Fixed crash due to unnecessary decref of a borrowed reference in params array handling (pythonnet#1163)

lostmsu · filmor · commit b85104b97d6a · 2020-06-18T08:33:33.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,7 +13,8 @@ This document follows the conventions laid out in [Keep a CHANGELOG][].
 
 ### Fixed
 
--    Fix incorrect dereference of wrapper object in tp_repr, which may result in a program crash
+-    Fix incorrect dereference of wrapper object in `tp_repr`, which may result in a program crash
+-    Fix incorrect dereference in params array handling
 
 ## [2.5.0][] - 2020-06-14
 
diff --git a/src/runtime/methodbinder.cs b/src/runtime/methodbinder.cs
@@ -372,7 +372,7 @@ internal Binding Bind(IntPtr inst, IntPtr args, IntPtr kw, MethodBase info, Meth
         static IntPtr HandleParamsArray(IntPtr args, int arrayStart, int pyArgCount, out bool isNewReference)
         {
             isNewReference = false;
-            IntPtr op;
+            IntPtr op;
             // for a params method, we may have a sequence or single/multiple items
             // here we look to see if the item at the paramIndex is there or not
             // and then if it is a sequence itself.
@@ -390,10 +390,6 @@ static IntPtr HandleParamsArray(IntPtr args, int arrayStart, int pyArgCount, out
                 {
                     isNewReference = true;
                     op = Runtime.PyTuple_GetSlice(args, arrayStart, pyArgCount);
-                    if (item != IntPtr.Zero)
-                    {
-                        Runtime.XDecref(item);
-                    }
                 }
             }
             else

Original file line number	Diff line number	Diff line change
`@@ -372,7 +372,7 @@ internal Binding Bind(IntPtr inst, IntPtr args, IntPtr kw, MethodBase info, Meth`
`372`	`372`	`static IntPtr HandleParamsArray(IntPtr args, int arrayStart, int pyArgCount, out bool isNewReference)`
`373`	`373`	`{`
`374`	`374`	`isNewReference = false;`
`375`		`- IntPtr op;`
	`375`	`+ IntPtr op;`
`376`	`376`	`// for a params method, we may have a sequence or single/multiple items`
`377`	`377`	`// here we look to see if the item at the paramIndex is there or not`
`378`	`378`	`// and then if it is a sequence itself.`
`@@ -390,10 +390,6 @@ static IntPtr HandleParamsArray(IntPtr args, int arrayStart, int pyArgCount, out`
`390`	`390`	`{`
`391`	`391`	`isNewReference = true;`
`392`	`392`	`op = Runtime.PyTuple_GetSlice(args, arrayStart, pyArgCount);`
`393`		`- if (item != IntPtr.Zero)`
`394`		`- {`
`395`		`- Runtime.XDecref(item);`
`396`		`- }`
`397`	`393`	`}`
`398`	`394`	`}`
`399`	`395`	`else`