t / t4135 / add-with backslash.diffon commit t/Makefile: check helper scripts for non-portable shell commands too (cd78cea)
   1diff -pruN a/post\image.txt b/post\image.txt
   2--- a/post\image.txt    1969-12-31 18:00:00.000000000 -0600
   3+++ b/post\image.txt    2010-08-18 20:13:31.692002255 -0500
   4@@ -0,0 +1 @@
   5+postimage