From fe1fe5b1142a4b0a26ecef628f3eaccf4a2d4372 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Tue, 30 Apr 2024 15:21:49 +0300
Subject: [PATCH] gstreamer: Use a reference to a pointer of correct mutability
 for from_glib_ptr_borrow()

This hopefully makes it easier to use and harder to get the returned
lifetime wrong.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1436>
---
 gstreamer/src/miniobject.rs | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/gstreamer/src/miniobject.rs b/gstreamer/src/miniobject.rs
index 4bc8e6481..1b859a10f 100644
--- a/gstreamer/src/miniobject.rs
+++ b/gstreamer/src/miniobject.rs
@@ -30,10 +30,12 @@ macro_rules! mini_object_wrapper (
 
         impl $name {
             #[inline]
-            pub unsafe fn from_glib_ptr_borrow<'a>(
-                ptr: *const *const $ffi_name,
-            ) -> &'a Self {
-                &*(ptr as *const $name)
+            pub unsafe fn from_glib_ptr_borrow(
+                ptr: &*mut $ffi_name,
+            ) -> &Self {
+                debug_assert_eq!(std::mem::size_of::<$name>(), std::mem::size_of::<$crate::glib::ffi::gpointer>());
+                debug_assert!(!ptr.is_null());
+                &*(ptr as *const *mut $ffi_name as *const $name)
             }
 
             #[inline]
@@ -548,11 +550,8 @@ macro_rules! mini_object_wrapper (
             #[inline]
             unsafe fn from_value(value: &'a $crate::glib::Value) -> Self {
                 skip_assert_initialized!();
-                assert_eq!(std::mem::size_of::<$name>(), std::mem::size_of::<$crate::glib::ffi::gpointer>());
                 let value = &*(value as *const $crate::glib::Value as *const $crate::glib::gobject_ffi::GValue);
-                let ptr = &value.data[0].v_pointer as *const $crate::glib::ffi::gpointer as *const *const $ffi_name;
-                debug_assert!(!(*ptr).is_null());
-                &*(ptr as *const $name)
+                $name::from_glib_ptr_borrow(&*(&value.data[0].v_pointer as *const $crate::glib::ffi::gpointer as *const *mut $ffi_name))
             }
         }