null terminate the converted LPStr at the right index (dotnet/coreclr…

…#17079) Commit migrated from dotnet/coreclr@e99c94d
shadow-cs · Mar 21, 2018 · 5929b34 · 5929b34
1 parent d4500ee
commit 5929b34
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/src/coreclr/src/vm/olevariant.cpp b/src/coreclr/src/vm/olevariant.cpp
@@ -2310,8 +2310,9 @@ void OleVariant::MarshalLPSTRRArrayComToOle(BASEARRAYREF *pComArray, void *oleAr
                 ThrowOutOfMemory();
 
             // Convert the unicode string to an ansi string.
-            InternalWideToAnsi(stringRef->GetBuffer(), Length, lpstr, allocLength, fBestFitMapping, fThrowOnUnmappableChar);
-            lpstr[Length] = 0;
+            int bytesWritten = InternalWideToAnsi(stringRef->GetBuffer(), Length, lpstr, allocLength, fBestFitMapping, fThrowOnUnmappableChar);
+            _ASSERTE(bytesWritten >= 0 && bytesWritten < allocLength);
+            lpstr[bytesWritten] = 0;
         }
 
         *pOle++ = lpstr;