Merge branch 'ds/path-walk-1'

Introduce a new API to visit objects in batches based on a common
path, or by type.

* ds/path-walk-1:
  path-walk: drop redundant parse_tree() call
  path-walk: reorder object visits
  path-walk: mark trees and blobs as UNINTERESTING
  path-walk: visit tags and cached objects
  path-walk: allow consumer to specify object types
  t6601: add helper for testing path-walk API
  test-lib-functions: add test_cmp_sorted
  path-walk: introduce an object walk by path

t/test-lib-functions.sh

@@ -1268,6 +1268,16 @@ test_cmp () {
 	eval "$GIT_TEST_CMP" '"$@"'
 }
 
+# test_cmp_sorted runs test_cmp on sorted versions of the two
+# input files. Uses "$1.sorted" and "$2.sorted" as temp files.
+
+test_cmp_sorted () {
+	sort <"$1" >"$1.sorted" &&
+	sort <"$2" >"$2.sorted" &&
+	test_cmp "$1.sorted" "$2.sorted" &&
+	rm "$1.sorted" "$2.sorted"
+}
+
 # Check that the given config key has the expected value.
 #
 #    test_cmp_config [-C <dir>] <expected-value>