543534 - navigator.plugins.refresh() always fires "plugins-list-updated" notification when Java is installed

Status: RESOLVED WONTFIX

(Core Graveyard :: Plug-ins, defect)

Description

[u130342]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.1.7; .NET CLR 3.5; ffco7) Gecko/20091221 Firefox/3.5.7
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.1.7; .NET CLR 3.5; ffco7) Gecko/20091221 Firefox/3.5.7

I don't really know whether its really a bug, since documentation is quiet small and I found this out almost accidently.

Even if all plugins are disabled this notification is sent every time.
I didn't install/uninstall/enable/disable any plugin between calls.

I rated it as minor because it seems nobody uses it.


Reproducible: Always

Steps to Reproduce:
1. add a global observer for "plugins-list-updated" 
2. type javascript:navigator.plugins.refresh(); into browser url and press return
3. the global observer will be notified

Actual Results:  
notification for every navigator.plugins.refresh() call

Expected Results:  
only notify when there is a change in the plugin list

Comment 2

[Avi Halachmi (:avih)]

If this bug is indeed a duplicate (per comment #1 ), it should be noted here that there are more manifestations/symptoms, some possibly severe:

1. While on some pages, the addons/plugins window keeps scrolling back to the highlighted addon, making it practically unusable.

2. A Java plugin keeps getting re-enabled even if the user disables it manually (both from within Firefox and from Windows control panel). Closing this sample page "cures" this problem. Re-opening the sample page automatically re-enables the plugin without the user wishing so.

For further info, please read comment 15 of the other bug: https://bugzilla.mozilla.org/show_bug.cgi?id=546437#c15

Comment 3

[Avi Halachmi (:avih)]

After Installing latest Java runtime (SE 6 U18 6.0.180.7) on my main XP/SP3 system, symptom 2 (Java keeps getting re-enabled while on this test page) is not happening anymore.

So while all my plugins are manually disabled, java included, the 1st symptom (addons page jumps to highlighted addon) still happens.

Also, later I removed Java from my computer altogether, and symptom 1 is STILL happening. It probably means this "addon list jumps" thing is completely unrelated to Java.

Here's a list of installed plugins on my Firefox (all successfully manually disabled at the time of testing):

- Adobe Acrobat 8.1.0.137
- IE Tab Plug-in 1.7.0.300
- Java Deployment Toolkit 6.0.180.7 (Yes, even after Uninstalling Java from my PC)
- Microsoft DRM (Netscape Network Object) 9.0.0.4503
- Microsoft DRM (DRM Store Netscape Plugin) 9.0.0.4503
- Mozilla Default Plug-in 1.0.0.15
- Shockwave Flash 10.0.45.2
- Shockwave for Director 11.5.1.601
- Silverlight Plug-in 3.0.40624.0
- Windows Media Player Plug-in DLL 3.0.2.629
- Windows Presentation Foundation 3.5.30729.1

Comment 4

[u130342]

I can't reproduce symptom 1 on a regular base, althoug I think I've seen it once.

I'm adding some test cases.
Note: navigator-refresh-1.html does navigator.plugins.refresh(1); which in turn refreshes the list and a page reload enting in the page reloading infinitely.
The browser keeps responding but on high cpu load.

Comment 5

[u130342]

Attachment: call navigator.plugins.refresh(0);

Comment 6

[u130342]

Attachment: call navigator.plugins.refresh();

Comment 7

[u130342]

Attachment: call navigator.plugins.refresh(1);

Comment 8

[Avi Halachmi (:avih)]

Thanks. I can reproduce the bug (symptom 1 - addon list jumps) with all your your test cases:

Cases of comment 5 and comment 6: trigger symptom 1 on load or reload.
Case of comment 7: continuously triggers it (making the addons list unusable).

I'm curious though, why do web pages have the privilege to refresh the plugins list? I'd consider it a Firefox decision to make, not the page's..

Comment 9

[u130342]

Ok, now I can confirm symtom 1 too, I missed the word selected in the description of Bug 546437 and probably the selected item was asmost always in view on my tests.

In other words: The selected item is scrolled into view. 
I guess the reason why extensions are affected is that all datasources are attached to the same view all the time (http://mxr.mozilla.org/mozilla1.9.2/source/toolkit/mozapps/extensions/content/extensions.js#1191)

It seems there are already some countermeasures (but not effective) to reduce the numer of "plugins-list-updated" notifications (here http://mxr.mozilla.org/mozilla1.9.2/source/modules/plugin/base/src/nsPluginHost.cpp#2583)

Another interesting effect is that the plugin list displayed in my examples varies every time when there are two active plugins (Java/Flash where changing places every time).

Comment 10

[Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.)]

I'm marking this bug as WONTFIX per bug #1269807.

For more information see - https://blog.mozilla.org/futurereleases/2015/10/08/npapi-plugins-in-firefox/