[OPEN] [#284] IE8 crashes and sometimes forces machine to restart

[jchau]

We launched our new application with Ext.NET 2.0. Some of our clients are reporting IE crashes whenever they use the application. Using their machine, I get the same crash / freezing when visiting Examples2.Ext.Net but not when visiting demo page at ExtJS. This leads me to believe it is due to Ext.NET js files and not ExtJS. If they disabled a specific add-on, it's fine. This add-on is a medical software add-on called Synapse BHO by Fujifilm. I believe it is used to view X-Rays online. We do not have access to install that add-on. What kind of information do you need to debug this issue? About 10% of our client base can not use the application at this moment.

[jchau]

I attached screenshots of the error.

[Vladimir]

I am affraid that without that addon we cannot say anything concrete.

If you have access to their computers then you can use the following approach:
- build simple page with extjs, add extnet-all-debug.js file to that page
- run it, if the browser is crashed then need to remove code from extnet-all.js step by step until crashing is gone. It will allow you to locate the code which causes the crashing

What kind of information do you need to debug this issue?

Does IE8 write any logs during crashing?

[jchau]

I narrowed things down to the following line:

Ext.net.ResourceMgr.registerCssClass("Ext.Net.CSS", buf.join());

That line eventually calls:

Ext.util.CSS.cacheStyleSheet

That function fails at

len = imports ? imports.length : 0

With add-in enabled, IE crashes. With add-in disabled, an error of 'Permission denied' is thrown. Please let me know if you need more info. I am not sure why accessing imports.length will throw an exception.

[Vladimir]

I has the similar issue with iE6
http://www.sencha.com/forum/showthre...s-IE6-crashing

What if to deactivate that function

Ext.util.CSS.cacheStyleSheet = Ext.emptyFn;

Does it help? Is it somehow affected on other functionality?

[jchau]

I found that by setting stylesheet.imports to empty array during registerCssClass, it fixes the issue. I am assuming that since this styles are generated dynamically, there shouldn't be additional imports...

                    document.styleSheets["extnet-resources"].cssText += cssClass;
  		    document.styleSheets["extnet-resources"].imports = [];

[jchau]

I has the similar issue with iE6
http://www.sencha.com/forum/showthre...s-IE6-crashing

What if to deactivate that function

Ext.util.CSS.cacheStyleSheet = Ext.emptyFn;

Does it help? Is it somehow affected on other functionality?

I dont think it's wise to deactivate a core util funciton. It must exist for a reason. PLUS, this is a function in your script that runs as soon as the js file is loaded. So even if I include that override, your lines of code already ran. I have to somehow inject that fix between the loading of ExtJS and ExtNET files...which I dont think I can easily without disabling your auto script includes.

[Vladimir]

PLUS, this is a function in your script that runs as soon as the js file is loaded. So even if I include that override, your lines of code already ran. I have to somehow inject that fix between the loading of ExtJS and ExtNET files...which I dont think I can easily without disabling your auto script includes.

You can use ext:ResourcePlaceHolder to place your own overrides after Ext.Net script files but before init block execution

<ext:ResourcePlaceHolder runat="server" Mode="ScriptFiles" />
    <script type="text/javascript">
        //my overrides
    </script>

[jchau]

What about setting stylesheet.imports = [] ? Is that something you can fix in SVN? Right now, I am going to modify the file on my local repo and rebuild the dll and swap that into our production servers. But next time I get latest, I would like this fix to be incorporated. I really do not want to deactivate a core util function. By the sound of the function name, it's to speed up CSS class lookups. It's probably used during layouts and layout is already slow enough =P.

[jchau]

I bet imports=[] will fix your IE6 crashes too =P