Fix layout property set in when deriving components

The layout pass needs to see when going over the layout, that these
properties are set. So inline the element that sets these properties if
they are not set in the base.

Fixes #8091

internal/compiler/layout.rs

@@ -573,3 +573,14 @@ pub fn create_new_prop(elem: &ElementRc, tentative_name: SmolStr, ty: Type) -> N
         }
     }
 }
+
+/// Return true if this type is a layout that has constraints
+pub fn is_layout(base_type: &ElementType) -> bool {
+    match base_type {
+        ElementType::Component(c) => is_layout(&c.root_element.borrow().base_type),
+        ElementType::Builtin(be) => {
+            matches!(be.name.as_str(), "GridLayout" | "HorizontalLayout" | "VerticalLayout")
+        }
+        _ => false,
+    }
+}

internal/compiler/passes/flickable.rs

@@ -12,6 +12,7 @@
 
 use crate::expression_tree::{BindingExpression, Expression, MinMaxOp, NamedReference};
 use crate::langtype::{ElementType, NativeClass, Type};
+use crate::layout::is_layout;
 use crate::object_tree::{Component, Element, ElementRc};
 use crate::typeregister::TypeRegister;
 use core::cell::RefCell;
@@ -208,15 +209,6 @@ fn fixup_geometry(flickable_elem: &ElementRc) {
     });
 }
 
-/// Return true if this type is a layout that has constraints
-fn is_layout(base_type: &ElementType) -> bool {
-    if let ElementType::Builtin(be) = base_type {
-        matches!(be.name.as_str(), "GridLayout" | "HorizontalLayout" | "VerticalLayout")
-    } else {
-        false
-    }
-}
-
 /// Set the property binding on the given element to the given expression (computed lazily).
 /// The parameter to the lazily calculation is the element's children
 fn set_binding_if_not_explicit(

internal/compiler/passes/inlining.rs

@@ -644,6 +644,22 @@ fn element_require_inlining(elem: &ElementRc) -> bool {
             return true;
         }
 
+        if prop == "padding"
+            || prop == "spacing"
+            || prop.starts_with("padding-")
+            || prop.starts_with("spacing-")
+            || prop == "alignment"
+        {
+            if let ElementType::Component(base) = &elem.borrow().base_type {
+                if crate::layout::is_layout(&base.root_element.borrow().base_type) {
+                    if !base.root_element.borrow().is_binding_set(prop, false) {
+                        // The layout pass need to know that this property is set
+                        return true;
+                    }
+                }
+            }
+        }
+
         let binding = binding.borrow();
         if binding.animation.is_some() && matches!(binding.expression, Expression::Invalid) {
             // If there is an animation but no binding, we must merge the binding with its animation.

tests/cases/layout/issue8091_overriden_padding.slint

@@ -0,0 +1,51 @@
+// Copyright © SixtyFPS GmbH <info@slint.dev>
+// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
+
+// ISSUE #8091
+
+component TopBar inherits VerticalLayout {
+    // padding: 0;  // uncommenting this line make it work
+    height: 56px;
+    ir := Rectangle {
+        background: red;
+
+    }
+    out property <int> ir_h: ir.height / 1px;
+}
+
+export component TestCase inherits Window {
+    preferred-height: 380px;
+    preferred-width: 230px;
+    background: blue;
+    VerticalLayout {
+        tb := TopBar {
+            padding: 16px;
+        }
+
+        Rectangle {
+            background: black;
+        }
+    }
+
+    out property <bool> test: tb.ir_h == 24;
+}
+
+/*
+
+```rust
+let instance = TestCase::new().unwrap();
+assert!(instance.get_test());
+```
+
+```cpp
+auto handle = TestCase::create();
+const TestCase &instance = *handle;
+assert(instance.get_test());
+```
+
+```js
+var instance = new slint.TestCase();
+assert(instance.test);
+```
+
+*/