Bug 145244

Summary:	Page fails to update CSS sometimes when styles are dynamically injected into the page
Product:	WebKit	Reporter:	dak
Component:	Layout and Rendering	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	dak
Priority:	P2
Version:	528+ (Nightly build)
Hardware:	Mac (Intel)
OS:	OS X 10.10

Description dak 2015-05-20 22:30:32 PDT

WebKit is apparently failing to update its CSS and redraw the page when <style> tags are dynamically injected into a page.

In the failing code, the <style> tags are being injected inside of the body tag (as <style scoped> — scoped isn't supported yet, but the styles should still apply globally). I've not yet confirmed whether or not this is a necessary condition for the issue.

I've been attempting to create a simplified test case for this issue, but have so far been unable to do so. There may be an element of complexity/timing necessary for the issue to manifest itself. At the moment, the issue can be seen at http://32demclub.com (code at https://github.com/DerekKent/32demclub/tree/d0b2dd6dc146b40ea2a7541f1e46522e7eda7711/dist).

I'll update this issue with a test case if/when I'm able to produce one.

Running the following code after the page has rendered fixes the issue:
```
// Updates the CSS, but some DOM elements are missing
var head = $('head');
var style = $('<style>');
head.append(style);
style.remove();

// Restores missing DOM elements
$('#main').get(0).parentNode.style.cssText += ';-webkit-transform:rotateZ(0deg)';
$('#main').get(0).parentNode.offsetHeight;
$('#main').get(0).parentNode.style.cssText += ';-webkit-transform:none';
```

Comment 1 dak 2015-05-20 22:35:16 PDT

Note also that the issue is only apparent on a fresh load with no CSS cached.

Comment 2 dak 2015-05-21 06:46:14 PDT

It appears that under certain conditions, injected stylesheets are not initially appearing in `document.styleSheets` when injected with a <style> tag somewhere other than the <head>.

Forcing the styles to be recalculated fixes the issue.