[Webkit-unassigned] [Bug 192807] New: An unexpected 1px line appears when using context.drawImage() method to show a specified part of a JPEG file

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=192807

            Bug ID: 192807
           Summary: An unexpected 1px line appears when using
                    context.drawImage() method to show a specified part of
                    a JPEG file
           Product: WebKit
           Version: Safari 12
          Hardware: iPhone / iPad
                OS: iOS 12
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: Canvas
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: nishiyama.satomi at bpsinc.jp
                CC: dino at apple.com

Created attachment 357545

  --> https://bugs.webkit.org/attachment.cgi?id=357545&action=review

an unexpected 1px red line appears when the context draws JPEG file.

Hello,

I found an issue with JPEG drawing on iOS 12 devices.
An unexpected 1px line appears on a image when I use context.drawImage() method of html to show a specified part of a JPEG file.
It doesn't occur when using iOS12 simulators or iOS11 devices.

[Steps to reproduce the problem]
1. Open 'index.html' on Safari using iPhone/iPad on iOS12.
  This html file shows a specified part of each following file.
       'test.jpg',
       'test.png',
       'test.jp2',
       'test.gif'
2. An unexpected 1px red line appears on 'test.jpg' image. No problems with the other files, though.

[What is the expected behavior?]
No unexpected lines appear on a JPEG image like the other file formats ( : png, jp2, gif).

[What went wrong?]
An unexpected 1px red line appears on a JPEG image.

[Is it a problem with a plugin?]
N/A

[Did this work before?]
N/A

[Does this work in other browsers?]
Yes

Thank you.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20181218/4c1befae/attachment-0001.html>