mshtml: Return E_POINTER when p is NULL in get_nsstyle_pixel_val.

dlls/mshtml/htmlstyle.c

@@ -684,6 +684,9 @@ static HRESULT get_nsstyle_pixel_val(HTMLStyle *This, styleid_t sid, LONG *p)
     nsAString str_value;
     HRESULT hres;
 
+    if(!p)
+        return E_POINTER;
+
     nsAString_Init(&str_value, NULL);
 
     hres = get_nsstyle_attr_nsval(This->nsstyle, sid, &str_value);

dlls/mshtml/tests/style.c

@@ -1164,6 +1164,9 @@ static void test_body_style(IHTMLStyle *style)
     ok(hres == S_OK, "get_pixelLeft failed: %08x\n", hres);
     ok(l == 6, "pixelLeft = %d\n", l);
 
+    hres = IHTMLStyle_get_pixelLeft(style, NULL);
+    ok(hres == E_POINTER, "get_pixelLeft failed: %08x\n", hres);
+
     V_VT(&v) = VT_EMPTY;
     hres = IHTMLStyle_get_left(style, &v);
     ok(hres == S_OK, "get_left failed: %08x\n", hres);