Make the VST3 bundle detection more specific

In yabridge itself.

CHANGELOG.md

@@ -8,6 +8,14 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed a rare edge case where a Windows VST3 plugin would incorrectly be
+  classified as a bundle, causing loading the plugin to fail. This could happen
+  if the directory `foo` contained some random directory, containing another
+  directory, containing `foo.vst3`. Yabridge always assumed this to be a bundle,
+  even if it is not.
+
 ### yabridge
 
 - Don't panic when someone `yabridgectl add`'ed part of the contents of a

src/plugin/utils.cpp

@@ -239,9 +239,16 @@ fs::path normalize_plugin_path(const fs::path& windows_library_path,
             // an old standalone module
             const fs::path win_module_name =
                 windows_library_path.filename().replace_extension(".vst3");
+            // NOTE: This extra check is needed to prevent
+            //       `<plugin_dir>/foo/X/Y/foo.vst3` from being recognized as a
+            //       bundle when it isn't in fact a bundle.
+            const fs::path windows_bundle_contents =
+                windows_library_path.parent_path().parent_path();
             const fs::path windows_bundle_home =
-                windows_library_path.parent_path().parent_path().parent_path();
-            if (equals_case_insensitive(windows_bundle_home.filename().string(),
+                windows_bundle_contents.parent_path();
+            if (equals_case_insensitive(windows_bundle_contents.string(),
+                                        "Contents") &&
+                equals_case_insensitive(windows_bundle_home.filename().string(),
                                         win_module_name.string())) {
                 return windows_bundle_home;
             } else {