4 ms·

A Google Chrome 37 Canvas Bug That Affects Certain Flot Charts

28 points by thebear 12y ago

swartkrans 12y ago
You could do a bisect on the source code and find the commit that introduced the bug. You might be able to find a flaw in the code pretty quickly and submit a patch with your report. It also helps to be active on #chromium on Freenode. People will look at your bug if you are active in there.
azakai 12y ago
A link to the reported bug seems missing?
- DannyBee 12y ago
  A little searching finds someone else (AFAICT) reported what i believe is the same bug as well: https://code.google.com/p/chromium/issues/detail?id=412640 https://code.google.com/p/chromium/issues/detail?id=412640 It was responded to immediately, tracked down, and fixed in M38.
  - deleted 12y ago
    [deleted]
    - magicalist 12y ago
      As noted in the bug, the fix went into Chrome 38, currently in beta. I don't have beta installed, but I can confirm it's fixed in dev channel and Canary (Chrome 39).
      - thebear 12y ago
        Thanks, I have updated the blog post accordingly. There is a conspicuous note at the top now saying the problem will be fixed in version 38. I think the blog post still makes sense, as it will be a while for the fix to become effective for everybody.
deleted 12y ago
[deleted]
shurcooL 12y ago
Has anyone else noticed the 4 or more tabs in a row layout bug in latest stable Chrome? https://code.google.com/p/chromium/issues/detail?id=418268 https://code.google.com/p/chromium/issues/detail?id=418268 It's interesting that it happens in .124 but not .122. Does anyone know if it's possible to see the list of changes between those releases?
- jbroman 12y ago
  It's somewhat complicated. The changes to Chromium itself are here: https://chromium.googlesource.com/chromium/src/+log/37.0.2062.122..37.0.2062.124 https://chromium.googlesource.com/chromium/src/+log/37.0.206... But this is more likely to be a result of one of the underlying repositories. For instance, it looks like Blink was rolled back from 091cb19dc52917020bfda19b2a41d8f097c02d92 to 6894b21e75041bc3e050a7591388f866cbe7282b. Thank you for reporting this level of detail; having a narrow revision range is helpful for tracking down bugs.
LukeB_UK 12y ago
Doesn't seem to happen on Chrome 37.0.2062.94 on Linux Mint.
Animats 12y ago
It's not clear from the HTML5 spec (http://www.w3.org/TR/2dcontext/#drawing-paths-to-the-canvas http://www.w3.org/TR/2dcontext/#drawing-paths-to-the-canvas) what's supposed to happen when you try to fill a degenerate polygon. This may be "flot" relying on undefined behavior.
muyyatin 12y ago
I've been tracking a number of differences between how browsers render Canvas content: http://jonathan-olson.com/notes/canvas-browser-specific-quirks http://jonathan-olson.com/notes/canvas-browser-specific-quir..., and take advantage of it to use the same code to generate a different picture in every browser (http://jonathan-olson.com/experiments/browser-specific-content-using-canvas-quirks http://jonathan-olson.com/experiments/browser-specific-conte...) I'll probably need to add this one to the list!

28 points by thebear 12y ago

You could do a bisect on the source code and find the commit that introduced the bug. You might be able to find a flaw in the code pretty quickly and submit a patch with your report. It also helps to be active on #chromium on Freenode. People will look at your bug if you are active in there.

azakai 12y ago

A link to the reported bug seems missing?

DannyBee 12y ago
A little searching finds someone else (AFAICT) reported what i believe is the same bug as well: https://code.google.com/p/chromium/issues/detail?id=412640 https://code.google.com/p/chromium/issues/detail?id=412640 It was responded to immediately, tracked down, and fixed in M38.
- deleted 12y ago
  [deleted]
  - magicalist 12y ago
    As noted in the bug, the fix went into Chrome 38, currently in beta. I don't have beta installed, but I can confirm it's fixed in dev channel and Canary (Chrome 39).
    - thebear 12y ago
      Thanks, I have updated the blog post accordingly. There is a conspicuous note at the top now saying the problem will be fixed in version 38. I think the blog post still makes sense, as it will be a while for the fix to become effective for everybody.

deleted 12y ago

[deleted]

shurcooL 12y ago

Has anyone else noticed the 4 or more tabs in a row layout bug in latest stable Chrome? https://code.google.com/p/chromium/issues/detail?id=418268 https://code.google.com/p/chromium/issues/detail?id=418268 It's interesting that it happens in .124 but not .122. Does anyone know if it's possible to see the list of changes between those releases?

jbroman 12y ago
It's somewhat complicated. The changes to Chromium itself are here: https://chromium.googlesource.com/chromium/src/+log/37.0.2062.122..37.0.2062.124 https://chromium.googlesource.com/chromium/src/+log/37.0.206... But this is more likely to be a result of one of the underlying repositories. For instance, it looks like Blink was rolled back from 091cb19dc52917020bfda19b2a41d8f097c02d92 to 6894b21e75041bc3e050a7591388f866cbe7282b. Thank you for reporting this level of detail; having a narrow revision range is helpful for tracking down bugs.

LukeB_UK 12y ago

Doesn't seem to happen on Chrome 37.0.2062.94 on Linux Mint.

Animats 12y ago

It's not clear from the HTML5 spec (http://www.w3.org/TR/2dcontext/#drawing-paths-to-the-canvas http://www.w3.org/TR/2dcontext/#drawing-paths-to-the-canvas) what's supposed to happen when you try to fill a degenerate polygon. This may be "flot" relying on undefined behavior.

muyyatin 12y ago

I've been tracking a number of differences between how browsers render Canvas content: http://jonathan-olson.com/notes/canvas-browser-specific-quirks http://jonathan-olson.com/notes/canvas-browser-specific-quir..., and take advantage of it to use the same code to generate a different picture in every browser (http://jonathan-olson.com/experiments/browser-specific-content-using-canvas-quirks http://jonathan-olson.com/experiments/browser-specific-conte...) I'll probably need to add this one to the list!