Fix use-after-free in XConnection::get_output_info (#1211)

CHANGELOG.md

@@ -26,6 +26,7 @@
 - Removed `derivative` crate dependency.
 - On Wayland, add support for set_cursor_icon.
 - Use `impl Iterator<Item = MonitorHandle>` instead of `AvailableMonitorsIter` consistently.
+- On X11, fix use-after-free during window creation
 
 # 0.20.0 Alpha 3 (2019-08-14)
 

src/platform_impl/linux/x11/util/randr.rs

@@ -99,7 +99,8 @@ impl XConnection {
                     // video mode is returned to the user
                     monitor: None,
                 }
-            });
+            })
+            .collect();
 
         let name_slice = slice::from_raw_parts(
             (*output_info).name as *mut u8,
@@ -119,7 +120,7 @@ impl XConnection {
         };
 
         (self.xrandr.XRRFreeOutputInfo)(output_info);
-        Some((name, hidpi_factor, modes.collect()))
+        Some((name, hidpi_factor, modes))
     }
     pub fn set_crtc_config(&self, crtc_id: RRCrtc, mode_id: RRMode) -> Result<(), ()> {
         unsafe {