static/tinymce/tiny_mce_src.js
function renderBlockOnIE(block) {
				var oldRng;

				if (tinymce.isIE && dom.isBlock(block)) {
					oldRng = selection.getRng();
					block.appendChild(dom.create('span', null, '\u00a0'));
					selection.select(block);
					block.lastChild.outerHTML = '';
					selection.setRng(oldRng);
				}
			}
function renderBlockOnIE(block) {
				var oldRng;

				if (tinymce.isIE && dom.isBlock(block)) {
					oldRng = selection.getRng();
					block.appendChild(dom.create('span', null, '\u00a0'));
					selection.select(block);
					block.lastChild.outerHTML = '';
					selection.setRng(oldRng);
				}
			}
Renders empty block on IE