[PATCH 3/3] git add --intent-to-add: do not let an empty blob committed by accident

[Junio C Hamano <gitster@pobox.com>]

Writing a tree out of an index with an "intent to add" entry is blocked.
This implies that you cannot "git commit" from such a state; however "git
commit -a" still works.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin-write-tree.c       |    2 +-
 cache-tree.c               |   10 +++++++---
 t/t3701-add-interactive.sh |   18 ++++++++++++++++++
 3 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/builtin-write-tree.c b/builtin-write-tree.c
index 52a3c01..9d64050 100644
--- a/builtin-write-tree.c
+++ b/builtin-write-tree.c
@@ -42,7 +42,7 @@ int cmd_write_tree(int argc, const char **argv, const char *unused_prefix)
 		die("%s: error reading the index", me);
 		break;
 	case WRITE_TREE_UNMERGED_INDEX:
-		die("%s: error building trees; the index is unmerged?", me);
+		die("%s: error building trees", me);
 		break;
 	case WRITE_TREE_PREFIX_ERROR:
 		die("%s: prefix %s not found", me, prefix);
diff --git a/cache-tree.c b/cache-tree.c
index 5f8ee87..3d8f218 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -155,13 +155,17 @@ static int verify_cache(struct cache_entry **cache,
 	funny = 0;
 	for (i = 0; i < entries; i++) {
 		struct cache_entry *ce = cache[i];
-		if (ce_stage(ce)) {
+		if (ce_stage(ce) || (ce->ce_flags & CE_INTENT_TO_ADD)) {
 			if (10 < ++funny) {
 				fprintf(stderr, "...\n");
 				break;
 			}
-			fprintf(stderr, "%s: unmerged (%s)\n",
-				ce->name, sha1_to_hex(ce->sha1));
+			if (ce_stage(ce))
+				fprintf(stderr, "%s: unmerged (%s)\n",
+					ce->name, sha1_to_hex(ce->sha1));
+			else
+				fprintf(stderr, "%s: not added yet\n",
+					ce->name);
 		}
 	}
 	if (funny)
diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index e95663d..473ef85 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -133,6 +133,24 @@ test_expect_success 'real edit works' '
 	test_cmp expected output
 '
 
+test_expect_success 'cannot commit with i-t-a entry' '
+	git reset --hard &&
+	echo xyzzy >rezrov &&
+	echo frotz >nitfol &&
+	git add rezrov &&
+	git add -N nitfol &&
+	test_must_fail git commit
+'
+
+test_expect_success 'can commit with an unrelated i-t-a entry in index' '
+	git reset --hard &&
+	echo xyzzy >rezrov &&
+	echo frotz >nitfol &&
+	git add rezrov &&
+	git add -N nitfol &&
+	git commit -m partial rezrov
+'
+
 if test "$(git config --bool core.filemode)" = false
 then
     say 'skipping filemode tests (filesystem does not properly support modes)'
-- 
1.6.0.4.850.g6bd829