From d0c7b427ff08811e3fe69a596ea459bc8a0abbd1 Mon Sep 17 00:00:00 2001
From: marcuspollio <131592747+marcuspollio@users.noreply.github.com>
Date: Tue, 14 Oct 2025 11:19:43 +0200
Subject: [PATCH] BIM: Prevent crash when removing a wall's base component
 (#24633)

* BIM: Prevent crash when removing a wall's base component

When a user selected a wall's base object in the Tree View and used the
`Arch_Remove` command, a traceback occurred due to an `AttributeError`.

The `removeComponents` function was incorrectly checking for the `.Base`
attribute on a list of subtractions (`s.Base`) instead of on the parent
host object (`h.Base`).

This commit corrects the reference to check against the parent object,
resolving the crash and allowing the component to be removed.

Fixes: https://github.com/FreeCAD/FreeCAD/issues/24532

Authored-by:  furgo16 <148809153+furgo16@users.noreply.github.com>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: Furgo <148809153+furgo16@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 src/Mod/BIM/ArchCommands.py          |  7 ++++---
 src/Mod/BIM/bimtests/TestArchWall.py | 23 +++++++++++++++++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/Mod/BIM/ArchCommands.py b/src/Mod/BIM/ArchCommands.py
index 4bd2a12497..0a034a1665 100644
--- a/src/Mod/BIM/ArchCommands.py
+++ b/src/Mod/BIM/ArchCommands.py
@@ -263,9 +263,10 @@ def removeComponents(objectsList, host=None):
                         s.remove(o)
                         h.Subtractions = s
                         o.ViewObject.show()
-                    elif o == s.Base:
-                        s.Base = None
-                        o.ViewObject.show()
+                    elif o == h.Base:
+                        h.Base = None
+                        if FreeCAD.GuiUp:
+                            o.ViewObject.show()
                 elif tp in ["SectionPlane"]:
                     a = h.Objects
                     if o in a:
diff --git a/src/Mod/BIM/bimtests/TestArchWall.py b/src/Mod/BIM/bimtests/TestArchWall.py
index 3bb8429554..30a323f58f 100644
--- a/src/Mod/BIM/bimtests/TestArchWall.py
+++ b/src/Mod/BIM/bimtests/TestArchWall.py
@@ -115,3 +115,26 @@ class TestArchWall(TestArchBase.TestArchBase):
         wall2 = Arch.makeWall(base_line2, width=200, height=3000)
         joined_wall = Arch.joinWalls([wall1, wall2])
         self.assertIsNotNone(joined_wall, "joinWalls failed to join walls.")
+
+    def test_remove_base_from_wall_without_host(self):
+        """
+        Tests that removing a wall's base using removeComponents(host=None)
+        does not crash and successfully unlinks the base.
+        This is the non-regression test for the 'list' has no attribute 'Base' bug.
+        https://github.com/FreeCAD/FreeCAD/issues/24532
+        """
+        self.printTestMessage("Testing removal of a wall's base component...")
+
+        # 1. Arrange: Create a wall with a base
+        line = Draft.makeLine(App.Vector(0, 0, 0), App.Vector(2000, 0, 0))
+        wall = Arch.makeWall(line)
+        self.assertIsNotNone(wall.Base, "Pre-condition failed: Wall should have a base.")
+
+        # 2. Act: Call removeComponents on the base, simulating the failing workflow
+        # Before the fix, this will raise an AttributeError.
+        # After the fix, it should complete without error.
+        Arch.removeComponents([wall.Base])
+        self.document.recompute()
+
+        # 3. Assert: The base should now be None
+        self.assertIsNone(wall.Base, "The wall's Base property was not cleared after removal.")