Merge branch 'ab/sha1dc-maint'

The "collision detecting" SHA-1 implementation shipped with 2.13
was quite broken on some big-endian platforms and/or platforms that
do not like unaligned fetches.  Update to the upstream code which
has already fixed these issues.

* ab/sha1dc-maint:
sha1dc: update from upstream

diff --combined Makefile
index 7bea912e5a2ffb6d2293b4b768c4fc39cc8c21b4,ffa6da71b7ccaecd6a1fb449b03d3002d5e15ea8..22e4ef3ac565ab0b8d85cc263beaf0b9b1107afb
--- 1/Makefile
--- 2/Makefile
+++ b/Makefile
@@@ -24,10 -24,8 +24,10 @@@ all:
  # Define NO_OPENSSL environment variable if you do not have OpenSSL.
  # This also implies BLK_SHA1.
  #
 -# Define USE_LIBPCRE if you have and want to use libpcre. git-grep will be
 -# able to use Perl-compatible regular expressions.
 +# Define USE_LIBPCRE if you have and want to use libpcre. Various
 +# commands such as log and grep offer runtime options to use
 +# Perl-compatible regular expressions instead of standard or extended
 +# POSIX regular expressions.
  #
  # Define LIBPCREDIR=/foo/bar if your libpcre header and library files are in
  # /foo/bar/include and /foo/bar/lib directories.
@@@ -844,7 -842,6 +844,7 @@@ LIB_OBJS += streaming.
  LIB_OBJS += string-list.o
  LIB_OBJS += submodule.o
  LIB_OBJS += submodule-config.o
 +LIB_OBJS += sub-process.o
  LIB_OBJS += symlinks.o
  LIB_OBJS += tag.o
  LIB_OBJS += tempfile.o
@@@ -1089,7 -1086,7 +1089,7 @@@ ifdef NO_LIBGEN_
  endif
  
  ifdef USE_LIBPCRE
 -      BASIC_CFLAGS += -DUSE_LIBPCRE
 +      BASIC_CFLAGS += -DUSE_LIBPCRE1
        ifdef LIBPCREDIR
                BASIC_CFLAGS += -I$(LIBPCREDIR)/include
                EXTLIBS += -L$(LIBPCREDIR)/$(lib) $(CC_LD_DYNPATH)$(LIBPCREDIR)/$(lib)
@@@ -1417,7 -1414,14 +1417,14 @@@ els
        DC_SHA1 := YesPlease
        LIB_OBJS += sha1dc/sha1.o
        LIB_OBJS += sha1dc/ubc_check.o
-       BASIC_CFLAGS += -DSHA1_DC
+       BASIC_CFLAGS += \
+               -DSHA1_DC \
+               -DSHA1DC_NO_STANDARD_INCLUDES \
+               -DSHA1DC_INIT_SAFE_HASH_DEFAULT=0 \
+               -DSHA1DC_CUSTOM_INCLUDE_SHA1_C="\"cache.h\"" \
+               -DSHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_C="\"sha1dc_git.c\"" \
+               -DSHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_H="\"sha1dc_git.h\"" \
+               -DSHA1DC_CUSTOM_INCLUDE_UBC_CHECK_C="\"git-compat-util.h\""
  endif
  endif
  endif
@@@ -2241,9 -2245,8 +2248,9 @@@ GIT-BUILD-OPTIONS: FORC
        @echo TAR=\''$(subst ','\'',$(subst ','\'',$(TAR)))'\' >>$@+
        @echo NO_CURL=\''$(subst ','\'',$(subst ','\'',$(NO_CURL)))'\' >>$@+
        @echo NO_EXPAT=\''$(subst ','\'',$(subst ','\'',$(NO_EXPAT)))'\' >>$@+
 -      @echo USE_LIBPCRE=\''$(subst ','\'',$(subst ','\'',$(USE_LIBPCRE)))'\' >>$@+
 +      @echo USE_LIBPCRE1=\''$(subst ','\'',$(subst ','\'',$(USE_LIBPCRE)))'\' >>$@+
        @echo NO_PERL=\''$(subst ','\'',$(subst ','\'',$(NO_PERL)))'\' >>$@+
 +      @echo NO_PTHREADS=\''$(subst ','\'',$(subst ','\'',$(NO_PTHREADS)))'\' >>$@+
        @echo NO_PYTHON=\''$(subst ','\'',$(subst ','\'',$(NO_PYTHON)))'\' >>$@+
        @echo NO_UNIX_SOCKETS=\''$(subst ','\'',$(subst ','\'',$(NO_UNIX_SOCKETS)))'\' >>$@+
        @echo PAGER_ENV=\''$(subst ','\'',$(subst ','\'',$(PAGER_ENV)))'\' >>$@+
@@@ -2274,9 -2277,6 +2281,9 @@@ endi
  ifdef GIT_PERF_MAKE_OPTS
        @echo GIT_PERF_MAKE_OPTS=\''$(subst ','\'',$(subst ','\'',$(GIT_PERF_MAKE_OPTS)))'\' >>$@+
  endif
 +ifdef GIT_PERF_MAKE_COMMAND
 +      @echo GIT_PERF_MAKE_COMMAND=\''$(subst ','\'',$(subst ','\'',$(GIT_PERF_MAKE_COMMAND)))'\' >>$@+
 +endif
  ifdef GIT_INTEROP_MAKE_OPTS
        @echo GIT_INTEROP_MAKE_OPTS=\''$(subst ','\'',$(subst ','\'',$(GIT_INTEROP_MAKE_OPTS)))'\' >>$@+
  endif