Merge branch 'jc/maint-1.6.1-add-u-remove-conflicted' into maint-1.6.1

* jc/maint-1.6.1-add-u-remove-conflicted:
  add -u: do not fail to resolve a path as deleted

read-cache.c

@@ -1574,6 +1574,26 @@ static void update_callback(struct diff_queue_struct *q,
 		default:
 			die("unexpected diff status %c", p->status);
 		case DIFF_STATUS_UNMERGED:
+			/*
+			 * ADD_CACHE_IGNORE_REMOVAL is unset if "git
+			 * add -u" is calling us, In such a case, a
+			 * missing work tree file needs to be removed
+			 * if there is an unmerged entry at stage #2,
+			 * but such a diff record is followed by
+			 * another with DIFF_STATUS_DELETED (and if
+			 * there is no stage #2, we won't see DELETED
+			 * nor MODIFIED).  We can simply continue
+			 * either way.
+			 */
+			if (!(data->flags & ADD_CACHE_IGNORE_REMOVAL))
+				continue;
+			/*
+			 * Otherwise, it is "git add path" is asking
+			 * to explicitly add it; we fall through.  A
+			 * missing work tree file is an error and is
+			 * caught by add_file_to_index() in such a
+			 * case.
+			 */
 		case DIFF_STATUS_MODIFIED:
 		case DIFF_STATUS_TYPE_CHANGED:
 			if (add_file_to_index(&the_index, path, data->flags)) {

t/t2200-add-update.sh

@@ -12,7 +12,7 @@ and issues a git add -u with path limiting on "dir" to add
 only the updates to dir/sub.
 
 Also tested are "git add -u" without limiting, and "git add -u"
-without contents changes.'
+without contents changes, and other conditions'
 
 . ./test-lib.sh
 
@@ -128,4 +128,52 @@ test_expect_success 'add -n -u should not add but just report' '
 
 '
 
+test_expect_success 'add -u resolves unmerged paths' '
+	git reset --hard &&
+	one=$(echo 1 | git hash-object -w --stdin) &&
+	two=$(echo 2 | git hash-object -w --stdin) &&
+	three=$(echo 3 | git hash-object -w --stdin) &&
+	{
+		for path in path1 path2
+		do
+			echo "100644 $one 1	$path"
+			echo "100644 $two 2	$path"
+			echo "100644 $three 3	$path"
+		done
+		echo "100644 $one 1	path3"
+		echo "100644 $one 1	path4"
+		echo "100644 $one 3	path5"
+		echo "100644 $one 3	path6"
+	} |
+	git update-index --index-info &&
+	echo 3 >path1 &&
+	echo 2 >path3 &&
+	echo 2 >path5 &&
+	git add -u &&
+	git ls-files -s "path?" >actual &&
+	{
+		echo "100644 $three 0	path1"
+		echo "100644 $one 1	path3"
+		echo "100644 $one 1	path4"
+		echo "100644 $one 3	path5"
+		echo "100644 $one 3	path6"
+	} >expect &&
+	test_cmp expect actual &&
+
+	# Bonus tests.  Explicit resolving
+	git add path3 path5 &&
+	test_must_fail git add path4 &&
+	test_must_fail git add path6 &&
+	git rm path4 &&
+	git rm path6 &&
+
+	git ls-files -s "path?" >actual &&
+	{
+		echo "100644 $three 0	path1"
+		echo "100644 $two 0	path3"
+		echo "100644 $two 0	path5"
+	} >expect
+
+'
+
 test_done