compiler: Fix infinite recursion trying to inline function argument

We can't use `body.visit_recursive_mut` because it will recurse on the
newly replaced argument. Implement recursion manually instead.

Author: ogoffart

internal/compiler/passes/const_propagation.rs

@@ -263,14 +263,17 @@ fn try_inline_function(function: &Callable, arguments: &[Expression]) -> Option<
     }
     let mut body = extract_constant_property_reference(function)?;
 
-    body.visit_recursive_mut(&mut |e| {
+    fn substitute_arguments_recursive(e: &mut Expression, arguments: &[Expression]) {
         if let Expression::FunctionParameterReference { index, ty } = e {
-            let Some(e_new) = arguments.get(*index).cloned() else { return };
-            if e_new.ty() == *ty {
-                *e = e_new;
-            }
+            let e_new = arguments.get(*index).expect("reference to invalid arg").clone();
+            debug_assert_eq!(e_new.ty(), *ty);
+            *e = e_new;
+        } else {
+            e.visit_mut(|e| substitute_arguments_recursive(e, arguments));
         }
-    });
+    }
+    substitute_arguments_recursive(&mut body, arguments);
+
     if simplify_expression(&mut body) {
         Some(body)
     } else {

tests/cases/issues/issue_7811_inline_stack_overflow.slint

@@ -0,0 +1,43 @@
+// Copyright © SixtyFPS GmbH <[email protected]>
+// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
+
+struct Structure {
+    value: int,
+}
+
+component AlignedValue {
+    in property <int> alignment: 1;
+    in-out property <int> aligned-value;
+    pure function align(value: int) -> int {
+        (value / alignment) * alignment
+    }
+    public function set-value(new-value: int) {
+        aligned-value = align(Math.max(0, new-value));
+    }
+}
+
+export component TestCase inherits Window {
+    in-out property <Structure> range: { value: 42 };
+    checked-range := AlignedValue {
+        aligned-value: range.value;
+    }
+
+    init => {
+        checked-range.set_value(78);
+    }
+
+    out property <bool> test: checked-range.aligned-value == 78;
+}
+
+/*
+```cpp
+auto handle = TestCase::create();
+const TestCase &instance = *handle;
+assert(instance.get_test());
+```
+
+```rust
+let instance = TestCase::new().unwrap();
+assert!(instance.get_test());
+```
+*/