t / t4135 / diff-with spaces.diffon commit t2024: Show failure to use refspec when DWIMming remote branch names (ec2764e)
   1--- post image.txt.orig 2010-08-18 20:13:31.544002255 -0500
   2+++ post image.txt      2010-08-18 20:13:31.544002255 -0500
   3@@ -1 +1 @@
   4-preimage
   5+postimage