sanei_usb: Add function to check whether we are using fake data

include/sane/sanei_usb.h

@@ -219,6 +219,11 @@ extern SANE_Status sanei_usb_testing_enable_record(SANE_String_Const path,
  */
 extern SANE_String sanei_usb_testing_get_backend();
 
+/** Returns SANE_TRUE if replay testing mode is enabled, i.e. whether we are working with fake
+ * scan data.
+ */
+extern SANE_Bool sanei_usb_is_replay_mode_enabled();
+
 /** Initialize sanei_usb.
  *
  * Call this before any other sanei_usb function.

sanei/sanei_usb.c

@@ -981,6 +981,14 @@ SANE_String sanei_usb_testing_get_backend()
   return ret;
 }
 
+SANE_Bool sanei_usb_is_replay_mode_enabled()
+{
+  if (testing_mode == sanei_usb_testing_mode_replay)
+    return SANE_TRUE;
+
+  return SANE_FALSE;
+}
+
 static void sanei_usb_add_endpoint(device_list_type* device,
                                    SANE_Int transfer_type,
                                    SANE_Int ep_address,