clone: allow --no-local to turn off local optimizations

This is basically the same as using "file://", but is a
little less subtle for the end user. It also allows relative
paths to be specified.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-clone.txt

@@ -51,7 +51,9 @@ OPTIONS
 If the repository is specified as a local path (e.g., `/path/to/repo`),
 this is the default, and --local is essentially a no-op.  If the
 repository is specified as a URL, then this flag is ignored (and we
-never use the local optimizations).
+never use the local optimizations).  Specifying `--no-local` will
+override the default when `/path/to/repo` is given, using the regular
+git transport instead.
 +
 To force copying instead of hardlinking (which may be desirable if you
 are trying to make a back-up of your repository), but still avoid the

builtin/clone.c

@@ -38,7 +38,7 @@ static const char * const builtin_clone_usage[] = {
 };
 
 static int option_no_checkout, option_bare, option_mirror, option_single_branch = -1;
-static int option_local, option_no_hardlinks, option_shared, option_recursive;
+static int option_local = -1, option_no_hardlinks, option_shared, option_recursive;
 static char *option_template, *option_depth;
 static char *option_origin = NULL;
 static char *option_branch = NULL;
@@ -70,8 +70,8 @@ static struct option builtin_clone_options[] = {
 		PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
 	OPT_BOOLEAN(0, "mirror", &option_mirror,
 		    "create a mirror repository (implies bare)"),
-	OPT_BOOLEAN('l', "local", &option_local,
-		    "to clone from a local repository"),
+	OPT_BOOL('l', "local", &option_local,
+		"to clone from a local repository"),
 	OPT_BOOLEAN(0, "no-hardlinks", &option_no_hardlinks,
 		    "don't use local hardlinks, always copy"),
 	OPT_BOOLEAN('s', "shared", &option_shared,
@@ -342,7 +342,7 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 		if (!option_no_hardlinks) {
 			if (!link(src->buf, dest->buf))
 				continue;
-			if (option_local)
+			if (option_local > 0)
 				die_errno(_("failed to create link '%s'"), dest->buf);
 			option_no_hardlinks = 1;
 		}
@@ -668,7 +668,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		die(_("repository '%s' does not exist"), repo_name);
 	else
 		repo = repo_name;
-	is_local = path && !is_bundle;
+	is_local = option_local != 0 && path && !is_bundle;
 	if (is_local && option_depth)
 		warning(_("--depth is ignored in local clones; use file:// instead."));
 

t/t5701-clone-local.sh

@@ -124,4 +124,14 @@ test_expect_success 'cloning non-git directory fails' '
 	test_must_fail git clone not-a-git-repo not-a-git-repo-clone
 '
 
+test_expect_success 'cloning file:// does not hardlink' '
+	git clone --bare file://"$(pwd)"/a non-local &&
+	! repo_is_hardlinked non-local
+'
+
+test_expect_success 'cloning a local path with --no-local does not hardlink' '
+	git clone --bare --no-local a force-nonlocal &&
+	! repo_is_hardlinked force-nonlocal
+'
+
 test_done