t / t4135 / damaged.diffon commit shallow.c: the 8 steps to select new commits for .git/shallow (58babff)
   1diff -pruN a/postimage.txt b/postimage.txt
   2--- a/postimage.txt     1969-12-31 18:00:00.000000000 -0600
   3+++ b/postimage.txt     2010-08-18 20:13:31.484002255 -0500
   4@@ -0,0 +1 @@
   5+postimage