[Ak4shh]

Fixes #3467.

The bug

PageObject.merge_page() clones the annotations of the page passed to it.
DictionaryObject.clone() built the clone target with self.__class__(),
which is impossible for every annotation class, because their constructors
require arguments:

TypeError: Polygon.__init__() missing 1 required positional argument: 'vertices'

The same self.__class__() call was in DictionaryObject.replicate(), so this
affected any clone/replicate of an annotation dictionary, not just
merge_page.

The fix

DictionaryObject._new_for_clone() creates the empty target. When the class
cannot be instantiated without arguments, it instantiates it without calling
__init__; the clone is populated from the source object immediately
afterwards, so the constructor arguments are not needed. Annotation
constructors only store their arguments in the dictionary anyway
(self["/Vertices"] = ...), which _clone then copies from the source.

The check is signature-based (and cached per class) rather than
try/except TypeError, because Link() raises ValueError when neither
url nor target_page_index is given.

Classes that can be built without arguments (e.g. PageObject, which sets
pdf in __init__) keep taking the normal construction path.

Tests

• tests/test_page.py::test_merge_page_with_annotations_of_merged_page — the
  issue's reproducer: merge a page that carries a Polygon annotation, then
  assert the annotation survives a write/re-read round trip.
• tests/test_annotations.py::test_clone_and_replicate_annotation —
  parametrized over all ten annotation classes (Ellipse, FreeText,
  Highlight, Line, Link, Polygon, PolyLine, Popup, Rectangle,
  Text), asserting that clone() and replicate() both return the same
  class with the same keys and that the copy does not share entries with the
  source.

Both tests fail on main and pass with this change:

# without the fix
TypeError: Ellipse.__init__() missing 1 required positional argument: 'rect'
TypeError: FreeText.__init__() missing 2 required keyword-only arguments: ...
TypeError: Highlight.__init__() missing 2 required keyword-only arguments: ...
TypeError: Line.__init__() missing 3 required positional arguments: ...

Full suite

python -m pytest tests -q --basetemp=... on Windows / Python 3.13:
31 failed, 2158 passed, 34 skipped, 95 errors — identical failures and errors
to the unmodified tree (all pre-existing and environmental: empty
sample-files/ submodule, missing fontTools, pytest-cache/tmp_path
permission issues). passed rises by exactly the 11 new test cases.

Scope

Three files: pypdf/generic/_data_structures.py, tests/test_annotations.py,
tests/test_page.py.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.67%. Comparing base (9c4a693) to head (7d3deae).
⚠️ Report is 15 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4262      +/-   ##
==========================================
+ Coverage   98.40%   98.67%   +0.26%     
==========================================
  Files          59       59              
  Lines       11992    11967      -25     
  Branches     2267     2268       +1     
==========================================
+ Hits        11801    11808       +7     
+ Misses        104       84      -20     
+ Partials       87       75      -12     

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[stefan6419846]

Why not .items()?

[Ak4shh]

Removed it - inspect.signature only raises for C-level builtins like type, never a Python init, so it was dead code.Updated to compare .items() so the assertion checks both keys and values.

[stefan6419846]

The old behavior is irrelevant in the test docstrings.

[Ak4shh]

Removed the historical behavior from both test docstrings. They now describe the behavior being tested.

[Ak4shh]

Removed the try/except around inspect.signature(). A Python-level init never triggers it, so it was dead code.
The annotation test now compares .items(), so values are checked as well as keys.
The test docstrings now describe only the behavior under test, not the old behavior.

[Ak4shh]

Addressed all three points, and also fixed cloning of linked /Next//Prev//N//V objects (with a test). Could you take another look?