jscript: Return array length in Array.unshift for invoke version >= 2.

dlls/jscript/array.c

@@ -967,12 +967,7 @@ static HRESULT Array_unshift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISP
         return hres;
 
     argc = arg_cnt(dp);
-    if(!argc) {
-        if(retv)
-            V_VT(retv) = VT_EMPTY;
-        return S_OK;
-    }
-
+    if(argc) {
         buf_end = buf + sizeof(buf)/sizeof(WCHAR)-1;
         *buf_end-- = 0;
         i = length;
@@ -991,6 +986,7 @@ static HRESULT Array_unshift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISP
             }else if(hres == DISP_E_UNKNOWNNAME) {
                 hres = IDispatchEx_DeleteMemberByDispID(vthis->u.dispex, id);
             }
+        }
 
         if(FAILED(hres))
             return hres;
@@ -1002,12 +998,21 @@ static HRESULT Array_unshift(script_ctx_t *ctx, vdisp_t *vthis, WORD flags, DISP
             return hres;
     }
 
-    hres = set_length(jsthis, ei, length+argc);
+    if(argc) {
+        length += argc;
+        hres = set_length(jsthis, ei, length);
         if(FAILED(hres))
             return hres;
+    }
 
-    if(retv)
+    if(retv) {
+        if(ctx->version < 2) {
             V_VT(retv) = VT_EMPTY;
+        }else {
+            V_VT(retv) = VT_I4;
+            V_I4(retv) = length;
+        }
+    }
     return S_OK;
 }