Bug 189230 – Shipped PNGs include bad profiles: iCCP: known incorrect sRGB profile

• Component: WebKit Misc.
• Status: RESOLVED FIXED

[fwdyi]

There is bad metadata embedded in some of the PNG icons shipped with WebKit.

These lead to warnings being printed to the terminal as libpng complains about them: "iCCP: known incorrect sRGB profile"

This affects software using WebKit as library as well.

https://stackoverflow.com/questions/22745076/libpng-warning-iccp-known-incorrect-srgb-profile has a nice overview and proposed fixes for removing this bad metadata.

This is a list of the affected files:

  ./WebInspectorUI.framework/Versions/A/Resources/Images/[e-mail]
  ./WebInspectorUI.framework/Versions/A/Resources/Images/SliderThumbPressed.png
  ./WebInspectorUI.framework/Versions/A/Resources/Images/[e-mail]
  ./WebInspectorUI.framework/Versions/A/Resources/Images/SliderThumb.png
  ./WebInspectorUI.framework/Versions/A/Resources/Images/[e-mail]
  ./WebInspectorUI.framework/Versions/A/Resources/Images/HoverMenuButton.png
  ./WebInspectorUI.framework/Versions/A/Resources/Images/[e-mail]
  ./WebInspectorUI.framework/Versions/A/Resources/Images/GradientStopSelected.png
  ./WebInspectorUI.framework/Versions/A/Resources/Images/[e-mail]
  ./WebInspectorUI.framework/Versions/A/Resources/Images/GradientStop.png
  ./WebInspectorUI.framework/Versions/A/Resources/Images/DatabaseTable.png
  ./WebInspectorUI.framework/Versions/A/Resources/Images/[e-mail]
  ./WebInspectorUI.framework/Versions/A/Resources/Images/ColorIcon.png
  ./WebCore.framework/Versions/A/Resources/[e-mail]
  ./WebCore.framework/Versions/A/Resources/modern-media-controls/images/[e-mail]
  ./WebCore.framework/Versions/A/Resources/modern-media-controls/images/[e-mail]
  ./WebCore.framework/Versions/A/Resources/[e-mail]
  ./WebCore.framework/Versions/A/Resources/AttachmentPlaceholder.png

Please remove the buggy profiles so that unnecessary warnings are not printed to users and developers.

[Radar WebKit Bug Importer]

<rdar://problem/44050379>

[Blaze Burg]

Would you be interested in writing a patch? I don't have a way to test this easily myself, as the Mac port does not use libpng this way (AFAIK).

[John Friend]

I chased the same bug down and arrived here to report it.
The fix simply requires running imagemagick on the filed as described
in the SO question: "mogrify foo.png".

You can verify the fix by grepping the (binary) file for the chunk tag
"iCCP". After repairing the files grep should report a non-match.

I would submit a patch, but the tree snapshot is 1.8GB compressed (!) and that's too much to ask.

Since the files have been there for 7 years, and libpng1.6 has been yelling for 5, this may seem like a minor nuisance. But my system's log files are littered with these messages, so it *would* be great to fix this.

[John Friend]

Reported to downstream QWebKit as well:

https://bugreports.qt.io/browse/QTBUG-71134

[John Friend]

Please respond. This is a trivial fix for a problem which has been ongoing for years.

[John Friend]

I've been advised by Kevin Kofler on the Redhat bugzilla that

pngcrush -ow -fix file.png

(overwrite file in place, fix)

is a better choice, since it strips the bad tag without altering the image data,
whereas mogrify recompresses it. I've verified that running the command twice on the same file doesn't alter the file hash.

[Don Olmstead]

Created attachment 352904 [details]
PNG run through zopflipng

Here's a png run through zopflipng https://github.com/google/zopfli

I have all the pngs with this locally and am happy to make a patch. Please confirm that it works and I'll make a patch for it all.

[John Friend]

Hi Don, 

I can confirm that libpng no longer produces the error. As I mentioned above, using "pngcrush -ow -fix" removes the bad chunk without recompressing the image data, so using that would be even better.

[Don Olmstead]

Created attachment 353048 [details]
Patch

Runs all pngs through zopflipng.

[Don Olmstead]

I'm guessing the ruby errors in the review patch might be due to this original issue.

[Don Olmstead]

Created attachment 353049 [details]
Patch

[Don Olmstead]

Comment on attachment 353049 [details]
Patch

Forgot a folder...

[Joseph Pecoraro]

Comment on attachment 353049 [details]
Patch

r=me, Looks good on my Mac and the file sizes are dramatically better.

However this misses a few of the pngs that were called out in the bug description. Namely the ones in:

    Source/WebCore/Resources/*.png

This should modify resources like textAreaResizeCorner.png.

[Don Olmstead]

(In reply to Joseph Pecoraro from comment #13)
> Comment on attachment 353049 [details]
> Patch
> 
> r=me, Looks good on my Mac and the file sizes are dramatically better.
> 
> However this misses a few of the pngs that were called out in the bug
> description. Namely the ones in:
> 
>     Source/WebCore/Resources/*.png
> 
> This should modify resources like textAreaResizeCorner.png.

Yea since I'm here I'll just make a script that runs through inside Source but not in Source/ThirdParty and compresses it.

[John Friend]

For future issue, same might apply to PNG data embedded in CSS files. 

$ find -print0 -path '*.css' | xargs -0 grep "data:image/png"

[John Friend]

bump.

[Joseph Pecoraro]

Don, are you able to put up another updated patch, or maybe you'll return to this after your other upstreaming work?

[Don Olmstead]

(In reply to Joseph Pecoraro from comment #17)
> Don, are you able to put up another updated patch, or maybe you'll return to
> this after your other upstreaming work?

Yea I'll get that going after I'm done with a couple patches I have in the pipe.

[John Friend]

bump.

[Don Olmstead]

Created attachment 354526 [details]
Patch

[Don Olmstead]

Comment on attachment 354526 [details]
Patch

This runs through everything. If I went too far with it let me know Joe.

[Joseph Pecoraro]

Comment on attachment 354526 [details]
Patch

r=me

[WebKit Commit Bot]

Comment on attachment 354526 [details]
Patch

Clearing flags on attachment: 354526

Committed r238106: <https://trac.webkit.org/changeset/238106>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[John Friend]

Thanks for fixing.