Jeff King: > diff --git a/Makefile b/Makefile > index 8e4081e06..7c4906250 100644 > --- a/Makefile > +++ b/Makefile > @@ -1386,6 +1390,11 @@ ifdef APPLE_COMMON_CRYPTO > SHA1_MAX_BLOCK_SIZE = 1024L*1024L*1024L > endif > > +ifdef USE_SHA1DC > + SHA1_HEADER = "sha1dc/sha1.h" > + LIB_OBJS += sha1dc/sha1.o > + LIB_OBJS += sha1dc/ubc_check.o > +else > ifdef BLK_SHA1 > SHA1_HEADER = "block-sha1/sha1.h" > LIB_OBJS += block-sha1/sha1.o > @@ -1403,6 +1412,7 @@ else > endif > endif > endif > +endif This sets SHA1_MAX_BLOCK_SIZE and the compiler flags for Apple CommonCrypto even if the user selects USE_SHA1DC. The same happens for BLK_SHA1. Is this intended? > +void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *vdata, unsigned long len) > +{ > + const char *data = vdata; > + /* We expect an unsigned long, but sha1dc only takes an int */ > + while (len > INT_MAX) { > + SHA1DCUpdate(ctx, data, INT_MAX); > + data += INT_MAX; > + len -= INT_MAX; > + } > + SHA1DCUpdate(ctx, data, len); > +} I think you can simply change the len parameter from unsigned into size_t (or unsigned long) in SHA1DCUpdate(). https://github.com/cr-marcstevens/sha1collisiondetection/pull/6