Merge branch 'jg/t3429-test-path-is-file' into seen

A test script has been modernized to use 'test_path_is_file'
instead of 'test -e' to verify the existence of a file.

* jg/t3429-test-path-is-file:
  t3429: use test_path_is_file helper

t/t3429-rebase-edit-todo.sh

@@ -14,7 +14,7 @@ test_expect_success 'setup' '
 test_expect_success 'rebase exec modifies rebase-todo' '
 	todo=.git/rebase-merge/git-rebase-todo &&
 	git rebase HEAD~1 -x "echo exec touch F >>$todo" &&
-	test -e F
+	test_path_is_file F
 '
 
 test_expect_success 'rebase exec with an empty list does not exec anything' '