Merge branch 'tr/fd-gotcha-fixes'

Finishing touches to an earlier fix already in 'master'.

* tr/fd-gotcha-fixes:
  t0070: test that git_mkstemps correctly checks return value of open()

t/t0070-fundamental.sh

@@ -25,6 +25,10 @@ test_expect_success POSIXPERM,SANITY 'mktemp to unwritable directory prints file
 	grep "cannotwrite/test" err
 '
 
+test_expect_success 'git_mkstemps_mode does not fail if fd 0 is not open' '
+	git commit --allow-empty -m message <&-
+'
+
 test_expect_success 'check for a bug in the regex routines' '
 	# if this test fails, re-build git with NO_REGEX=1
 	test-regex