Redundantly limit number of drag-and-drop formats

As reported in #149, the DrumCore 3 plugin would segfault when trying to
drag files from it. This happened because the plugin presumably
underflows somewhere and then reports that it supports 4294967282
different drag-and-drop formats, even though yabridge asked for a
maximum of 16.

CHANGELOG.md

@@ -20,6 +20,10 @@ Versioning](https://semver.org/spec/v2.0.0.html).
   when the GUI changes. Yabridge now detects this, and removes the throttling we
   have in place to prevent certain other plugins from getting stuck in infinite
   loops.
+- Fixed **DrumCore 3** crashing when trying to drag grooves from the plugin to
+  other applications. This happened because of an integer underflow in that
+  plugin, causing the number of reported drag-and-drop formats to be magnitudes
+  higher than yabridge's indicated maximum.
 - Fixed Wine version detection in the build configuration.
 
 ## [3.7.0] - 2021-11-21

src/wine-host/xdnd-proxy.cpp

@@ -790,6 +790,11 @@ void CALLBACK dnd_winevent_callback(HWINEVENTHOOK /*hWinEventHook*/,
                      &num_formats);
     enumerator->Release();
 
+    // NOTE: This DrumCore 3 plugin reports 4294967282 for `num_formats` which
+    //       is uh a lot more than 16. So to prevent causing a segfault here we
+    //       need to manually cap `num_formats` to 16.
+    num_formats = std::min(num_formats, static_cast<unsigned int>(16));
+
     // NOTE: MeldaProduction plugins don't return any supported formats for some
     //       reason, so we'll hardcode a HDROP
     if (num_formats == 0) {