[PATCH xserver] os/inputthread: Ensure pollfd refreshing

[Mihail Konev]

When putting a device node into a poll-request list, do not overwrite a
"please-remove" element with the same fd, so that a closed device file
is ospoll_remove'd prior to being ospoll_add'ed.

Before, the opposite order was possible, resulting in ospoll_add
considering the newly opened file being already polled, should it have a
fd for which the "please-remove" has not been procesed yet. In this
case, no further events would be seen from the device.

Signed-off-by: Mihail Konev <k.mvc at ya.ru>
Regressed-in: 52d6a1e832a5e62289dd4f32824ae16a78dfd7e8
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97880
Patchwork: https://patchwork.freedesktop.org/patch/113763/
Hit-and-Reduced-by: Hans de Goede <hdegoede at redhat.com>
Reviewed-and-Reduced-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 os/inputthread.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/os/inputthread.c b/os/inputthread.c
index 6aa0a9ce6fb5..ddafa7fe8343 100644
--- a/os/inputthread.c
+++ b/os/inputthread.c
@@ -197,7 +197,7 @@ InputThreadRegisterDev(int fd,
 
     dev = NULL;
     xorg_list_for_each_entry(old, &inputThreadInfo->devs, node) {
-        if (old->fd == fd) {
+        if (old->fd == fd && old->state != device_state_removed) {
             dev = old;
             break;
         }
@@ -218,6 +218,9 @@ InputThreadRegisterDev(int fd,
         dev->readInputProc = readInputProc;
         dev->readInputArgs = readInputArgs;
         dev->state = device_state_added;
+
+        /* Do not prepend, so that any dev->state == device_state_removed
+         * with the same dev->fd get processed first. */
         xorg_list_append(&dev->node, &inputThreadInfo->devs);
     }
 
-- 
2.9.2