tests: functions.sh: test missing git

tests/functions_test

@@ -4,7 +4,8 @@
 init_tests \
 	funcs_check_CBUILD \
 	funcs_check_missing_gcc \
-	funcs_check_missing_apk
+	funcs_check_missing_apk \
+	funcs_check_missing_git
 
 FUNCS=$(atf_get_srcdir)/../functions.sh
 
@@ -25,3 +26,10 @@ funcs_check_missing_apk_body() {
 		-e match:"Unable to deduce build architecture" \
 		sh -e -c "APK=false; . $FUNCS && test -z \"$CBUILD\""
 }
+
+funcs_check_missing_git_body() {
+	atf_check -s exit:0 \
+		-o empty \
+		-e empty \
+		sh -e -c "GIT=false . $FUNCS"
+}