dix: release all buttons and keys before reattaching a device (#34182)

Testcase:
  xinput float <keyboard name>

results in the keyboard's enter key being repeated as the device is detached
while the key is still physically down. To avoid this, release all keys and
buttons before reattaching the device.

X.Org Bug 34182 <http://bugs.freedesktop.org/show_bug.cgi?id=34182>

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Fernando Carrijo <fcarrijo@freedesktop.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/dix/devices.c b/dix/devices.c
index 6c0dc42a4..b73fb2948 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -2376,6 +2376,46 @@ RecalculateMasterButtons(DeviceIntPtr slave)
 }
 
 /**
+ * Generate release events for all keys/button currently down on this
+ * device.
+ */
+static void
+ReleaseButtonsAndKeys(DeviceIntPtr dev)
+{
+    EventListPtr        eventlist = InitEventList(GetMaximumEventsNum());
+    ButtonClassPtr      b = dev->button;
+    KeyClassPtr         k = dev->key;
+    int                 i, j, nevents;
+
+    if (!eventlist) /* no release events for you */
+        return;
+
+    /* Release all buttons */
+    for (i = 0; b && i < b->numButtons; i++)
+    {
+        if (BitIsOn(b->down, i))
+        {
+            nevents = GetPointerEvents(eventlist, dev, ButtonRelease, i, 0, NULL);
+            for (j = 0; j < nevents; j++)
+                mieqProcessDeviceEvent(dev, (InternalEvent*)(eventlist+j)->event, NULL);
+        }
+    }
+
+    /* Release all keys */
+    for (i = 0; k && i < MAP_LENGTH; i++)
+    {
+        if (BitIsOn(k->down, i))
+        {
+            nevents = GetKeyboardEvents(eventlist, dev, KeyRelease, i);
+            for (j = 0; j < nevents; j++)
+                mieqProcessDeviceEvent(dev, (InternalEvent*)(eventlist+j)->event, NULL);
+        }
+    }
+
+    FreeEventList(eventlist, GetMaximumEventsNum());
+}
+
+/**
  * Attach device 'dev' to device 'master'.
  * Client is set to the client that issued the request, or NULL if it comes
  * from some internal automatic pairing.
@@ -2408,6 +2448,8 @@ AttachDevice(ClientPtr client, DeviceIntPtr dev, DeviceIntPtr master)
         free(dev->spriteInfo->sprite);
     }
 
+    ReleaseButtonsAndKeys(dev);
+
     oldmaster = dev->u.master;
     dev->u.master = master;