Do not use GUID on dir in git init --shared=all on FreeBSD

It does not allow changing the bit to a non-root user.
This fixes t1301-shared-repo.sh on the platform.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -478,6 +478,7 @@ ifeq ($(uname_S),FreeBSD)
 	NO_MEMMEM = YesPlease
 	BASIC_CFLAGS += -I/usr/local/include
 	BASIC_LDFLAGS += -L/usr/local/lib
+	DIR_HAS_BSD_GROUP_SEMANTICS = YesPlease
 endif
 ifeq ($(uname_S),OpenBSD)
 	NO_STRCASESTR = YesPlease
@@ -747,6 +748,9 @@ ifdef THREADED_DELTA_SEARCH
 	EXTLIBS += -lpthread
 	LIB_OBJS += thread-utils.o
 endif
+ifdef DIR_HAS_BSD_GROUP_SEMANTICS
+	COMPAT_CFLAGS += -DDIR_HAS_BSD_GROUP_SEMANTICS
+endif
 
 ifeq ($(TCLTK_PATH),)
 NO_TCLTK=NoThanks

git-compat-util.h

@@ -437,4 +437,10 @@ void git_qsort(void *base, size_t nmemb, size_t size,
 #define qsort git_qsort
 #endif
 
+#ifndef DIR_HAS_BSD_GROUP_SEMANTICS
+# define FORCE_DIR_SET_GID S_ISGID
+#else
+# define FORCE_DIR_SET_GID 0
+#endif
+
 #endif

path.c

@@ -283,7 +283,7 @@ int adjust_shared_perm(const char *path)
 			    ? (S_IXGRP|S_IXOTH)
 			    : 0));
 	if (S_ISDIR(mode))
-		mode |= S_ISGID;
+		mode |= FORCE_DIR_SET_GID;
 	if ((mode & st.st_mode) != mode && chmod(path, mode) < 0)
 		return -2;
 	return 0;