When we are drawing tabs in the titlebar, there is an extra black border on the top of the window. This is noticeable when the top border is above a lighter background or when you try to have the window touching the menubar and see the gap. I don't see this on 10.9 and don't have anything between 10.6 and 10.9 to test with. I can't reproduce in Firefox 28 so this is likely an Australis regression related to tabs in the titlebar. I suspect this is a Cocoa widget issue and not a theme bug.

I think I explained this away in bug 988474. Can you see if you have OMTC disabled? If so, can you re-enable it and see if the problem goes away?

It's forcibly disabled by the driver blocklist so I don't get HWA and continue to see the problem. I agree it's not a high priority but it seems like every 10.6 user sees this. Not sure about 10.7 or 10.8.

For what it's worth, I don't see this bug on OS X 10.6.8, with or without HWA. I tested with today's m-c nightly on a MacBookPro8,2 (from 2009, I think). Here's the Graphics section of about:support when running with "use hardware acceleration when available": Graphics Device ID 0x 126 GPU Accelerated Windows 1/1 OpenGL (OMTC) Vendor ID 0x8086 WebGL Renderer ATI Technologies Inc. -- ATI Radeon HD 6750M OpenGL Engine windowLayerManagerRemote true AzureCanvasBackend quartz AzureContentBackend quartz AzureFallbackCanvasBackend none AzureSkiaAccelerated 0

I am seeing this bug on OS X 10.6.8 whether or not "Use hardware acceleration when available" is checked. Graphics Device ID 0x2a02 GPU Accelerated Windows 0/1 Basic Vendor ID 0x8086 windowLayerManagerRemote false AzureCanvasBackend quartz AzureContentBackend quartz AzureFallbackCanvasBackend none AzureSkiaAccelerated 0

Note: I am seeing the black border at all time, not just when drawing tabs. This is on a Macbook4,1 (mid-2008)

Sounds like a blacklisted driver. sam, can you tell us more about your graphics hardware? If you go into your Apple menu, and choose "About This Mac", and then choose "More Info..." at the bottom, and then choose "Graphics/Displays" in the left hand tree, can you paste what shows up on the right?

Here you go: Intel GMA X3100: Chipset Model: GMA X3100 Type: GPU Bus: Built-In VRAM (Total): 144 MB Vendor: Intel (0x8086) Device ID: 0x2a02 Revision ID: 0x0003 Displays: Color LCD: Resolution: 1280 x 800 Pixel Depth: 32-Bit Color (ARGB8888) Main Display: Yes Mirror: Off Online: Yes Built-In: Yes Display Connector: Status: No Display Connected

Thanks sam! smichaud - is the above information useful in determining what's going on here?

> smichaud - is the above information useful in determining what's going on here? I don't know. I know next to nothing about driver blacklisting, and how that works. Do you have a list of blacklisted drivers? Do you know of any documentation on the subject?

(In reply to Steven Michaud from comment #10) > > smichaud - is the above information useful in determining what's going on here? > > I don't know. I know next to nothing about driver blacklisting, and how > that works. > > Do you have a list of blacklisted drivers? Do you know of any documentation > on the subject? Over to BenWa who, I believe, knows plenty about blacklisted drivers etc.

This looks like a manifestation of bug 999445. Sam can you tell your exact macbook model? Apple Logo in top left->About this mac->More Info->System Report->Copy of the first 'Hardware' page. Maybe I can get my hand on one here and save some back and forth. Could you try to go in about:config, set layers.acceleration.force-enabled to true, restart, and go to about:support and see if it initialized? Be careful that if the driver is really bad there's a small chance you might get startup crashes, if so open in safe mode and restore the preference (or flip it manually in prefs.js) but that unlikely to happen.

I set layers.acceleration.force-enabled to true, restarted, but the issue persists. Here is the Hardware Overview from my machine, let me know if you need more information: Hardware Overview: Model Name: MacBook Model Identifier: MacBook4,1 Processor Name: Intel Core 2 Duo Processor Speed: 2.4 GHz Number Of Processors: 1 Total Number Of Cores: 2 L2 Cache: 3 MB Memory: 4 GB Bus Speed: 800 MHz Boot ROM Version: MB41.00C1.B00 SMC Version (system): 1.31f1 Serial Number (system): W8809DUH0P1 Hardware UUID: 548676BA-5EDA-5729-B895-B1BBCFCA9029 Sudden Motion Sensor: State: Enabled

Does about:support show any GPU windows?

BenWa, See my comment 5 above; I think that means there are no GPU windows.

Changing the preference could of forced a GPU windows. But since the bug is still there I assume it likely did not.

I want to report this bug too. I'm on Lion 10.7.5 Macbook4,1 with X3100. I don't have the "use hardware acceleration" enabled in settings. Please see the attachment.

Same line present on OS X 10.9.3 if the hardware acceleration is inactivated.

NSRectFill uses "operator source" for drawing, which means "replace the pixel that was there before with the new color". When drawing partially-transparent colors, this doesn't blend the colors the way we want. What we actually want is "operator source over". With hardware acceleration enabled this is not a problem, because in that case the highlight line is drawn into the titlebar buffer which is mostly transparent (except for the buttons in the titlebar) so we don't erase anything. The corresponding "source over" composition is done by CompositorOGL in that case.

Comment on attachment 8448736 [details] [diff] [review] fix Sounds good to me.

Hello, in firefox 31 the issue is still there. Have I well understood it's going to be fixed in ff33? Thanks.

Yes, although perhaps we can uplift to 32... Markus, would you consider that safe? :-)

In the end it's not that big deal, it doesn't compromise ff usage and moreover I'm not a developer...I just report bugs because I love firefox :)

Comment on attachment 8448736 [details] [diff] [review] fix Good idea, this is such a simple patch that we may as well get it out to the affected users sooner. Approval Request Comment [Feature/regressing bug #]: Australis / drawing in the titlebar [User impact if declined]: cosmetic issue for users without hardware acceleration [Describe test coverage new/current, TBPL]: none [Risks and why]: lowest risk ever, extremely simple, has baked on Nightly for over three weeks [String/UUID change made/needed]: none

Reproduced the initial issue on both Mac OS 10.6.8 and 10.9.4 with HWA disabled. The issue no longer reproduces on: - Firefox 32 Beta 2 - BuildID: 20140728123914 - User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:32.0) Gecko/20100101 Firefox/32.0 - Aurora 33 (latest) - BuildID: 20140729004006 - User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:33.0) Gecko/20100101 Firefox/33.0 - Nightly 34 (latest) - BuildID: 20140729030202 - User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:34.0) Gecko/20100101 Firefox/34.0