Property `clip-path:polygon()` with reference box causes warning
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- Dominant language
- Java
- Stars
- 250
- Forks
- 123
- PR merge metrics
- No merged PRs in 30d
Description
When validating CSS that uses the clip-path:polygon() property together with a value for the reference box like margin-box, border-box, padding-box or content-box as described by MDN, it passes the validator at https://jigsaw.w3.org/css-validator/ but yields a warning, stating:
"Too many values or values not identified." (translated from German message)
Full example: clip-path: margin-box polygon(20% 0%, 100% 50%, 80% 100%, 0% 50%);
I think, this property should not yield any warning, or is there a reason for this?
Thanks!
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reproducing the warning in the W3C CSS Validator with clip-path: margin-box polygon(20% 0%, 100% 50%, 80% 100%, 0% 50%);. Trace how the validator parses clip-path values with reference boxes, then verify that valid combinations no longer produce the warning.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- css, java
- Domain
- tooling, web-dev
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100