Merge branch 'sg/blame-in-bare-start-at-head'

"git blame -- path" in a non-bare repository starts blaming from
the working tree, and the same command in a bare repository errors
out because there is no working tree by definition.  The command
has been taught to instead start blaming from the commit at HEAD,
which is more useful.

* sg/blame-in-bare-start-at-head:
  blame: default to HEAD in a bare repo when no start commit is given

Author: gitster

builtin/blame.c

@@ -27,6 +27,7 @@
 #include "object-store.h"
 #include "blame.h"
 #include "string-list.h"
+#include "refs.h"
 
 static char blame_usage[] = N_("git blame [<options>] [<rev-opts>] [<rev>] [--] <file>");
 
@@ -993,6 +994,18 @@ int cmd_blame(int argc, const char **argv, const char *prefix)
 
 	revs.disable_stdin = 1;
 	setup_revisions(argc, argv, &revs, NULL);
+	if (!revs.pending.nr && is_bare_repository()) {
+		struct commit *head_commit;
+		struct object_id head_oid;
+
+		if (!resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
+					&head_oid, NULL) ||
+		    !(head_commit = lookup_commit_reference_gently(revs.repo,
+							     &head_oid, 1)))
+			die("no such ref: HEAD");
+
+		add_pending_object(&revs, &head_commit->object, "HEAD");
+	}
 
 	init_scoreboard(&sb);
 	sb.revs = &revs;

t/annotate-tests.sh

@@ -68,6 +68,14 @@ test_expect_success 'blame 1 author' '
 	check_count A 2
 '
 
+test_expect_success 'blame in a bare repo without starting commit' '
+	git clone --bare . bare.git &&
+	(
+		cd bare.git &&
+		check_count A 2
+	)
+'
+
 test_expect_success 'blame by tag objects' '
 	git tag -m "test tag" testTag &&
 	git tag -m "test tag #2" testTag2 testTag &&