Add reference for status letters in documentation.

Also fix error in diff_filepair::status documentation, and point to
the in-code reference as well as the doc.

Signed-off-by: Yann Dirson <ydirson@altern.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt
index 400cbb3b1c..aafd3a3941 100644
--- a/Documentation/diff-format.txt
+++ b/Documentation/diff-format.txt
@@ -46,6 +46,22 @@ That is, from the left to the right:
 . path for "dst"; only exists for C or R.
 . an LF or a NUL when '-z' option is used, to terminate the record.
 
+Possible status letters are:
+
+- A: addition of a file
+- C: copy of a file into a new one
+- D: deletion of a file
+- M: modification of the contents or mode of a file
+- R: renaming of a file
+- T: change in the type of the file
+- U: file is unmerged (you must complete the merge before it can
+be committed)
+- X: "unknown" change type (most probably a bug, please report it)
+
+Status letters C and M are always followed by a score (denoting the
+percentage of similarity between the source and target of the move or
+copy), and are the only ones to be so.
+
 <sha1> is shown as all 0's if a file is new on the filesystem
 and it is out of sync with the index.