fpi: Add paddings to the private structs

libfprint/fpi-assembling.h

@@ -110,6 +110,7 @@ struct fpi_line_asmbl_ctx
   unsigned char (*get_pixel)(struct fpi_line_asmbl_ctx *ctx,
                              GSList                    *line,
                              unsigned int               x);
+  gpointer _padding_dummy[32];
 };
 
 FpImage *fpi_assemble_lines (struct fpi_line_asmbl_ctx *ctx,

libfprint/fpi-device.h

@@ -45,6 +45,10 @@ struct _FpIdEntry
     const gchar *virtual_envvar;
   };
   guint64 driver_data;
+
+  /*< private >*/
+  /* padding for future expansion */
+  gpointer _padding_dummy[16];
 };
 
 /**
@@ -129,6 +133,10 @@ struct _FpDeviceClass
   void (*delete)   (FpDevice * device);
 
   void (*cancel)   (FpDevice *device);
+
+  /*< private >*/
+  /* padding for future expansion */
+  gpointer _padding_dummy[32];
 };
 
 /**

libfprint/fpi-image-device.h

@@ -93,6 +93,10 @@ struct _FpImageDeviceClass
   void          (*change_state) (FpImageDevice      *dev,
                                  FpiImageDeviceState state);
   void          (*deactivate)   (FpImageDevice *dev);
+
+  /*< private >*/
+  /* padding for future expansion */
+  gpointer _padding_dummy[32];
 };
 
 void fpi_image_device_set_bz3_threshold (FpImageDevice *self,

libfprint/fpi-usb-transfer.h

@@ -101,6 +101,10 @@ struct _FpiUsbTransfer
 
   /* Data free function */
   GDestroyNotify free_buffer;
+
+  /*< private >*/
+  /* padding for future expansion */
+  gpointer _padding_dummy[32];
 };
 
 GType              fpi_usb_transfer_get_type (void) G_GNUC_CONST;