merge/pull: extend merge.stat configuration variable to cover --compact-summary

Existing `merge.stat` configuration variable is a Boolean that
defaults to `true` to control `git merge --[no-]stat` behaviour.

Extend it to be "Boolean or text", that takes false, true, or
"compact", with the last one triggering the --compact-summary option
introduced earlier.  Any other values are taken as the same as true,
instead of signaling an error---it is not a grave enough offence to
stop their merge.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/Documentation/config/merge.adoc b/Documentation/config/merge.adoc
index 86359f6dd2..15a4c14c38 100644
--- a/Documentation/config/merge.adoc
+++ b/Documentation/config/merge.adoc
@@ -81,8 +81,18 @@ as `false`. Defaults to `conflict`.
 	attributes" in linkgit:gitattributes[5].
 
 `merge.stat`::
-	Whether to print the diffstat between `ORIG_HEAD` and the merge result
-	at the end of the merge.  True by default.
+	What, if anything, to print between `ORIG_HEAD` and the merge result
+	at the end of the merge.  Possible values are:
++
+--
+`false`;; Show nothing.
+`true`;; Show `git diff --diffstat --summary ORIG_HEAD`.
+`compact`;; Show `git diff --compact-summary ORIG_HEAD`.
+--
++
+but any unrecognised value (e.g., a value added by a future version of
+Git) is taken as `true` instead of triggering an error.  Defaults to
+`true`.
 
 `merge.autoStash`::
 	When set to `true`, automatically create a temporary stash entry