[PATCH v4 2/3] apply: make i-t-a entries never match worktree

["Raymond E. Pasco" <ray@ameretat.dev>]

By definition, an intent-to-add index entry can never match the
worktree, because worktrees have no concept of intent-to-add entries.
Therefore, "apply --index" should always fail on intent-to-add paths.

Because check_preimage() calls verify_index_match(), it already fails
for patches other than creation patches, which check_preimage() ignores.
This patch adds a check to check_preimage()'s rough equivalent for
creation patches, check_to_create().

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Raymond E. Pasco <ray@ameretat.dev>
---
 apply.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/apply.c b/apply.c
index 4cba4ce71a..6328591489 100644
--- a/apply.c
+++ b/apply.c
@@ -3754,6 +3754,21 @@ static int check_to_create(struct apply_state *state,
 			return EXISTS_IN_INDEX;
 	}
 
+	/* If the new path to be added has an intent-to-add entry, then
+	 * by definition it does not match what is in the work tree. So
+	 * "apply --index" should always fail in this case. Patches other
+	 * than creation patches are already held to this standard by
+	 * check_preimage() calling verify_index_match().
+	 */
+	if (state->check_index && !state->cached) {
+		int pos = index_name_pos(state->repo->index, new_name,
+					 strlen(new_name));
+		if (pos >= 0 &&
+		    state->repo->index->cache[pos]->ce_flags & CE_INTENT_TO_ADD)
+			return error(_("%s: does not match index"), new_name);
+	}
+
+
 	if (state->cached)
 		return 0;
 
-- 
2.28.0.2.g72bf77540a.dirty