the last parameter of XChangeProperty is the number of elements.. and when the element format is 32.. the element is "long" so we have 5 long elements here.

Yes this seems confusing as on mac+linux Long is either 32 or 64bits depending on the architecture, but this is how the X11 protocol is defined. Thus 5 is the correct value for the nelts here.  Not 5 or 10 depending on the architecture.

More info on the confusion https://bugs.freedesktop.org/show_bug.cgi?id=16802

visualtest/configs/testsprite2_geometry/testsprite2_geometry.actions

@@ -0,0 +1,3 @@
+00:00:03 SCREENSHOT
+00:00:06 VERIFY
+00:00:09 QUIT

visualtest/configs/testsprite2_geometry/testsprite2_geometry.config

@@ -0,0 +1,5 @@
+parameter-config=testsprite2_geometry.parameters
+variator=exhaustive
+sutapp=testsprite2
+timeout=00:00:15
+action-config=testsprite2_geometry.actions

visualtest/configs/testsprite2_geometry/testsprite2_geometry.parameters

@@ -0,0 +1,5 @@
+# parameter name, type, value range, required, categories
+--geometry, enum, [500x500 600x600], false, []
+--logical, enum, [300x500 550x450], false, []
+--scale, integer, [1 5], false, []
+--iterations, integer, [1000 1000], true, []