doc/diff-options: document new --diff-merges features

Document changes in -m and --diff-merges=m semantics, as well as new
--diff-merges=on option.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index aa2b5c11f20bf3c94a9a7b704ac72dfe24b5900d..6d968b9012dcbe56b616f9edd66b1e869d09e2ae 100644 (file)
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -34,7 +34,7 @@ endif::git-diff[]
 endif::git-format-patch[]
 
 ifdef::git-log[]
---diff-merges=(off|none|first-parent|1|separate|m|combined|c|dense-combined|cc)::
+--diff-merges=(off|none|on|first-parent|1|separate|m|combined|c|dense-combined|cc)::
 --no-diff-merges::
        Specify diff format to be used for merge commits. Default is
        {diff-merges-default} unless `--first-parent` is in use, in which case
@@ -45,17 +45,24 @@ ifdef::git-log[]
        Disable output of diffs for merge commits. Useful to override
        implied value.
 +
+--diff-merges=on:::
+--diff-merges=m:::
+-m:::
+       This option makes diff output for merge commits to be shown in
+       the default format. `-m` will produce the output only if `-p`
+       is given as well. The default format could be changed using
+       `log.diffMerges` configuration parameter, which default value
+       is `separate`.
++
 --diff-merges=first-parent:::
 --diff-merges=1:::
        This option makes merge commits show the full diff with
        respect to the first parent only.
 +
 --diff-merges=separate:::
---diff-merges=m:::
--m:::
        This makes merge commits show the full diff with respect to
        each of the parents. Separate log entry and diff is generated
-       for each parent. `-m` doesn't produce any output without `-p`.
+       for each parent.
 +
 --diff-merges=combined:::
 --diff-merges=c:::