Bug 20174

Summary: weird faint lines on canvas when drawing lines
Product: WebKit Reporter: Ian 'Hixie' Hickson <ian>
Component: WebCore Misc.Assignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: mdelaney7, oliver
Priority: P2 Keywords: NeedsReduction
Version: 528+ (Nightly build)   
Hardware: Mac   
OS: OS X 10.5   
URL: http://www.whatwg.org/issues/data.html

Description Ian 'Hixie' Hickson 2008-07-25 15:16:07 PDT
STEPS TO REPRODUCE
1. load http://www.whatwg.org/issues/data.html
2. zoom in on the top left

ACTUAL RESULTS
faint lines

EXPECTED RESULTS
just the main line

If it's the fault of a bug in my script I apologise in advance. But I don't think it is.
Comment 1 Ian 'Hixie' Hickson 2008-07-25 15:17:05 PDT
also visible on the blue line where the main line jumps up for a bit.
Comment 2 Oliver Hunt 2008-12-29 04:40:16 PST
Slightly more minimal testcase at http://nerget.com/bugs/bug20174.html

The issue is the 'dots' for somereason we occasionally get subpixel lines being drawn back to the origin.  I suspect this is a CG-ism, but it'd be good to know if it occurs in the gtk/qt ports.