Add regression tests for vector NULL safety and uniform owner validity, closes #287

Covers #268 (sfVector2f_to_PyObject NULL propagation) and #272
(UniformCollection weak_ptr validity check). Combined with existing
tests for #258-#278, this completes regression coverage for the
full memory safety audit.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/regression/issue_268_vector_null_test.py

@@ -0,0 +1,69 @@
+"""Regression test: sfVector2f_to_PyObject must handle allocation failure.
+
+Issue #268: sfVector2f_to_PyObject in UIEntity.cpp could return NULL when
+tp_alloc fails, but callers didn't check. Under normal conditions this
+can't be triggered, but this test exercises all Vector-returning entity
+properties to ensure the code path works correctly and doesn't crash.
+
+Fix: Callers now propagate NULL returns as Python exceptions.
+"""
+import mcrfpy
+import sys
+
+def test_entity_vector_properties():
+    """All Vector-returning properties must return valid Vector objects."""
+    grid = mcrfpy.Grid(grid_size=(20, 20))
+    entity = mcrfpy.Entity(grid_pos=(5, 5), grid=grid)
+
+    pos = entity.pos
+    assert pos is not None, "entity.pos returned None"
+    assert hasattr(pos, 'x') and hasattr(pos, 'y'), "pos missing x/y"
+
+    draw_pos = entity.draw_pos
+    assert draw_pos is not None, "entity.draw_pos returned None"
+
+    cell_pos = entity.cell_pos
+    assert cell_pos is not None, "entity.cell_pos returned None"
+    assert cell_pos.x == 5 and cell_pos.y == 5, f"cell_pos wrong: {cell_pos.x}, {cell_pos.y}"
+
+    offset = entity.sprite_offset
+    assert offset is not None, "entity.sprite_offset returned None"
+    assert offset.x == 0.0 and offset.y == 0.0, "Default sprite_offset should be (0,0)"
+
+    print("  PASS: entity vector properties")
+
+def test_entity_vector_setters():
+    """Vector property setters must accept tuples and Vectors."""
+    grid = mcrfpy.Grid(grid_size=(20, 20))
+    entity = mcrfpy.Entity(grid_pos=(3, 3), grid=grid)
+
+    entity.sprite_offset = (10.0, -5.0)
+    assert entity.sprite_offset.x == 10.0, f"sprite_offset.x wrong: {entity.sprite_offset.x}"
+    assert entity.sprite_offset.y == -5.0, f"sprite_offset.y wrong: {entity.sprite_offset.y}"
+
+    entity.draw_pos = mcrfpy.Vector(7.5, 8.5)
+    assert entity.draw_pos.x == 7.5, f"draw_pos.x wrong: {entity.draw_pos.x}"
+
+    print("  PASS: entity vector setters")
+
+def test_entity_no_grid_vector():
+    """Entities without a grid should handle vector properties gracefully."""
+    entity = mcrfpy.Entity()
+
+    draw_pos = entity.draw_pos
+    assert draw_pos is not None, "draw_pos should work without grid"
+
+    cell_pos = entity.cell_pos
+    assert cell_pos is not None, "cell_pos should work without grid"
+
+    offset = entity.sprite_offset
+    assert offset is not None, "sprite_offset should work without grid"
+
+    print("  PASS: entity no-grid vector properties")
+
+print("Testing issue #268: sfVector2f_to_PyObject NULL safety...")
+test_entity_vector_properties()
+test_entity_vector_setters()
+test_entity_no_grid_vector()
+print("All #268 tests passed.")
+sys.exit(0)

tests/regression/issue_272_uniform_owner_test.py

@@ -0,0 +1,90 @@
+"""Regression test: UniformCollection must check owner validity.
+
+Issue #272: PyUniformCollectionObject stored a raw pointer to UniformCollection
+but only checked non-NULL. If the owning UIDrawable was destroyed, the raw
+pointer dangled, causing use-after-free.
+
+Fix: Added weak_ptr<void> owner field. All accessors now check owner.lock()
+before accessing the collection, raising RuntimeError if the owner is gone.
+"""
+import mcrfpy
+import gc
+import sys
+
+def test_uniforms_basic_access():
+    """Uniform collection should work when owner is alive."""
+    frame = mcrfpy.Frame(pos=(0, 0), size=(100, 100))
+    u = frame.uniforms
+    assert len(u) == 0, f"Expected empty uniforms, got {len(u)}"
+
+    u['brightness'] = 1.0
+    assert len(u) == 1, f"Expected 1 uniform, got {len(u)}"
+    assert 'brightness' in u, "brightness should be in uniforms"
+
+    del u['brightness']
+    assert len(u) == 0, f"Expected 0 after delete, got {len(u)}"
+
+    print("  PASS: basic uniform access")
+
+def test_uniforms_owner_destroyed():
+    """Accessing uniforms after owner destruction must fail gracefully."""
+    frame = mcrfpy.Frame(pos=(0, 0), size=(100, 100))
+    u = frame.uniforms
+    u['test'] = 1.0
+
+    del frame
+    gc.collect()
+
+    # len() and __contains__ return 0/False gracefully
+    assert len(u) == 0, f"len should be 0 after owner destroyed, got {len(u)}"
+    assert 'test' not in u, "'test' should not be found after owner destroyed"
+
+    # Subscript access and assignment raise RuntimeError
+    errors = 0
+    try:
+        _ = u['test']
+    except RuntimeError:
+        errors += 1
+
+    try:
+        u['new'] = 2.0
+    except RuntimeError:
+        errors += 1
+
+    assert errors == 2, f"Expected 2 RuntimeErrors from subscript ops, got {errors}"
+    print("  PASS: uniforms after owner destroyed")
+
+def test_uniforms_owner_in_scene():
+    """Uniforms should work while owner is in a scene's children."""
+    scene = mcrfpy.Scene("uniform_test")
+    frame = mcrfpy.Frame(pos=(0, 0), size=(100, 100))
+    scene.children.append(frame)
+    u = frame.uniforms
+    u['value'] = 0.5
+    assert len(u) == 1, "Uniform should be accessible while in scene"
+    print("  PASS: uniforms with scene-owned frame")
+
+def test_uniforms_multiple_values():
+    """Multiple uniform types should work correctly."""
+    frame = mcrfpy.Frame(pos=(0, 0), size=(100, 100))
+    u = frame.uniforms
+
+    u['f'] = 1.0
+    u['v2'] = (1.0, 2.0)
+    u['v3'] = (1.0, 2.0, 3.0)
+    u['v4'] = (1.0, 2.0, 3.0, 4.0)
+
+    assert len(u) == 4, f"Expected 4 uniforms, got {len(u)}"
+
+    keys = list(u.keys())
+    assert len(keys) == 4, f"Expected 4 keys, got {len(keys)}"
+
+    print("  PASS: multiple uniform types")
+
+print("Testing issue #272: UniformCollection owner validity...")
+test_uniforms_basic_access()
+test_uniforms_owner_destroyed()
+test_uniforms_owner_in_scene()
+test_uniforms_multiple_values()
+print("All #272 tests passed.")
+sys.exit(0)