Make this be consistent with non-CMake builds

CMakeLists.txt

@@ -98,10 +98,10 @@ add_subdirectory(assets)
 ## config.h generation
 set(GIT_EXECUTABLE "git" CACHE FILEPATH "Path to git binary")
 include(GitUtilities)
-git_describe(SRB2_GIT_DESCRIBE "${CMAKE_SOURCE_DIR}")
+git_latest_commit(SRB2_COMP_COMMIT "${CMAKE_SOURCE_DIR}")
 git_current_branch(SRB2_GIT_BRANCH "${CMAKE_SOURCE_DIR}")
 set(SRB2_COMP_BRANCH "${SRB2_GIT_BRANCH}")
-set(SRB2_COMP_REVISION "${SRB2_GIT_DESCRIBE}")
+set(SRB2_COMP_REVISION "${SRB2_COMP_COMMIT}")
 configure_file(${CMAKE_CURRENT_SOURCE_DIR}/src/config.h.in ${CMAKE_CURRENT_BINARY_DIR}/src/config.h)
 
 ##### PACKAGE CONFIGURATION #####

cmake/Modules/GitUtilities.cmake

@@ -27,5 +27,17 @@ function(git_current_branch variable path)
 		OUTPUT_STRIP_TRAILING_WHITESPACE
 	)
 
+	set(${variable} "${output}" PARENT_SCOPE)
+endfunction()
+
+function(git_latest_commit variable path)
+	execute_process(COMMAND ${GIT_EXECUTABLE} "rev-parse" "--short" "HEAD"
+		WORKING_DIRECTORY "${path}"
+		RESULT_VARIABLE result
+		OUTPUT_VARIABLE output
+		ERROR_QUIET
+		OUTPUT_STRIP_TRAILING_WHITESPACE
+	)
+
 	set(${variable} "${output}" PARENT_SCOPE)
 endfunction()
\ No newline at end of file

src/config.h.in

@@ -21,8 +21,6 @@
 
 #define SRB2_COMP_REVISION    "${SRB2_COMP_REVISION}"
 #define SRB2_COMP_BRANCH      "${SRB2_COMP_BRANCH}"
-#define SRB2_GIT_DESCRIBE     "${SRB2_GIT_DESCRIBE}"
-#define SRB2_GIT_BRANCH       "${SRB2_GIT_BRANCH}"
 
 #define CMAKE_ASSETS_DIR      "${CMAKE_SOURCE_DIR}/assets"