fix unintended window hiding

the refactoring that introduced `nsHideOnCondition` caused a
misbehaviour in `nsSingleScratchpadPerWorkspace`, leading to unintended
window hiding. Now, when opening a new scratchpad, only the previous
active scratchpad is hidden.

Author: philib

CHANGES.md

@@ -50,6 +50,11 @@
     - Added `focusWorkspace` for focusing workspaces on the screen that they
       belong to.
 
+  * `XMonad.Util.NamedScratchPad`
+
+    - Fix unintended window hiding in `nsSingleScratchpadPerWorkspace`.
+      Only hide the previously active scratchpad.
+
 ## 0.18.1 (August 20, 2024)
 
 ### Breaking Changes

XMonad/Util/NamedScratchpad.hs

@@ -309,7 +309,7 @@ nsSingleScratchpadPerWorkspace :: NamedScratchpads -> X ()
 nsSingleScratchpadPerWorkspace scratches =
     nsHideOnCondition $ \ _lastFocus curFocus winSet hideScratch -> do
         allScratchesButCurrent <-
-            filterM (liftA2 (<||>) (pure . (/= curFocus)) (`isNSP` scratches))
+            filterM (liftA2 (<&&>) (pure . (/= curFocus)) (`isNSP` scratches))
                     (W.index winSet)
         whenX (isNSP curFocus scratches) $
             for_ allScratchesButCurrent hideScratch