Merge branch 'jk/rev-input-given-fix'

Feeding "$ZERO_OID" to "git log --ignore-missing --stdin", and
running "git log --ignore-missing $ZERO_OID" fell back to start
digging from HEAD; it has been corrected to become a no-op, like
"git log --tags=no-tag-matches-this-pattern" does.

* jk/rev-input-given-fix:
  revision: set rev_input_given in handle_revision_arg()

revision.c

@@ -2017,7 +2017,7 @@ static int handle_dotdot(const char *arg,
 	return ret;
 }
 
-int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
+static int handle_revision_arg_1(const char *arg_, struct rev_info *revs, int flags, unsigned revarg_opt)
 {
 	struct object_context oc;
 	char *mark;
@@ -2092,6 +2092,14 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
 	return 0;
 }
 
+int handle_revision_arg(const char *arg, struct rev_info *revs, int flags, unsigned revarg_opt)
+{
+	int ret = handle_revision_arg_1(arg, revs, flags, revarg_opt);
+	if (!ret)
+		revs->rev_input_given = 1;
+	return ret;
+}
+
 static void read_pathspec_from_stdin(struct strbuf *sb,
 				     struct strvec *prune)
 {
@@ -2703,7 +2711,7 @@ static void NORETURN diagnose_missing_default(const char *def)
  */
 int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct setup_revision_opt *opt)
 {
-	int i, flags, left, seen_dashdash, got_rev_arg = 0, revarg_opt;
+	int i, flags, left, seen_dashdash, revarg_opt;
 	struct strvec prune_data = STRVEC_INIT;
 	const char *submodule = NULL;
 	int seen_end_of_options = 0;
@@ -2792,8 +2800,6 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 			strvec_pushv(&prune_data, argv + i);
 			break;
 		}
-		else
-			got_rev_arg = 1;
 	}
 
 	if (prune_data.nr) {
@@ -2822,7 +2828,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 		opt->tweak(revs, opt);
 	if (revs->show_merge)
 		prepare_show_merge(revs);
-	if (revs->def && !revs->pending.nr && !revs->rev_input_given && !got_rev_arg) {
+	if (revs->def && !revs->pending.nr && !revs->rev_input_given) {
 		struct object_id oid;
 		struct object *object;
 		struct object_context oc;

t/t4202-log.sh

@@ -1850,6 +1850,16 @@ test_expect_success 'log does not default to HEAD when rev input is given' '
 	test_must_be_empty actual
 '
 
+test_expect_success 'do not default to HEAD with ignored object on cmdline' '
+	git log --ignore-missing $ZERO_OID >actual &&
+	test_must_be_empty actual
+'
+
+test_expect_success 'do not default to HEAD with ignored object on stdin' '
+	echo $ZERO_OID | git log --ignore-missing --stdin >actual &&
+	test_must_be_empty actual
+'
+
 test_expect_success 'set up --source tests' '
 	git checkout --orphan source-a &&
 	test_commit one &&

t/t6018-rev-list-glob.sh

@@ -345,6 +345,11 @@ test_expect_success 'rev-list should succeed with empty output with empty glob'
 	test_must_be_empty actual
 '
 
+test_expect_success 'rev-list should succeed with empty output when ignoring missing' '
+	git rev-list --ignore-missing $ZERO_OID >actual &&
+	test_must_be_empty actual
+'
+
 test_expect_success 'shortlog accepts --glob/--tags/--remotes' '
 
 	compare shortlog "subspace/one subspace/two" --branches=subspace &&