Each overlay load its own styleSheet into document.styleSheets. the result is that we can have multiply copies of the same styleSheet. for example if extension overly for the browser (chrome://browser/content/browser.xul) load <?xml-stylesheet href="chrome://browser/content/browser.css" type="text/css"?> then we will have 2 copies of content/browser.css steps: 1. create new profile 2. install Active Stop Button extension (https://addons.mozilla.org/en-US/firefox/addon/active-stop-button/ ) result: 2 copies of content/browser.css in document.styleSheets
Why is this a Firefox bug? Sounds like the extension shouldn't be doing this: > for example if extension overly for the browser > (chrome://browser/content/browser.xul) load <?xml-stylesheet > href="chrome://browser/content/browser.css" type="text/css"?> then we will have > 2 copies of content/browser.css
maybe extensions shouldn't doing this, but they do. how can you prevent it from happening ? if there is multiply copies of the same styleSheet does it affect computing styles efficiency ?
I don't see how we would prevent it as long as core code supports it. And it probably needs to remain supported: someone may want to load the same stylesheet twice and modify one copy with JS, dynamically disable/enable them, etc.
what about CSS transitions. if you have duplicate rule with CSS transitions what is the expecting effect ?
(In reply to comment #4) > if you have duplicate rule with CSS transitions what is the expecting effect ? One of the rules applies, based on the usual cascade.
Status: NEW → RESOLVED
Last Resolved: 6 years ago
Resolution: --- → INVALID
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