Junio C Hamano <gitster@xxxxxxxxx> writes: > But when somebody (like me?) feels strongly enough, such a change > can always come on top of this patch, so let's have this > manual-configuration-only version as our first step. Just so that I have something I can come back to, here it is with a log message. -- >8 -- Subject: [PATCH] sha1collisiondetection: automatically enable when submodule is populated 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, e.g. "make DC_SHA1_SUBMODULE= all". Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx> --- Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Makefile b/Makefile index 6baad1669e..8d33936a12 100644 --- a/Makefile +++ b/Makefile @@ -989,6 +989,10 @@ 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 -- 2.13.0-440-g3ce6d2d5b8