win-capture: Violate Vulkan spec for compatibility

Rivatuner Statistics Server calls vkGetInstanceProcAddr for
vkCreateDevice with a NULL instance. According to spec, this should
return NULL, but RTSS will dereference this and crash.

This change returns function pointers for every intercepted function
regardless of instance, which is enough to keep RTSS alive.

plugins/win-capture/graphics-hook/vulkan-capture.c

@@ -1742,21 +1742,21 @@ static void VKAPI_CALL OBS_DestroySurfaceKHR(VkInstance inst, VkSurfaceKHR surf,
 	destroy_surface(inst, surf, ac);
 }
 
-#define GETPROCADDR(func)              \
-	if (!strcmp(name, "vk" #func)) \
+#define GETPROCADDR(func)               \
+	if (!strcmp(pName, "vk" #func)) \
 		return (PFN_vkVoidFunction)&OBS_##func;
 
-#define GETPROCADDR_IF_SUPPORTED(func) \
-	if (!strcmp(name, "vk" #func)) \
+#define GETPROCADDR_IF_SUPPORTED(func)  \
+	if (!strcmp(pName, "vk" #func)) \
 		return funcs->func ? (PFN_vkVoidFunction)&OBS_##func : NULL;
 
-static PFN_vkVoidFunction VKAPI_CALL OBS_GetDeviceProcAddr(VkDevice dev,
-							   const char *name)
+static PFN_vkVoidFunction VKAPI_CALL OBS_GetDeviceProcAddr(VkDevice device,
+							   const char *pName)
 {
-	struct vk_data *data = get_device_data(dev);
+	struct vk_data *data = get_device_data(device);
 	struct vk_device_funcs *funcs = &data->funcs;
 
-	debug_procaddr("vkGetDeviceProcAddr(%p, \"%s\")", dev, name);
+	debug_procaddr("vkGetDeviceProcAddr(%p, \"%s\")", device, pName);
 
 	GETPROCADDR(GetDeviceProcAddr);
 	GETPROCADDR(DestroyDevice);
@@ -1766,24 +1766,43 @@ static PFN_vkVoidFunction VKAPI_CALL OBS_GetDeviceProcAddr(VkDevice dev,
 
 	if (funcs->GetDeviceProcAddr == NULL)
 		return NULL;
-	return funcs->GetDeviceProcAddr(dev, name);
+	return funcs->GetDeviceProcAddr(device, pName);
 }
 
-static PFN_vkVoidFunction VKAPI_CALL OBS_GetInstanceProcAddr(VkInstance inst,
-							     const char *name)
+/* bad layers require spec violation */
+#define RETURN_FP_FOR_NULL_INSTANCE 1
+
+static PFN_vkVoidFunction VKAPI_CALL
+OBS_GetInstanceProcAddr(VkInstance instance, const char *pName)
 {
-	debug_procaddr("vkGetInstanceProcAddr(%p, \"%s\")", inst, name);
+	debug_procaddr("vkGetInstanceProcAddr(%p, \"%s\")", instance, pName);
 
 	/* instance chain functions we intercept */
 	GETPROCADDR(GetInstanceProcAddr);
 	GETPROCADDR(CreateInstance);
 
-	if (inst == NULL)
+#if RETURN_FP_FOR_NULL_INSTANCE
+	/* other instance chain functions we intercept */
+	GETPROCADDR(DestroyInstance);
+	GETPROCADDR(CreateWin32SurfaceKHR);
+	GETPROCADDR(DestroySurfaceKHR);
+
+	/* device chain functions we intercept */
+	GETPROCADDR(GetDeviceProcAddr);
+	GETPROCADDR(CreateDevice);
+	GETPROCADDR(DestroyDevice);
+
+	if (instance == NULL)
+		return NULL;
+
+	struct vk_inst_funcs *const funcs = get_inst_funcs(instance);
+#else
+	if (instance == NULL)
 		return NULL;
 
-	struct vk_inst_funcs *funcs = get_inst_funcs(inst);
+	struct vk_inst_funcs *const funcs = get_inst_funcs(instance);
 
-	/* instance chain functions we intercept */
+	/* other instance chain functions we intercept */
 	GETPROCADDR(DestroyInstance);
 	GETPROCADDR_IF_SUPPORTED(CreateWin32SurfaceKHR);
 	GETPROCADDR_IF_SUPPORTED(DestroySurfaceKHR);
@@ -1792,9 +1811,10 @@ static PFN_vkVoidFunction VKAPI_CALL OBS_GetInstanceProcAddr(VkInstance inst,
 	GETPROCADDR(GetDeviceProcAddr);
 	GETPROCADDR(CreateDevice);
 	GETPROCADDR(DestroyDevice);
-	if (funcs->GetInstanceProcAddr == NULL)
-		return NULL;
-	return funcs->GetInstanceProcAddr(inst, name);
+#endif
+
+	const PFN_vkGetInstanceProcAddr gipa = funcs->GetInstanceProcAddr;
+	return gipa ? gipa(instance, pName) : NULL;
 }
 
 #undef GETPROCADDR