Merge branch 'nd/reject-empty-shallow-request'

"git fetch --shallow-since=<cutoff>" that specifies the cut-off
point that is newer than the existing history used to end up
grabbing the entire history.  Such a request now errors out.

* nd/reject-empty-shallow-request:
  upload-pack: reject shallow requests that would return nothing

Author: gitster

shallow.c

@@ -191,6 +191,9 @@ struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
 		die("revision walk setup failed");
 	traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
 
+	if (!not_shallow_list)
+		die("no commits selected for shallow requests");
+
 	/* Mark all reachable commits as NOT_SHALLOW */
 	for (p = not_shallow_list; p; p = p->next)
 		p->item->object.flags |= not_shallow_flag;

t/t5500-fetch-pack.sh

@@ -711,6 +711,17 @@ test_expect_success 'fetch shallow since ...' '
 	test_cmp expected actual
 '
 
+test_expect_success 'clone shallow since selects no commits' '
+	test_create_repo shallow-since-the-future &&
+	(
+	cd shallow-since-the-future &&
+	GIT_COMMITTER_DATE="100000000 +0700" git commit --allow-empty -m one &&
+	GIT_COMMITTER_DATE="200000000 +0700" git commit --allow-empty -m two &&
+	GIT_COMMITTER_DATE="300000000 +0700" git commit --allow-empty -m three &&
+	test_must_fail git clone --shallow-since "900000000 +0700" "file://$(pwd)/." ../shallow111
+	)
+'
+
 test_expect_success 'shallow clone exclude tag two' '
 	test_create_repo shallow-exclude &&
 	(