1397556 - Fast-path for setting the title for more local pages

Status: RESOLVED WORKSFORME

(Firefox :: Tabbed Browser, enhancement, P5)

Description

[Zibi Braniecki [:zbraniecki][:gandalf]]

As part of bug 1362774 we're enabling a fast-path for about:blank and about:newtab title.

Florian suggested that we could do the same for about:privatebrowsing and about:home as well.

Comment 1

[:Gijs (he/him)]

Um, please be careful because about:blank can be web-controlled, in which case a fixed title would be incorrect because the web page could set a title.

Comment 2

[Zibi Braniecki [:zbraniecki][:gandalf]]

What do you mean by "about:blank can be web-controlled"?

Comment 3

[:Gijs (he/him)]

(In reply to Zibi Braniecki [:gandalf][:zibi] from comment #2)
> What do you mean by "about:blank can be web-controlled"?

let w = window.open("", "_blank");
w.document.title = "Hello Firefox";

Comment 4

[:Gijs (he/him)]

(In reply to :Gijs from comment #3)
> (In reply to Zibi Braniecki [:gandalf][:zibi] from comment #2)
> > What do you mean by "about:blank can be web-controlled"?
> 
> let w = window.open("", "_blank");
> w.document.title = "Hello Firefox";

This stuff is why we have checkEmptyPageOrigin in browser.js, btw. - more details in that code.

Comment 5

[Zibi Braniecki [:zbraniecki][:gandalf]]

Oh, yes, thank you.

This case will work. We only set the "fast-path" title before we load the page (in addTab for example), but then we load it, and from there, we handle every DOMTitleChange with value.

So the opposite may not work:

```
let w = window.open("about:home"); // or any other about: with title
w.document.title = "";
```

because if we see title being empty, we skip it.

But this also doesn't work today, so no regression at least.

Comment 6

[:Gijs (he/him)]

I think this got fixed independently - bug 1427186 fixed about:privatebrowsing, and about:home, about:newtab and about:blank should all be dealt with in https://searchfox.org/mozilla-central/rev/2e5e28f518524f8af5b158ddb605022b6a2d68cf/browser/base/content/tabbrowser.js#1265 .