From 606a8dc73d91a198d72d249934dc027a23f4c338 Mon Sep 17 00:00:00 2001
From: Ben Byer <bbyer@bbyer.local>
Date: Wed, 31 Oct 2007 03:39:47 -0700
Subject: [PATCH] Darwin: Trap Deactivate messages and release modifiers to
 avoid "stuck shift lock" (etc) bugs (cherry picked from commit
 2b189a99330eb465fa0d17020fb1db1e38829151)

---
 hw/darwin/darwinEvents.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/hw/darwin/darwinEvents.c b/hw/darwin/darwinEvents.c
index bc3a041a5..06c4cc7dd 100644
--- a/hw/darwin/darwinEvents.c
+++ b/hw/darwin/darwinEvents.c
@@ -147,6 +147,16 @@ static void DarwinUpdateModifiers(
     }
 }
 
+/*
+ * DarwinReleaseModifiers
+ * This hacky function releases all modifier keys.  It should be called when X11.app
+ * is deactivated (kXDarwinDeactivate) to prevent modifiers from getting stuck if they
+ * are held down during a "context" switch -- otherwise, we would miss the KeyUp.
+ */
+static void DarwinReleaseModifiers(void) {
+	xEvent e;
+	DarwinUpdateModifiers(&e, KeyRelease, COMMAND_MASK(-1) | CONTROL_MASK(-1) | ALTERNATE_MASK(-1) | SHIFT_MASK(-1));
+}
 
 /*
  * DarwinSimulateMouseClick
@@ -347,6 +357,9 @@ void ProcessInputEvents(void) {
 	      ErrorF("Unexpected XDarwinScrollWheel event in DarwinProcessInputEvents\n");
 	      break;
 
+			case kXDarwinDeactivate:
+				DarwinReleaseModifiers();
+				// fall through
             default:
                 // Check for mode specific event
                 DarwinModeProcessEvent(&xe);