User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a2pre) Gecko/20100208 Minefield/3.7a2pre (.NET CLR 3.5.30729) Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a2pre) Gecko/20100208 Minefield/3.7a2pre (.NET CLR 3.5.30729) Error: [Exception... "An invalid or illegal string was specified" code: "12" nsresult: "0x8053000c (NS_ERROR_DOM_SYNTAX_ERR)" location: "file:///E:/Program%20Files/Minefield/modules/WindowsPreviewPerTab.jsm Line: 308"] Source File: file:///E:/Program%20Files/Minefield/modules/WindowsPreviewPerTab.jsm Line: 308 Reproducible: Couldn't Reproduce Steps to Reproduce: I was testing closing/dragging/inserting tabs with using taskbar aero peek previews. Not even sure the STR since I wasn't watching the error console, but I did have 2 previews attached to 1 tab, and 1 tab without a preview. Plus I had the download manager window open. Actual Results: let scale = width/this.linkedBrowser.boxObject.width; line 308 ---> ctx.scale(scale, scale); ctx.drawImage(this.canvasPreview, 0, 0);

scale must be infinity or NaN so either width (I forget which width it is at the moment) is 0 or the width of your browser content area is 0. This is an edge case that should be rather easy to handle.

Hovering over links I am getting tons of these: Error: preview is undefined Source File: file:///C:/Program%20Files%20(x86)/Minefield/modules/WindowsPreviewPerTab.jsm Line: 352 Latest trunk hourly introduced it Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a4pre) Gecko/20100405 Minefield/3.7a4pre - Build ID: 20100405123809

Do you have STR for this bug? I would like to make sure it is still happening.

Not yet.

Dennis, any STR for us? Does this still happen with Firefox 4.0 trunk?

I wish I did, I'm tempted to resolve this as works for me.

Is this a duplicate or a predecessor of bug 815237 perhaps?

(In reply to [not reading bugmail] from comment #6) > I wish I did, I'm tempted to resolve this as works for me. Not able to reproduce on Latest Nightly (2013-01-27) and FF 19b3 on Windows 7 x64. As you said in comment 6 this should be Resolved WFM. In anyone can still reproduce this issue on latest Nightly, Aurora or Beta please reopen it.