Fix to use CMake source tree when retrieving Urho3D version number.

CMakeLists.txt

@@ -96,7 +96,7 @@ set (CPACK_PACKAGE_DESCRIPTION_SUMMARY ${URHO3D_DESCRIPTION})
 set (URHO3D_URL "https://github.com/urho3d/Urho3D")
 set (CPACK_PACKAGE_VENDOR ${URHO3D_URL})
 set (CPACK_PACKAGE_CONTACT ${URHO3D_URL})
-execute_process (COMMAND ${CMAKE_COMMAND} -P ${PROJECT_SOURCE_DIR}/CMake/Modules/GetUrho3DRevision.cmake OUTPUT_VARIABLE URHO3D_VERSION OUTPUT_STRIP_TRAILING_WHITESPACE)
+execute_process (COMMAND ${CMAKE_COMMAND} -P ${CMAKE_SOURCE_DIR}/CMake/Modules/GetUrho3DRevision.cmake WORKING_DIRECTORY ${CMAKE_SOURCE_DIR} OUTPUT_VARIABLE URHO3D_VERSION OUTPUT_STRIP_TRAILING_WHITESPACE)
 set (CPACK_PACKAGE_VERSION ${URHO3D_VERSION})
 string (REGEX MATCH "([^.]+)\\.([^.]+)\\.(.+)" MATCHED ${URHO3D_VERSION})
 if (MATCHED)

Source/Urho3D/CMakeLists.txt

@@ -30,8 +30,8 @@ endif ()
 # Define generated source files
 add_custom_command (OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/librevision.h
     COMMAND ${CMAKE_COMMAND} -DFILENAME=${CMAKE_CURRENT_BINARY_DIR}/librevision.h -P CMake/Modules/GetUrho3DRevision.cmake
-    DEPENDS ${STATIC_LIBRARY_TARGETS} ${PROJECT_SOURCE_DIR}/CMake/Modules/GetUrho3DRevision.cmake
-    WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
+    DEPENDS ${STATIC_LIBRARY_TARGETS} ${CMAKE_SOURCE_DIR}/CMake/Modules/GetUrho3DRevision.cmake
+    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
     COMMENT "Generating GIT revision number (tag + last commit SHA-1)")
 
 # Define generated object files