665822 - SVG does not honor textPath startOffset attribute if the textPath contains a tspan

Status: RESOLVED FIXED

(Core :: SVG, defect)

Description

[Adam Henson]

User-Agent:       Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0.1) Gecko/20100101 Firefox/4.0.1
Build Identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0.1) Gecko/20100101 Firefox/4.0.1

Per the w3c spec, SVG textPath elements have a startOffset attribute which can be used to set a (relative or absolute) start point for the text along the path.  If the textPath contains a <tspan> element, Firefox does not honor the startOffset attribute on the parent <textPath>, and instead begins the text at the start of the path.

Reproducible: Always

Steps to Reproduce:
1. Create a path in SVG
2. Create a textPath along this path, with startOffset set to 50%
3. Enter text in the textPath - it should render correctly (beginning halfway along the path)
4. Wrap the above text in a <tspan> (with no attributes) - it will now render incorrectly, at the beginning of the path

Actual Results:  
Text begins at the beginning of the path

Expected Results:  
Text should begin halfway along the path

See attachments for test cases.

Comment 1

[Adam Henson]

Attachment: Example of working and broken SVG textPaths

Comment 2

[Robert Longson [:longsonr]]

Thanks for the minimal testcase Adam. Worth their weight in gold those are :-)

Comment 3

[(mostly gone) XtC4UaLL [:xtc4uall]]

Confirmed against Mozilla/5.0 (Windows NT 5.1; rv:7.0a1) Gecko/20110621 Firefox/7.0a1 ID:20110621030803

Comment 4

[Robert Longson [:longsonr]]

It's the whitespace before the start of the textPath node that causes the problem. Remove this and it will centre correctly.