From 43592c84d4dbfd170f7f29819e3a760b89626e80 Mon Sep 17 00:00:00 2001
From: Tomas Janousek <tomi@nomi.cz>
Date: Mon, 15 Feb 2021 17:07:21 +0000
Subject: [PATCH] X.L.TrackFloating: Fix changing focus on inactive workspaces
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When focus changes¹ on an inactive workspace (not `current`, but
`visible`), TrackFloating and UseTransientFor would think they should
use the remembered focus point as they look at the wrong (`current`)
workspace instead of the workspace they're supposed to layout, and so
focus seems to be out of their set of windows, when actually it is not.

Fix this by looking at the correct workspace.

¹) This isn't entirely straightforward, as there are normally no
   keybindings or StackSet operations for this, but it's perfectly legal
   to `W.view` the inactive workspace, change focus, and `W.view` back
   in a single `windows` action.
---
 CHANGES.md                     | 4 ++++
 XMonad/Layout/TrackFloating.hs | 4 ++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index f7a4c2a4..b3feb884 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -407,6 +407,10 @@
     - Fixed handling of floating window borders in multihead setups that was
       broken since 0.14.
 
+  * `XMonad.Layout.TrackFloating`
+
+    - Fixed a bug that prevented changing focus on inactive workspaces.
+
 ## 0.16
 
 ### Breaking Changes
diff --git a/XMonad/Layout/TrackFloating.hs b/XMonad/Layout/TrackFloating.hs
index d75f678f..8d682e0e 100644
--- a/XMonad/Layout/TrackFloating.hs
+++ b/XMonad/Layout/TrackFloating.hs
@@ -51,7 +51,7 @@ data TrackFloating a = TrackFloating (Maybe Window)
 instance LayoutModifier TrackFloating Window where
     modifyLayoutWithUpdate (TrackFloating mw) ws@(W.Workspace{ W.stack = ms }) r
       = do
-        xCur <- gets (W.peek . windowset)
+        xCur <- gets (W.peek . W.view (W.tag ws) . windowset)
         let isF = xCur /= (W.focus <$> ms)
             -- use the remembered focus point when true focus differs from
             -- what this (sub)layout is given, which happens e.g. when true
@@ -75,7 +75,7 @@ data UseTransientFor a = UseTransientFor deriving (Read,Show,Eq)
 
 instance LayoutModifier UseTransientFor Window where
     modifyLayout _ ws@(W.Workspace{ W.stack = ms }) r = do
-        m <- gets (W.peek . windowset)
+        m <- gets (W.peek . W.view (W.tag ws) . windowset)
         d <- asks display
         parent <- join <$> T.traverse (io . getTransientForHint d) m