git-rebase: Add --stat and --no-stat for producing diffstat on rebase

The behavior of --verbose is unchanged, but uses a different state
variable internally, so that the meaning of verbose output may be
expanded without affecting the diffstat. This is also reflected in
the documentation.

The configuration option rebase.stat works the same was as merg.stat,
but the default is currently false.

Signed-off-by: Tor Arne Vestbø <torarnv@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 60 insertions, 9 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index f5152c503..6be2e9935 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1160,6 +1160,10 @@ pull.octopus::
 pull.twohead::
 	The default merge strategy to use when pulling a single branch.
 
+rebase.stat::
+	Whether to show a diffstat of what changed upstream since the last
+	rebase. False by default.
+
 receive.fsckObjects::
 	If it is set to true, git-receive-pack will check all received
 	objects. It will abort in the case of a malformed object or a
diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index da3c38cd6..57bd333f0 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -192,6 +192,13 @@ Alternatively, you can undo the 'git-rebase' with
 
     git rebase --abort
 
+CONFIGURATION
+-------------
+
+rebase.stat::
+	Whether to show a diffstat of what changed upstream since the last
+	rebase. False by default.
+
 OPTIONS
 -------
 <newbase>::
@@ -232,7 +239,15 @@ OPTIONS
 
 -v::
 --verbose::
-	Display a diffstat of what changed upstream since the last rebase.
+	Be verbose. Implies --stat.
+
+--stat::
+	Show a diffstat of what changed upstream since the last rebase. The
+	diffstat is also controlled by the configuration option rebase.stat.
+
+-n::
+--no-stat::
+	Do not show a diffstat as part of the rebase process.
 
 --no-verify::
 	This option bypasses the pre-rebase hook.  See also linkgit:githooks[5].
diff --git a/git-rebase.sh b/git-rebase.sh
index 368c0ef43..26d75662f 100755
--- a/git-rebase.sh
+++ b/git-rebase.sh
@@ -46,6 +46,7 @@ do_merge=
 dotest="$GIT_DIR"/rebase-merge
 prec=4
 verbose=
+diffstat=$(git config --bool rebase.stat)
 git_am_opt=
 rebase_root=
 
@@ -289,8 +290,15 @@ do
 		esac
 		do_merge=t
 		;;
+	-n|--no-stat)
+		diffstat=
+		;;
+	--stat)
+		diffstat=t
+		;;
 	-v|--verbose)
 		verbose=t
+		diffstat=t
 		;;
 	--whitespace=*)
 		git_am_opt="$git_am_opt $1"
@@ -426,18 +434,21 @@ then
 	exit 0
 fi
 
-if test -n "$verbose"
-then
-	echo "Changes from $mb to $onto:"
-	# We want color (if set), but no pager
-	GIT_PAGER='' git diff --stat --summary "$mb" "$onto"
-fi
-
 # Detach HEAD and reset the tree
 echo "First, rewinding head to replay your work on top of it..."
 git checkout -q "$onto^0" || die "could not detach HEAD"
 git update-ref ORIG_HEAD $branch
 
+if test -n "$diffstat"
+then
+	if test -n "$verbose"
+	then
+		echo "Changes from $mb to $onto:"
+	fi
+	# We want color (if set), but no pager
+	GIT_PAGER='' git diff --stat --summary "$mb" "$onto"
+fi
+
 # If the $onto is a proper descendant of the tip of the branch, then
 # we just fast forwarded.
 if test "$mb" = "$branch"
diff --git a/t/t3406-rebase-message.sh b/t/t3406-rebase-message.sh
index 539108094..85fc7c4af 100755
--- a/t/t3406-rebase-message.sh
+++ b/t/t3406-rebase-message.sh
@@ -22,7 +22,8 @@ test_expect_success setup '
 	git checkout topic &&
 	quick_one A &&
 	quick_one B &&
-	quick_one Z
+	quick_one Z &&
+	git tag start
 
 '
 
@@ -41,4 +42,24 @@ test_expect_success 'rebase -m' '
 
 '
 
+test_expect_success 'rebase --stat' '
+        git reset --hard start
+        git rebase --stat master >diffstat.txt &&
+        grep "^ fileX |  *1 +$" diffstat.txt
+'
+
+test_expect_success 'rebase w/config rebase.stat' '
+        git reset --hard start
+        git config rebase.stat true &&
+        git rebase master >diffstat.txt &&
+        grep "^ fileX |  *1 +$" diffstat.txt
+'
+
+test_expect_success 'rebase -n overrides config rebase.stat config' '
+        git reset --hard start
+        git config rebase.stat true &&
+        git rebase -n master >diffstat.txt &&
+        ! grep "^ fileX |  *1 +$" diffstat.txt
+'
+
 test_done