Work around static initialization bug in WIne 7.21

As reported here: https://bugs.winehq.org/show_bug.cgi?id=53912

CHANGELOG.md

@@ -8,6 +8,12 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
+# Fixed
+
+- Added a temporary workaround for yabridge hanging indefinitely on startup as
+  the result of a new bug in Wine 7.21:
+  https://bugs.winehq.org/show_bug.cgi?id=53912
+
 # yabridgectl
 
 - Fixed converted VST 3.7.5 `moduleinfo.json` files being considered orphan

src/wine-host/editor.cpp

@@ -117,7 +117,23 @@ constexpr uint32_t xembed_focus_in_msg = 4;
 
 constexpr uint32_t xembed_focus_first = 1;
 
-static const HCURSOR arrow_cursor = LoadCursor(nullptr, IDC_ARROW);
+/**
+ * The default arrow cursor used in Windows.
+ *
+ * FIXME: This used to be loaded as a constant, but Wine 7.21 caused this static
+ *        initialization to hang indefinitely:
+ *        https://bugs.winehq.org/show_bug.cgi?id=53912
+ *        Revert this once Wine 7.21 is old enough that noone uses it anymore.
+ */
+// static const HCURSOR arrow_cursor = LoadCursor(nullptr, IDC_ARROW);
+inline HCURSOR arrow_cursor() {
+    static HCURSOR cursor{};
+    if (!cursor) {
+        cursor = LoadCursor(nullptr, IDC_ARROW);
+    }
+
+    return cursor;
+}
 
 /**
  * Find the the ancestors for the given window. This returns a list of window
@@ -1225,7 +1241,7 @@ LRESULT CALLBACK window_proc(HWND handle,
         //       plugin and keep this as a default.
         case WM_SETCURSOR: {
             if (GetCursor() == nullptr) {
-                SetCursor(arrow_cursor);
+                SetCursor(arrow_cursor());
             }
         } break;
         // NOTE: Needed for our `is_cursor_in_wine_window()` implementation. Our
@@ -1395,7 +1411,7 @@ ATOM get_window_class() noexcept {
         window_class.style = CS_DBLCLKS;
         window_class.lpfnWndProc = window_proc;
         window_class.hInstance = GetModuleHandle(nullptr);
-        window_class.hCursor = arrow_cursor;
+        window_class.hCursor = arrow_cursor();
         window_class.lpszClassName = yabridge_window_class_name;
 
         window_class_handle = RegisterClassEx(&window_class);

src/wine-host/xdnd-proxy.cpp

@@ -53,8 +53,28 @@ constexpr char mime_text_uri_list_name[] = "text/uri-list";
 constexpr char mime_text_plain_name[] = "text/plain";
 
 // We can cheat by just using the Win32 cursors instead of providing our own
-static const HCURSOR dnd_accepted_cursor = LoadCursor(nullptr, IDC_HAND);
+// FIXME: these used to be loaded as a constant, but Wine 7.21 caused this
-static const HCURSOR dnd_denied_cursor = LoadCursor(nullptr, IDC_NO);
+//        static initialization to hang indefinitely:
+//        https://bugs.winehq.org/show_bug.cgi?id=53912
+//        Revert this once Wine 7.21 is old enough that noone uses it anymore.
+// static const HCURSOR dnd_accepted_cursor = LoadCursor(nullptr, IDC_HAND);
+inline HCURSOR dnd_accepted_cursor() {
+    static HCURSOR cursor{};
+    if (!cursor) {
+        cursor = LoadCursor(nullptr, IDC_HAND);
+    }
+
+    return cursor;
+}
+// static const HCURSOR dnd_denied_cursor = LoadCursor(nullptr, IDC_NO);
+inline HCURSOR dnd_denied_cursor() {
+    static HCURSOR cursor{};
+    if (!cursor) {
+        cursor = LoadCursor(nullptr, IDC_NO);
+    }
+
+    return cursor;
+}
 
 /**
  * We're doing a bit of a hybrid between a COM-style reference counted smart
@@ -337,9 +357,9 @@ void WineXdndProxy::run_xdnd_loop() {
             //      off. Would it be better to just not do anything
             //      at all here?
             if (accepts_drop) {
-                SetCursor(dnd_accepted_cursor);
+                SetCursor(dnd_accepted_cursor());
             } else {
-                SetCursor(dnd_denied_cursor);
+                SetCursor(dnd_denied_cursor());
             }
 
             last_window_accepted_status = accepts_drop;