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

android-project/jni/Android.mk

@@ -0,0 +1 @@
+include $(call all-subdir-makefiles)

android-project/jni/Application.mk

@@ -0,0 +1,6 @@
+
+# Uncomment this if you're using STL in your project
+# See CPLUSPLUS-SUPPORT.html in the NDK documentation for more information
+# APP_STL := stlport_static 
+
+APP_ABI := armeabi armeabi-v7a x86

android-project/jni/src/Android.mk

@@ -0,0 +1,19 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := main
+
+SDL_PATH := ../SDL
+
+LOCAL_C_INCLUDES := $(LOCAL_PATH)/$(SDL_PATH)/include
+
+# Add your application source files here...
+LOCAL_SRC_FILES := $(SDL_PATH)/src/main/android/SDL_android_main.c \
+	YourSourceHere.c
+
+LOCAL_SHARED_LIBRARIES := SDL2
+
+LOCAL_LDLIBS := -lGLESv1_CM -lGLESv2 -llog
+
+include $(BUILD_SHARED_LIBRARY)

android-project/jni/src/Android_static.mk

@@ -0,0 +1,12 @@
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := main
+
+LOCAL_SRC_FILES := YourSourceHere.c
+
+LOCAL_STATIC_LIBRARIES := SDL2_static
+
+include $(BUILD_SHARED_LIBRARY)
+$(call import-module,SDL)LOCAL_PATH := $(call my-dir)