From b9307ca2582706519abf487175c3c0ddbf2e4654 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Sun, 10 Dec 2023 20:18:54 +0200
Subject: [PATCH] gstreamer: memory: Fix assertions for copy_range/resize/share
 functions

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1392>
---
 gstreamer/src/memory.rs | 43 +++++++++++++++++++++++++++++++----------
 1 file changed, 33 insertions(+), 10 deletions(-)

diff --git a/gstreamer/src/memory.rs b/gstreamer/src/memory.rs
index 714189ac1..bc7dbf27b 100644
--- a/gstreamer/src/memory.rs
+++ b/gstreamer/src/memory.rs
@@ -207,12 +207,19 @@ impl MemoryRef {
         unsafe { from_glib(self.0.mini_object.flags) }
     }
 
-    pub fn copy_part(&self, offset: isize, size: Option<usize>) -> Memory {
-        let pos_sz = match size {
-            Some(val) => val as isize,
-            None => 0,
+    #[doc(alias = "gst_memory_copy")]
+    pub fn copy_range(&self, offset: isize, size: Option<usize>) -> Memory {
+        let new_offset = if offset < 0 {
+            assert!((-offset) as usize >= self.offset());
+            self.offset() - (-offset as usize)
+        } else {
+            self.offset()
+                .checked_add(offset as usize)
+                .expect("Too large offset")
         };
-        assert!(offset + pos_sz < (self.maxsize() as isize));
+
+        assert!(new_offset + size.unwrap_or(0) < self.maxsize());
+
         unsafe {
             from_glib_full(ffi::gst_memory_copy(
                 self.as_mut_ptr(),
@@ -291,11 +298,17 @@ impl MemoryRef {
 
     #[doc(alias = "gst_memory_share")]
     pub fn share(&self, offset: isize, size: Option<usize>) -> Memory {
-        let pos_sz = match size {
-            Some(val) => val as isize,
-            None => 0,
+        let new_offset = if offset < 0 {
+            assert!((-offset) as usize >= self.offset());
+            self.offset() - (-offset as usize)
+        } else {
+            self.offset()
+                .checked_add(offset as usize)
+                .expect("Too large offset")
         };
-        assert!(offset + pos_sz < (self.maxsize() as isize));
+
+        assert!(new_offset + size.unwrap_or(0) < self.maxsize());
+
         unsafe {
             from_glib_full(ffi::gst_memory_share(
                 self.as_ptr() as *mut _,
@@ -310,7 +323,17 @@ impl MemoryRef {
 
     #[doc(alias = "gst_memory_resize")]
     pub fn resize(&mut self, offset: isize, size: usize) {
-        assert!(offset + (size as isize) < (self.maxsize() as isize));
+        let new_offset = if offset < 0 {
+            assert!((-offset) as usize >= self.offset());
+            self.offset() - (-offset as usize)
+        } else {
+            self.offset()
+                .checked_add(offset as usize)
+                .expect("Too large offset")
+        };
+
+        assert!(new_offset + size < self.maxsize());
+
         unsafe { ffi::gst_memory_resize(self.as_mut_ptr(), offset, size) }
     }