t/t4013/diff.diff_--line-prefix=abc_master_master^_side

   1 $ git diff --line-prefix=abc master master^ side
   2 abcdiff --cc dir/sub
   3 abcindex cead32e,7289e35..992913c
   4 abc--- a/dir/sub
   5 abc+++ b/dir/sub
   6 abc@@@ -1,6 -1,4 +1,8 @@@
   7 abc  A
   8 abc  B
   9 abc +C
  10 abc +D
  11 abc +E
  12 abc +F
  13 abc+ 1
  14 abc+ 2
  15 abcdiff --cc file0
  16 abcindex b414108,f4615da..10a8a9f
  17 abc--- a/file0
  18 abc+++ b/file0
  19 abc@@@ -1,6 -1,6 +1,9 @@@
  20 abc  1
  21 abc  2
  22 abc  3
  23 abc +4
  24 abc +5
  25 abc +6
  26 abc+ A
  27 abc+ B
  28 abc+ C
  29 $