[fullscreen addon] Restore width and height when leaving fullscreen

Issue #1761

addon/display/fullscreen.js

@@ -9,8 +9,11 @@
   });
 
   function setFullscreen(cm) {
-    cm.state.restoreScreenScrollPos = {top: window.pageYOffset, left: window.pageXOffset};
-    cm.getWrapperElement().className += " CodeMirror-fullscreen";
+    var wrap = cm.getWrapperElement();
+    cm.state.fullScreenRestore = {scrollTop: window.pageYOffset, scrollLeft: window.pageXOffset,
+                                  width: wrap.style.width, height: wrap.style.height};
+    wrap.style.width = wrap.style.height = "";
+    wrap.className += " CodeMirror-fullscreen";
     document.documentElement.style.overflow = "hidden";
     cm.refresh();
   }
@@ -19,7 +22,8 @@
     var wrap = cm.getWrapperElement();
     wrap.className = wrap.className.replace(/\s*CodeMirror-fullscreen\b/, "");
     document.documentElement.style.overflow = "";
-    var scroll = cm.state.restoreScreenScrollPos;
+    var info = cm.state.fullScreenRestore;
+    wrap.style.width = info.width; wrap.style.height = info.height;
     window.scrollTo(scroll.left, scroll.top);
     cm.refresh();
   }