[PATCH 3/4] commit: don't count i-t-a entries when checking if the new commit is empty

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

i-t-a entries are excluded from tree building. Relying solely on active_nr
(or diff without --shift-ita) may lead to empty commits sometimes, when
i-t-a entries are the only ones "changed" in the index.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 builtin/commit.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/builtin/commit.c b/builtin/commit.c
index fcfaa2b..e98ca8a 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -894,9 +894,14 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		if (amend)
 			parent = "HEAD^1";
 
-		if (get_sha1(parent, sha1))
-			commitable = !!active_nr;
-		else {
+		if (get_sha1(parent, sha1)) {
+			int i, ita_nr = 0;
+
+			for (i = 0; i < active_nr; i++)
+				if (ce_intent_to_add(active_cache[i]))
+					ita_nr++;
+			commitable = active_nr - ita_nr == 0;
+		} else {
 			/*
 			 * Unless the user did explicitly request a submodule
 			 * ignore mode by passing a command line option we do
@@ -910,6 +915,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 			if (ignore_submodule_arg &&
 			    !strcmp(ignore_submodule_arg, "all"))
 				diff_flags |= DIFF_OPT_IGNORE_SUBMODULES;
+			diff_flags |= DIFF_OPT_SHIFT_INTENT_TO_ADD;
 			commitable = index_differs_from(parent, diff_flags);
 		}
 	}
-- 
2.8.2.524.g6ff3d78