canvas rendering broken on mac when height = 6000px

UNCONFIRMED
Unassigned

Status

()

Core
Canvas: 2D
UNCONFIRMED
5 years ago
5 years ago

People

(Reporter: hezhenbang, Unassigned)

Tracking

19 Branch
x86
Mac OS X
Points:
---

Firefox Tracking Flags

(Not tracked)

Details

Attachments

(1 attachment)

(Reporter)

Description

5 years ago
Created attachment 726685 [details]
test page

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.22 (KHTML, like Gecko) Chrome/25.0.1364.172 Safari/537.22

Steps to reproduce:

I'm using FF 19.0.2 on Mac and ran this simple html/javascript to draw a line on canvas:

<html>
  <body>
    <canvas id="cv" width="900" height="6000"></canvas>
    <script>
      var canvas = document.getElementById('cv');
      var context = canvas.getContext('2d');

      context.beginPath();
      context.moveTo(10, 10);
      context.lineTo(20, 20);
      context.stroke();
    </script>
  </body>
</html>

(HTML page containing the script above is attached.)


Actual results:

The whole canvas becomes black. The weird thing is that the bug is dependent on the canvas height. If you set the height to 3000px or 9000px, then the bug doesn't occur (i.e. I got a black line with a transparent background on the canvas). The bug only occurs if the height is between 4000px and 8000px, and is independent of the width.

I've also tested that what you draw doesn't matter. The whole canvas becomes black as soon as context.stroke() is called.

I have reproduced this bug on another Mac machine. It's not reproducible on PC.


Expected results:

The canvas should draw a black line with a transparent background no matter what the height is.

Updated

5 years ago
Attachment #726685 - Attachment mime type: text/plain → text/html

Updated

5 years ago
Component: Untriaged → Canvas: 2D
Product: Firefox → Core
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