twitter/bootstrap — pull request #5448 by nadarik (2012-10-08 08:35:48+00:00)
Title: Update less/button-groups.less

same with

.btn-group > .btn.large:first-child {
margin-left: 0;
-webkit-border-top-left-radius: 6px;
-moz-border-radius-topleft: 6px;
border-top-left-radius: 6px;
-webkit-border-bottom-left-radius: 6px;
-moz-border-radius-bottomleft: 6px;
border-bottom-left-radius: 6px;
}
.btn-group > .btn.large:last-child,
.btn-group > .large.dropdown-toggle {
-webkit-border-top-right-radius: 6px;
-moz-border-radius-topright: 6px;
border-top-right-radius: 6px;
-webkit-border-bottom-right-radius: 6px;
-moz-border-radius-bottomright: 6px;
border-bottom-right-radius: 6px;
}