CMake: Use `git rev-parse HEAD` to get commit hash

CMakeLists.txt

@@ -112,13 +112,17 @@ set(KRITA_GIT_SHA1_STRING "")
 set(KRITA_GIT_BRANCH_STRING "")
 
 include(GetGitRevisionDescription)
-get_git_head_revision(GIT_REFSPEC GIT_SHA1)
+get_git_head_hash(GIT_SHA1)
 get_git_branch(GIT_BRANCH)
 
-if(GIT_SHA1 AND GIT_BRANCH)
-    string(SUBSTRING ${GIT_SHA1} 0 7 GIT_SHA1)
-    set(KRITA_GIT_SHA1_STRING ${GIT_SHA1})
-    set(KRITA_GIT_BRANCH_STRING ${GIT_BRANCH})
+if(GIT_SHA1)
+   string(SUBSTRING ${GIT_SHA1} 0 7 GIT_SHA1)
+   set(KRITA_GIT_SHA1_STRING ${GIT_SHA1})
+   if(GIT_BRANCH)
+       set(KRITA_GIT_BRANCH_STRING ${GIT_BRANCH})
+   else()
+       set(KRITA_GIT_BRANCH_STRING "(detached HEAD)")
+   endif()
 endif()
 
 if(NOT DEFINED RELEASE_BUILD)

cmake/modules/GetGitRevisionDescription.cmake

@@ -128,6 +128,33 @@ function(git_describe _var)
 	set(${_var} "${out}" PARENT_SCOPE)
 endfunction()
 
+function(get_git_head_hash _var)
+	if(NOT GIT_FOUND)
+		find_package(Git QUIET)
+	endif()
+	if(NOT GIT_FOUND)
+		set(${_var} "GIT-NOTFOUND" PARENT_SCOPE)
+		return()
+	endif()
+
+	execute_process(COMMAND
+		"${GIT_EXECUTABLE}"
+		rev-parse --verify HEAD
+		WORKING_DIRECTORY
+		"${CMAKE_SOURCE_DIR}"
+		RESULT_VARIABLE
+		res
+		OUTPUT_VARIABLE
+		out
+		ERROR_QUIET
+		OUTPUT_STRIP_TRAILING_WHITESPACE)
+	if(NOT res EQUAL 0)
+		set(out "${out}-${res}-NOTFOUND")
+	endif()
+
+	set(${_var} "${out}" PARENT_SCOPE)
+endfunction()
+
 function(get_git_branch _var)
 	if(NOT GIT_FOUND)
 		find_package(Git QUIET)

libs/version/kritagitversion.h.cmake

@@ -35,4 +35,11 @@
  */
 #cmakedefine KRITA_GIT_BRANCH_STRING "@KRITA_GIT_BRANCH_STRING@"
 
+/**
+ * @def KRITA_GIT_DESCRIBE_STRING
+ * @ingroup KritaMacros
+ * @brief Indicates the git describe string
+ */
+#cmakedefine KRITA_GIT_DESCRIBE_STRING "@KRITA_GIT_DESCRIBE_STRING@"
+
 #endif /* __KRITA_GIT_VERSION_H */