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Re: Additions to SVG 1.1 2nd Edition Conformance Tests

From: Chris Lilley <chris@w3.org>
Date: Sun, 21 Mar 2010 16:28:42 +0100
Message-ID: <1052659049.20100321162842@w3.org>
To: Johannes Rössel <johannes.roessel@uni-rostock.de>
CC: www-svg@w3.org
On Sunday, March 21, 2010, 1:58:27 PM, Johannes wrote:

JR> Hello,

>> It seems that the test expects this to result in a black line. Can
>> anyone explain why  please? The # does not seem to be valid according
>> to http://dev.w3.org/SVG/profiles/1.1F2/publish/paths.html#PathDataBNF,
>> so unless I'm reading it wrong the path is in error and should not be
>> drawn resulting in a red line being shown.

JR> If I'm reading the text below the BNF rules correctly:

JR> “The processing of the BNF must consume as much of a given BNF 
JR> production as possible, stopping at the point when a character is 
JR> encountered which no longer satisfies the production.”,

JR> then an error in the path data does not cease rendering of the path but
JR> instead tries to recover if possible and still render the path. So for
JR> the test case path data processing should stop when encountering the #
JR> sign but still draw everything that has been encountered until then.


Indeed the test description (view source in the SVG file) says

        The 'path' element's 'pathdata' attribute ignores additional whitespace, newline characters, and commas, and BNF processing consumes as much content as possible, stopping as soon as a character that doesn't satisfy the production is encountered.
        Various black path segments are rendered that each demonstrate one of the parsing rules. Each path segment is placed on top
        of a similar path segment that lacks the particular parsing rule that is being tested. Test passes if no red is visible.

JR> Although the test case then wouldn't show an error condition if a 
JR> renderer decides to skip the # and draw the horizontal line up to 90; 
JR> perhaps that error would have best been inserted in the red line instead
JR> of the black.

Good point, I have made that change.

I also uncommented the test description and marked the test as reviewed.

 Chris Lilley                    mailto:chris@w3.org
 Technical Director, Interaction Domain
 W3C Graphics Activity Lead
 Co-Chair, W3C Hypertext CG
Received on Sunday, 21 March 2010 15:28:44 UTC

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