CI for memory safety - updates

tests/test_gridstate_resize.py

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+"""Regression test: entity gridstate must resize when moving between grids.
+
+Bug: UIEntity::set_grid() only initialized gridstate when it was empty
+(size == 0). When an entity moved from a small grid to a larger grid,
+gridstate kept the old size. UIEntity::updateVisibility() then wrote
+past the end of the vector using the new grid's dimensions, corrupting
+adjacent heap memory.
+
+Trigger: any entity that calls update_visibility() after moving to a
+larger grid. In Liber Noster this was the player entity using the
+engine's perspective FOV system across zone transitions.
+
+This script should exit cleanly. Before the fix, it segfaulted or
+produced incorrect gridstate lengths.
+"""
+import mcrfpy
+
+# Create a small grid and a large grid
+small = mcrfpy.Grid(grid_size=(10, 10))
+large = mcrfpy.Grid(grid_size=(50, 50))
+
+# Create an entity on the small grid
+entity = mcrfpy.Entity(grid_pos=(5, 5), grid=small)
+
+# Force gridstate initialization by calling update_visibility
+small.perspective = entity
+small.fov_radius = 4
+entity.update_visibility()  # gridstate sized to 10*10 = 100
+
+# Verify gridstate matches small grid
+gs = entity.gridstate
+assert len(gs) == 100, f"Expected gridstate size 100 for 10x10 grid, got {len(gs)}"
+
+# Move entity to the larger grid
+entity.grid = large
+
+# Gridstate must now match the large grid's dimensions
+gs = entity.gridstate
+assert len(gs) == 2500, f"Expected gridstate size 2500 for 50x50 grid, got {len(gs)}"
+
+# Set up perspective on the large grid
+large.perspective = entity
+large.fov_radius = 8
+
+# This triggers updateVisibility() which iterates 50*50 = 2500 cells.
+# Before the fix, gridstate was only 100 entries — heap buffer overflow.
+entity.update_visibility()
+
+# Stress test: repeatedly move between grids of different sizes to
+# exercise the resize path and pressure the heap allocator.
+grids = [mcrfpy.Grid(grid_size=(s, s)) for s in (5, 80, 3, 60, 10, 100)]
+for g in grids:
+    entity.grid = g
+    g.perspective = entity
+    g.fov_radius = 4
+    entity.update_visibility()
+    gs = entity.gridstate
+    expected = g.grid_w * g.grid_h
+    assert len(gs) == expected, f"Expected {expected}, got {len(gs)} for {g.grid_w}x{g.grid_h}"
+
+# Also allocate other objects between transitions to fill freed heap
+# regions — makes corruption more likely to manifest as a crash.
+for i in range(20):
+    small_g = mcrfpy.Grid(grid_size=(5, 5))
+    entity.grid = small_g
+    small_g.perspective = entity
+    entity.update_visibility()
+
+    big_g = mcrfpy.Grid(grid_size=(80, 80))
+    entity.grid = big_g
+    big_g.perspective = entity
+    entity.update_visibility()
+
+    # Create and destroy interim objects to churn the heap
+    frames = [mcrfpy.Frame() for _ in range(10)]
+    del frames
+
+print("PASS: gridstate resized correctly across all transitions")