Only process surface configure if size has changed

[gartnera]

I'm not sure why we're getting multiple layer_surface_configure callbacks in the first place, but this change ensures that we only respond to them if the surface size has actually changed.

This seems to fix #223 but I'm not exactly sure why.

I would also add this logic to ext_session_lock_surface_v1_handle_configure but I couldn't figure out how to get that protocol enabled for testing.

Before:

➜  swaylock-dpms-git git:(master) ✗ ninja -C build && ./build/swaylock --indicator-idle-visible
ninja: Entering directory `build'
[2/2] Linking target swaylock
layer_surface_configure: 22600, 1706, 960
layer_surface_configure done: 22600
layer_surface_configure: 22602, 1706, 960
layer_surface_configure done: 22602
layer_surface_configure: 22604, 1706, 960
layer_surface_configure done: 22604
layer_surface_configure: 22606, 1706, 960
layer_surface_configure done: 22606
layer_surface_configure: 22608, 1706, 960
layer_surface_configure done: 22608
layer_surface_configure: 22613, 1706, 960
layer_surface_configure done: 22613
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done

After:

➜  swaylock-dpms-git git:(master) ✗ ninja -C build && ./build/swaylock --indicator-idle-visible -s solid_color
ninja: Entering directory `build'
[2/2] Linking target swaylock
layer_surface_configure: 23098, 1706, 960
layer_surface_configure done: 23098
layer_surface_configure: 23100, 1706, 960
layer_surface_configure: 23102, 1706, 960
layer_surface_configure done: 23102
layer_surface_configure: 23104, 1706, 960
layer_surface_configure: 23106, 1706, 960
layer_surface_configure: 23111, 1706, 960
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done
surface_handle_frame_done

[primalmotion]

I confirm that this patch fixes the flicker for me

[emersion]

This is incorrect, we always need to ack_configure even if the size didn't change per the protocol spec.

[gartnera]

This is incorrect, we always need to ack_configure even if the size didn't change per the protocol spec.

Sorry, I'm not exactly sure what I'm doing. This excerpt from the zwlr_layer_surface_v1_ack_configure doc string seemed to indicate that we didn't have to ack unless we actually do something:

When a configure event is received, if a client commits the
surface in response to the configure event, then the client
must make an ack_configure request sometime before the commit
request, passing along the serial of the configure event.

[primalmotion]

without this patch, swaylock just hangs after the circle hiccup now in master for me.