Merge branch 'jc/read-tree-ignore'

* jc/read-tree-ignore:
  read-tree: document --exclude-per-directory
  Loosen "working file will be lost" check in Porcelain-ish
  read-tree: further loosen "working file will be lost" check.

git-merge.sh

@@ -265,7 +265,7 @@ f,*)
 	echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
 	git-update-index --refresh 2>/dev/null
 	new_head=$(git-rev-parse --verify "$1^0") &&
-	git-read-tree -u -v -m $head "$new_head" &&
+	git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
 	finish "$new_head" "Fast forward"
 	dropsave
 	exit 0