From: Junio C Hamano <gitster@xxxxxxxxx> If a user wants to experiment with the version of collision detecting sha1 from the submodule, the user needed to not just populate the submodule but also needed to turn the knob. A Makefile trick is easy enough to do so, so let's do this. When somebody with a copy of the submodule populated wants not to use it, that can be done by overriding it in config.mak or from the command line. Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> --- Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Makefile b/Makefile index adeff26d57..eeccbff1cd 100644 --- a/Makefile +++ b/Makefile @@ -993,6 +993,10 @@ EXTLIBS = GIT_USER_AGENT = git/$(GIT_VERSION) +ifeq ($(wildcard sha1collisiondetection/lib/sha1.h),sha1collisiondetection/lib/sha1.h) +DC_SHA1_SUBMODULE = auto +endif + include config.mak.uname -include config.mak.autogen -include config.mak -- 2.13.0.506.g27d5fe0cd