code review fixes

BadSingleton · BadSingleton · commit 891ad8c93afb · 2021-03-05T13:43:24.000-05:00
diff --git a/src/runtime/exceptions.cs b/src/runtime/exceptions.cs
@@ -89,8 +89,11 @@ internal static Exception ToException(IntPtr ob)
         static void ClearOffsetHelper(IntPtr ob, int offset)
         {
             var field = Marshal.ReadIntPtr(ob, offset);
-            Runtime.XDecref(field);
-            Marshal.WriteIntPtr(ob, offset, IntPtr.Zero);
+            if (field != IntPtr.Zero)
+            {
+                Marshal.WriteIntPtr(ob, offset, IntPtr.Zero);
+                Runtime.XDecref(field);
+            }
         }
 
         // As seen in exceptions.c, every derived type must also clean the base.

Original file line number	Diff line number	Diff line change
`@@ -89,8 +89,11 @@ internal static Exception ToException(IntPtr ob)`
`89`	`89`	`static void ClearOffsetHelper(IntPtr ob, int offset)`
`90`	`90`	`{`
`91`	`91`	`var field = Marshal.ReadIntPtr(ob, offset);`
`92`		`- Runtime.XDecref(field);`
`93`		`- Marshal.WriteIntPtr(ob, offset, IntPtr.Zero);`
	`92`	`+ if (field != IntPtr.Zero)`
	`93`	`+ {`
	`94`	`+ Marshal.WriteIntPtr(ob, offset, IntPtr.Zero);`
	`95`	`+ Runtime.XDecref(field);`
	`96`	`+ }`
`94`	`97`	`}`
`95`	`98`
`96`	`99`	`// As seen in exceptions.c, every derived type must also clean the base.`