1265261 - problem with canvas and javascript

Status: NEW

(Core :: Graphics: Canvas2D, defect, P3)

Description

[jeanpierreforum]

What did you do?
================
1. i use canvas and javascript
2. 
3. 

What happened?
==============
look with firefox ( bug appears on firefox38.0.1 it work before)and look in chrome and edge
http://websitecreation.canalblog.com/pages/joyeuxnoelrougesilhouettestournantes/28977767.html

the text inside is not visible in firefox

What should have happened?
==========================
look the same in edge and chrome
http://websitecreation.canalblog.com/pages/joyeuxnoelrougesilhouettestournantes/28977767.html

Is there anything else we should know?
======================================
no its just for information

Comment 1

[Paul Pasca[Away. Please needinfo? Paul Oiegas [:pauloiegasSV]]]

User Agent: Mozilla/5.0 (Windows NT 6.1; rv:45.0) Gecko/20100101 Firefox/45.0
Build ID: 20160407164938

I have tested your issue on latest FF release (45.0.2), latest Nightly build (20160424030601) and managed to reproduce it. I have opened the provided link and the text inside the animation is not visible. Chrome and IE displays the text as expected. I went back as far as Firefox 4 and the bug is still reproducible. On some Firefox versions, the animation doesn't even start.

Comment 2

[Timothy Nikkel (:tnikkel)]

A simplified testcase would probably help here.

Comment 3

[jeanpierreforum]

the problem comes from:
the bugs appears with  firefox 38.0.1
affichertexte=function(){console.log("affichertexte");
contextet.save();
contextet.beginPath();
contextet.arc(noelclientwidth*0.5,noelclientheight*0.5,noelclientwidth*0.18, 0, Math.PI * 2, false);//le masque
contextet.clip();

contextet.globalCompositeOperation = 'xor';
contextet.drawImage(this.textenoel,0,0,noelclientwidth,noelclientheight);
contextet.arc(noelclientwidth*0.5,noelclientheight*0.5,noelclientwidth*0.18, 0, Math.PI * 2, false);
contextet.fillStyle = "blue";//mongrad;
contextet.fill();

contextet.closePath();
contextet.restore();
						};

Comment 4

[Timothy Nikkel (:tnikkel)]

Attachment: reduced testcase

Comment 5

[Timothy Nikkel (:tnikkel)]

The problem with the original site (and reduced testcase) regressed between 28 and 29 for me. Specifically:

http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=12d3ba62a599&tochange=34dddf6f7ec1

I suspect bug 603488 is what caused this since it changed how svg images are drawn to canvas. But I'm not sure if there is anything wrong with the code from that bug, it might be exposing another problem somewhere else.

Comment 6

[Timothy Nikkel (:tnikkel)]

Bas, do you have any insight here?

Comment 7

[Bas Schouten (:bas.schouten)]

(In reply to Timothy Nikkel (:tnikkel) from comment #6)
> Bas, do you have any insight here?

Nothing obvious but I suspect I could debug this pretty easily, can you give me an idea of how important this is to fix? I can confirm I can reproduce it.

Comment 8

[Timothy Nikkel (:tnikkel)]

(In reply to Bas Schouten (:bas.schouten) from comment #7)
> can you give
> me an idea of how important this is to fix?

I was hoping you'd have a better idea about that.