[PATCH weston] xwm: Don't clear the selection if it has no text type available

Derek Foreman derekf at osg.samsung.com
Mon Feb 1 20:36:57 UTC 2016

weston maintains a copy of the most recently selected "thing" - it picks
the first available type when it copies, and saves that one only.

When an application quits weston will make the saved selection active.

When xwm sees the selection set it will check if any of the offered types
are text.  If no text type is offered it will clear the selection.

weston then interprets this in the same way as an application exiting and
causing the selection to be unset, and we get caught in a live lock with
both weston and xwayland consuming as much cpu as they can.

The simple fix is to just remove the test for text presence.

Signed-off-by: Derek Foreman <derekf at osg.samsung.com>

This is kind of an alternate solution to the problem fixed in

I don't understand why offers with no text type are cleared here,
and couldn't find why with git blame either.  Anyone know why
we've been doing this?

With this patch we can get somewhat odd behaviour - if terminology
exits with a selection it can only be pasted into another terminology
not a weston-terminal, because text wasn't the first offer and weston
only saves the first offer.

That seems better than a livelock though.  Maybe we can grab all available
offers when cloning the selection instead of just the first (but that should
be done in addition to this patch, I think, because we could have an app that
doesn't offer text at all exit with a selection set and cause the same lock)

 xwayland/selection.c | 28 ++++------------------------
 1 file changed, 4 insertions(+), 24 deletions(-)

diff --git a/xwayland/selection.c b/xwayland/selection.c
index 25ec848..24aa324 100644
--- a/xwayland/selection.c
+++ b/xwayland/selection.c
@@ -655,8 +655,6 @@ weston_wm_set_selection(struct wl_listener *listener, void *data)
 	struct weston_wm *wm =
 		container_of(listener, struct weston_wm, selection_listener);
 	struct weston_data_source *source = seat->selection_data_source;
-	const char **p, **end;
-	int has_text_plain = 0;
 	if (source == NULL) {
 		if (wm->selection_owner == wm->selection_window)
@@ -670,28 +668,10 @@ weston_wm_set_selection(struct wl_listener *listener, void *data)
 	if (source->send == data_source_send)
-	p = source->mime_types.data;
-	end = (const char **)
-		((char *) source->mime_types.data + source->mime_types.size);
-	while (p < end) {
-		weston_log("  %s\n", *p);
-		if (strcmp(*p, "text/plain") == 0 ||
-		    strcmp(*p, "text/plain;charset=utf-8") == 0)
-			has_text_plain = 1;
-		p++;
-	}
-	if (has_text_plain) {
-		xcb_set_selection_owner(wm->conn,
-					wm->selection_window,
-					wm->atom.clipboard,
-	} else {
-		xcb_set_selection_owner(wm->conn,
-					wm->atom.clipboard,
-	}
+	xcb_set_selection_owner(wm->conn,
+				wm->selection_window,
+				wm->atom.clipboard,

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