[RavSinghChandan]

Adobe Illustrator writes every clip path like this, next to the elements it clips rather than in <defs>:

<g>
  <defs><rect id="SVGID_1_" width="50" height="50"/></defs>
  <clipPath id="SVGID_2_"><use xlink:href="#SVGID_1_" overflow="visible"/></clipPath>
  <path clip-path="url(#SVGID_2_)" d="..."/>
</g>

fpdf2 ignores both the <clipPath> outside <defs> ("Ignoring unsupported SVG tag: ") and the <use> inside it ("Ignoring unsupported child tag: "), so the clip path is never registered and every element that uses it fails with KeyError: '#SVGID_2_'. The six file-type icons in PyMuPDF's documentation (docs/images/icons/icon-pdf.svg etc.) all fail this way.

• A <clipPath> found among the children of a group is now handled like one in <defs> (the shared code moved to build_clip_path_tag()); it is never rendered directly.
• A <use> in a <clipPath> now adds the shape or path it references, with its x/y and transform applied as SVG specifies (translate(x, y) first, like build_xref() does). A <use> that references another <use> or a group is still ignored with a warning: the spec only allows shapes, text and paths there.

The six PyMuPDF icons render correctly with this change (checked visually).

Added test_svg_clip_path_outside_defs, test_svg_clip_path_with_use, test_svg_clip_path_with_use_placement and test_svg_clip_path_unsupported_child; the first three fail on master, and the new code is fully covered. pytest test/svg test/drawing, black, pylint and mypy pass

[andersonhc]

pylint is failint:

************* Module test.svg.test_svg
test/svg/test_svg.py:324:0: W1404: Implicit string concatenation found in list (implicit-str-concat)
test/svg/test_svg.py:326:0: W1404: Implicit string concatenation found in list (implicit-str-concat)

[RavSinghChandan]

Thanks, fixed: the concatenated strings in that parametrize list are now in parentheses, and pylint passes on the test file. I also rebased on master.

[andersonhc]

When references a , this helper returns a PaintedPath rather than a ClippingPath