fix: D435 -- replugged controllers never reopened (render-thread event pump swallowed hot-plug events)

SDL_CONTROLLERDEVICEADDED / REMOVED are dequeued by whichever of the two
event pumps polls first; fast3d's gfx_sdl_handle_events had no case for
them and dropped them, so inputRescanPads never ran after a replug (the
stale handle later aborted in malloc). Both pumps now post a request and
inputUpdate() consumes it on the pad-reading thread. Findings D435.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

port/fast3d/gfx_sdl2.cpp

@@ -10,6 +10,7 @@
 #include "input.h"
 
 extern "C" void videoRequestQuit(const char *why);   // port/src/video.c (D344)
+extern "C" void inputRequestRescan(void);   // port/src/input.c (D435)
 
 static SDL_Window* wnd;
 static SDL_GLContext ctx;
@@ -339,6 +340,10 @@ static void gfx_sdl_handle_events(void) {
             case SDL_MOUSEWHEEL:
                 inputPostWheel(event.wheel.y);   // weapon cycle
                 break;
+            case SDL_CONTROLLERDEVICEADDED:     // D435: this pump and video.c's drain the same
+            case SDL_CONTROLLERDEVICEREMOVED:   // SDL queue; request a rescan, never rescan here
+                inputRequestRescan();
+                break;
             case SDL_WINDOWEVENT:
                 if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED) {
                     SDL_GL_GetDrawableSize(wnd, &window_width, &window_height);

port/include/input.h

@@ -87,6 +87,7 @@ int  inputMenuPointerLive(void);
 
 /* Re-enumerate gamepads after a hotplug (SDL_CONTROLLERDEVICEADDED/REMOVED). */
 void inputRescanPads(void);
+void inputRequestRescan(void);   /* D435: from either SDL event pump; consumed by inputUpdate() */
 
 /* D401: Rumble Pak -> real gamepad haptics. The osMotor* shims in
  * libultra.c (game's src/joy.c rumble state machine) route here.

port/src/input.c

@@ -926,8 +926,23 @@ void inputDestroy(void)
 
 /* Poll once per controller-read: refresh SDL device state and integrate the
  * mouse-aim delta into the accumulator. */
+/* D435: controller hot-plug. SDL_CONTROLLERDEVICEADDED / REMOVED land on
+ * whichever of the two event pumps dequeues them first: video.c's host loop
+ * or fast3d's gfx_sdl_handle_events (render thread, every frame), and the
+ * latter used to drop them, so a replugged pad was never reopened. Both pumps
+ * now only post a request; the rescan runs here, at the top of inputUpdate(),
+ * on the thread that is about to read pads[], so a pad is never closed under
+ * a reader. */
+static SDL_atomic_t s_rescanReq;
+
+void inputRequestRescan(void)
+{
+    SDL_AtomicSet(&s_rescanReq, 1);
+}
+
 void inputUpdate(void)
 {
+    if (SDL_AtomicSet(&s_rescanReq, 0)) inputRescanPads();   /* D435 */
     SDL_GameControllerUpdate();
 
     /* D287: skip until the host thread has actually enabled relative mode

port/src/video.c

@@ -865,7 +865,7 @@ void videoPumpEvents(void)
             break;
         case SDL_CONTROLLERDEVICEADDED:
         case SDL_CONTROLLERDEVICEREMOVED:
-            inputRescanPads();
+            inputRequestRescan();   /* D435: the rescan runs on the pad-reading thread */
             break;
         case SDL_WINDOWEVENT:
             if (ev.window.event == SDL_WINDOWEVENT_CLOSE) {