add-patch: let options a and d roll over like y and n

Options a and d stage and unstage all undecided hunks towards the bottom
of the array of hunks, respectively, and then roll over to the very
first hunk.  The first part is similar to y and n if the current hunk is
the last one in the array, but they roll over to the next undecided
hunk if there is any.  That's more useful; do it for a and d as well.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

add-patch.c

diff --git a/add-patch.c b/add-patch.c
index 4f314c1..6da13a7 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -1418,6 +1418,17 @@ static size_t inc_mod(size_t a, size_t m)
 	return a < m - 1 ? a + 1 : 0;
 }
 
+static bool get_first_undecided(const struct file_diff *file_diff, size_t *idx)
+{
+	for (size_t i = 0; i < file_diff->hunk_nr; i++) {
+		if (file_diff->hunk[i].use == UNDECIDED_HUNK) {
+			*idx = i;
+			return true;
+		}
+	}
+	return false;
+}
+
 static int patch_update_file(struct add_p_state *s,
 			     struct file_diff *file_diff)
 {
@@ -1572,6 +1583,8 @@ static int patch_update_file(struct add_p_state *s,
 					if (hunk->use == UNDECIDED_HUNK)
 						hunk->use = USE_HUNK;
 				}
+				if (!get_first_undecided(file_diff, &hunk_index))
+					hunk_index = 0;
 			} else if (hunk->use == UNDECIDED_HUNK) {
 				hunk->use = USE_HUNK;
 			}
@@ -1582,6 +1595,8 @@ static int patch_update_file(struct add_p_state *s,
 					if (hunk->use == UNDECIDED_HUNK)
 						hunk->use = SKIP_HUNK;
 				}
+				if (!get_first_undecided(file_diff, &hunk_index))
+					hunk_index = 0;
 			} else if (hunk->use == UNDECIDED_HUNK) {
 				hunk->use = SKIP_HUNK;
 			}

t/t3701-add-interactive.sh

diff --git a/t/t3701-add-interactive.sh b/t/t3701-add-interactive.sh
index 385e55c..9d81b05 100755
--- a/t/t3701-add-interactive.sh
+++ b/t/t3701-add-interactive.sh
@@ -1364,24 +1364,24 @@
 	test_cmp expect actual
 '
 
-test_expect_success 'options y, n, j, k, e roll over to next undecided (1)' '
+test_expect_success 'options y, n, a, d, j, k, e roll over to next undecided (1)' '
 	test_write_lines a b c d e f g h i j k l m n o p q >file &&
 	git add file &&
 	test_write_lines X b c d e f g h X j k l m n o p X >file &&
 	test_set_editor : &&
-	test_write_lines g3 y g3 n g3 j g3 e k q | git add -p >out &&
-	test_write_lines 1  3 1  3 1  3 1  3 1 2 >expect &&
+	test_write_lines g3 y g3 n g3 a g3 d g3 j g3 e k q | git add -p >out &&
+	test_write_lines 1  3 1  3 1  3 1  3 1  3 1  3 1 2 >expect &&
 	sed -n -e "s-/.*--" -e "s/^(//p" <out >actual &&
 	test_cmp expect actual
 '
 
-test_expect_success 'options y, n, j, k, e roll over to next undecided (2)' '
+test_expect_success 'options y, n, a, d, j, k, e roll over to next undecided (2)' '
 	test_write_lines a b c d e f g h i j k l m n o p q >file &&
 	git add file &&
 	test_write_lines X b c d e f g h X j k l m n o p X >file &&
 	test_set_editor : &&
-	test_write_lines y g3 y g3 n g3 j g3 e g1 k q | git add -p >out &&
-	test_write_lines 1 2  3 2  3 2  3 2  3 2  1 2 >expect &&
+	test_write_lines y g3 y g3 n g3 a g3 d g3 j g3 e g1 k q | git add -p >out &&
+	test_write_lines 1 2  3 2  3 2  3 2  3 2  3 2  3 2  1 2 >expect &&
 	sed -n -e "s-/.*--" -e "s/^(//p" <out >actual &&
 	test_cmp expect actual
 '