Jeff King <peff@xxxxxxxx> writes: > +ifdef USE_SHA1DC > + LIB_OBJS += sha1dc/sha1.o > + LIB_OBJS += sha1dc/ubc_check.o > + BASIC_CFLAGS += -DSHA1_SHA1DC The name of this CPP symbol is one difference between this and Linus's version. Wouldn't "-DSHA1_DC" make more sense? Another difference is that your version adds USE_SHA1DC to GIT-BUILD-OPTIONS in patch 5/5; I thought GIT-CFLAGS forces rebuilding and that was sufficient, but GIT-BUILD-OPTIONS is available to tests for introspection, so adding it is needed for that reason.