Fix #110601: Line Tool crashes when object has subdivision surface

We must be very careful when using evaluated objects as their data may
not be marked as being in edit mode.

This can cause the drawing arrays and the accessed ones not to match
causing python errors and crashes due to failure to exit the drawing
matrices context.

mesh_snap_utilities_line/snap_context_l/mesh_drawing.py

@@ -113,12 +113,11 @@ def get_bmesh_loosevert_array(bm):
 
 
 class _Mesh_Arrays:
-    def __init__(self, obj, create_tris, create_edges, create_looseverts):
+    def __init__(self, depsgraph, obj, create_tris, create_edges, create_looseverts):
         self.tri_verts = self.edge_verts = self.looseverts = ()
         if obj.type == "MESH":
-            me = obj.data
-            if me.is_editmode:
-                bm = bmesh.from_edit_mesh(me)
+            if obj.data.is_editmode:
+                bm = bmesh.from_edit_mesh(obj.data)
                 bm.verts.ensure_lookup_table()
 
                 self.verts_co = get_bmesh_vert_co_array(bm)
@@ -129,11 +128,9 @@ class _Mesh_Arrays:
                     self.edge_verts = get_bmesh_edge_verts_array(bm)
                 if create_looseverts:
                     self.looseverts = get_bmesh_loosevert_array(bm)
-
-                del bm
             else:
-                import bpy
-
+                ob_eval = obj.evaluated_get(depsgraph)
+                me = ob_eval.data
                 self.verts_co = get_mesh_vert_co_array(me)
 
                 if create_tris:
@@ -175,21 +172,20 @@ class GPU_Indices_Mesh:
         "users",
     )
 
-    _Hash = {}
+    _cache = {}
     shader = None
     UBO_data = None
     UBO = None
 
     @classmethod
-    def end_opengl(cls):
+    def gpu_data_free(cls):
         del cls.shader
         del cls.UBO
         del cls.UBO_data
-
-        del cls
+        cls.shader = cls.UBO = cls.UBO_data = None
 
     @staticmethod
-    def init_opengl():
+    def gpu_data_ensure():
         cls = GPU_Indices_Mesh
         # OpenGL was already initialized, nothing to do here.
         if cls.shader is not None:
@@ -198,8 +194,8 @@ class GPU_Indices_Mesh:
         import atexit
 
         # Make sure we only registered the callback once.
-        atexit.unregister(cls.end_opengl)
-        atexit.register(cls.end_opengl)
+        atexit.unregister(cls.gpu_data_free)
+        atexit.register(cls.gpu_data_free)
 
         shader_info = gpu.types.GPUShaderCreateInfo()
 
@@ -278,8 +274,8 @@ class GPU_Indices_Mesh:
     def __init__(self, depsgraph, obj, draw_tris, draw_edges, draw_verts):
         self.ob_data = obj.original.data
 
-        if self.ob_data in GPU_Indices_Mesh._Hash:
-            src = GPU_Indices_Mesh._Hash[self.ob_data]
+        if self.ob_data in GPU_Indices_Mesh._cache:
+            src = GPU_Indices_Mesh._cache[self.ob_data]
             dst = self
 
             dst.draw_tris = src.draw_tris
@@ -296,10 +292,10 @@ class GPU_Indices_Mesh:
             dst.users.append(self)
 
             update = False
-
         else:
-            GPU_Indices_Mesh._Hash[self.ob_data] = self
+            GPU_Indices_Mesh._cache[self.ob_data] = self
             self.users = [self]
+
             update = True
 
         if update:
@@ -307,12 +303,10 @@ class GPU_Indices_Mesh:
             self.draw_edges = draw_edges
             self.draw_verts = draw_verts
 
-            GPU_Indices_Mesh.init_opengl()
+            GPU_Indices_Mesh.gpu_data_ensure()
 
             ## Init Array ##
-            mesh_arrays = _Mesh_Arrays(
-                depsgraph.id_eval_get(obj), draw_tris, draw_edges, draw_verts
-            )
+            mesh_arrays = _Mesh_Arrays(depsgraph, obj, draw_tris, draw_edges, draw_verts)
 
             if mesh_arrays.verts_co is None:
                 self.draw_tris = False
@@ -477,13 +471,13 @@ class GPU_Indices_Mesh:
             del self.tri_verts
             del self.edge_verts
             del self.looseverts
-            GPU_Indices_Mesh._Hash.pop(self.ob_data)
+            GPU_Indices_Mesh._cache.pop(self.ob_data)
 
         # print('mesh_del', self.obj.name)
 
 
 def gpu_Indices_enable_state(winmat, viewmat):
-    GPU_Indices_Mesh.init_opengl()
+    GPU_Indices_Mesh.gpu_data_ensure()
     gpu.matrix.push()
     gpu.matrix.push_projection()
     gpu.matrix.load_projection_matrix(winmat)
@@ -497,7 +491,7 @@ def gpu_Indices_restore_state():
 
 
 def gpu_Indices_use_clip_planes(rv3d, value):
-    GPU_Indices_Mesh.init_opengl()
+    GPU_Indices_Mesh.gpu_data_ensure()
     if value and rv3d.use_clip_planes:
         GPU_Indices_Mesh.UBO_data.use_clip_planes = True
         GPU_Indices_Mesh.UBO_data.WorldClipPlanes[0] = rv3d.clip_planes[0][:]
@@ -511,4 +505,4 @@ def gpu_Indices_use_clip_planes(rv3d, value):
 
 
 def gpu_Indices_mesh_cache_clear():
-    GPU_Indices_Mesh._Hash.clear()
+    GPU_Indices_Mesh._cache.clear()