builtin/apply: move check_apply_state() to apply.c

To libify `git apply` functionality we must make check_apply_state()
usable outside "builtin/apply.c".

Let's do that by moving it into "apply.c".

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/apply.c b/apply.c
index 6e0e992839..2eac3e37a9 100644
--- a/apply.c
+++ b/apply.c
@@ -93,3 +93,35 @@ void clear_apply_state(struct apply_state *state)
 
 	/* &state->fn_table is cleared at the end of apply_patch() */
 }
+
+int check_apply_state(struct apply_state *state, int force_apply)
+{
+	int is_not_gitdir = !startup_info->have_repository;
+
+	if (state->apply_with_reject && state->threeway)
+		return error("--reject and --3way cannot be used together.");
+	if (state->cached && state->threeway)
+		return error("--cached and --3way cannot be used together.");
+	if (state->threeway) {
+		if (is_not_gitdir)
+			return error(_("--3way outside a repository"));
+		state->check_index = 1;
+	}
+	if (state->apply_with_reject)
+		state->apply = state->apply_verbosely = 1;
+	if (!force_apply && (state->diffstat || state->numstat || state->summary || state->check || state->fake_ancestor))
+		state->apply = 0;
+	if (state->check_index && is_not_gitdir)
+		return error(_("--index outside a repository"));
+	if (state->cached) {
+		if (is_not_gitdir)
+			return error(_("--cached outside a repository"));
+		state->check_index = 1;
+	}
+	if (state->check_index)
+		state->unsafe_paths = 0;
+	if (!state->lock_file)
+		return error("BUG: state->lock_file should not be NULL");
+
+	return 0;
+}