alternative_filename(FileSystem::ReplaceExtension(filename, "bin"));
+        track_fp = FileSystem::OpenCFile(alternative_filename.c_str(), "rb");
+        if (track_fp)
+        {
+          Log_WarningPrintf("Your cue sheet references an invalid file '%s', but this was found at '%s' instead.",
+                            track_filename.c_str(), alternative_filename.c_str());
+        }
+      }
+
       if (!track_fp)
       {
         Log_ErrorPrintf("Failed to open track filename '%s' (from '%s' and '%s'): errno %d",