rio: preserve window z-order on resize, fix race conditions

sort the window array by w->topped before reshaping all
windows. this preserves the window z-order.

remove implicit focus change on reshape/move. it called
wcurrent() in wtcl thread which might send a wctl message
to itself, bad... also we might not want to change focus
on reshape, like for the rio resize. so we set the input
window explicitely in all call sites.

window deletion was racy. wclosewin() destroys w->i, but
it is called outside the wctl thread so it might just
free the image under libframe doing some text selection.
this is fixed the following: add wclunk() function,
which basically just marks the window as deleted and
removes the reference from the window[] and hidden[]
arrays. (called on wclose() when refcount drops to
zero). wclosewin() now just frees the image and is only
called from the wctl thread on exit or when handing
the Deleted message.

get a reference to the window when doing sweeping or
moving as the filesystem might just clunk it under
us and we might end up sending wctl messages to
a Exited window.

wctl resize message has to fail if the window is not
current as it might be hidden... would also be annoying.

5 files changed, 218 insertions, 178 deletions

diff --git a/sys/src/cmd/rio/dat.h b/sys/src/cmd/rio/dat.h
index 17d0747ae..d74d6e425 100644
--- a/sys/src/cmd/rio/dat.h
+++ b/sys/src/cmd/rio/dat.h
@@ -67,6 +67,7 @@ enum	/* control messages */
 	Rawoff,
 	Holdon,
 	Holdoff,
+	Repaint,
 	Deleted,
 	Exited,
 };
@@ -194,6 +195,7 @@ uint		wbacknl(Window*, uint, uint);
 uint		winsert(Window*, Rune*, int, uint);
 void		waddraw(Window*, Rune*, int);
 void		wborder(Window*, int);
+void		wclunk(Window*);
 void		wclosewin(Window*);
 void		wcurrent(Window*);
 void		wcut(Window*);
diff --git a/sys/src/cmd/rio/fns.h b/sys/src/cmd/rio/fns.h
index d6e152e35..702eb101e 100644
--- a/sys/src/cmd/rio/fns.h
+++ b/sys/src/cmd/rio/fns.h
@@ -1,6 +1,6 @@
 void	keyboardsend(char*, int);
 int	whide(Window*);
-int	wunhide(int);
+int	wunhide(Window*);
 void	freescrtemps(void);
 int	parsewctl(char**, Rectangle, Rectangle*, int*, int*, int*, int*, char**, char*, char*);
 int	writewctl(Xfid*, char*);
diff --git a/sys/src/cmd/rio/rio.c b/sys/src/cmd/rio/rio.c
index 87137e483..98d3dd10b 100644
--- a/sys/src/cmd/rio/rio.c
+++ b/sys/src/cmd/rio/rio.c
@@ -347,7 +347,7 @@ keyboardthread(void*)
 	while(s = recvp(kbdchan)){
 		if(*s == 'k' || *s == 'K')
 			shiftdown = utfrune(s+1, Kshift) != nil;
-		if(input == nil || sendp(input->ck, s) <= 0)
+		if(input == nil || input->deleted || sendp(input->ck, s) <= 0)
 			free(s);
 	}
 }
@@ -470,7 +470,7 @@ void
 mousethread(void*)
 {
 	int sending, inside, scrolling, moving, band;
-	Window *oin, *w, *winput;
+	Window *w, *winput;
 	Image *i;
 	Rectangle r;
 	Point xy;
@@ -513,7 +513,7 @@ mousethread(void*)
 				wtopme(wkeyboard);
 				winput = wkeyboard;
 			}
-			if(winput!=nil && winput->i!=nil){
+			if(winput!=nil && !winput->deleted && winput->i!=nil){
 				/* convert to logical coordinates */
 				xy.x = mouse->xy.x + (winput->i->r.min.x-winput->screenr.min.x);
 				xy.y = mouse->xy.y + (winput->i->r.min.y-winput->screenr.min.y);
@@ -555,7 +555,7 @@ mousethread(void*)
 			else
 				riosetcursor(nil, 0);
 			if(moving && (mouse->buttons&7)){
-				oin = winput;
+				incref(winput);
 				band = mouse->buttons & 3;
 				sweeping = 1;
 				if(band)
@@ -564,18 +564,19 @@ mousethread(void*)
 					i = drag(winput, &r);
 				sweeping = 0;
 				if(i != nil){
-					if(winput == oin){
-						if(band)
-							wsendctlmesg(winput, Reshaped, i->r, i);
-						else
-							wsendctlmesg(winput, Moved, r, i);
-						cornercursor(winput, mouse->xy, 1);
-					}else
-						freeimage(i);
+					if(band)
+						wsendctlmesg(winput, Reshaped, i->r, i);
+					else
+						wsendctlmesg(winput, Moved, r, i);
+					cornercursor(winput, mouse->xy, 1);
+				}
+				if(wclose(winput) == 0)
+					w = winput;
+				else {
+					riosetcursor(nil, 0);
+					w = nil;
 				}
 			}
-			if(w != nil)
-				cornercursor(w, mouse->xy, 0);
 			/* we're not sending the event, but if button is down maybe we should */
 			if(mouse->buttons){
 				/* w->topped will be zero or less if window has been bottomed */
@@ -583,8 +584,11 @@ mousethread(void*)
 					if(mouse->buttons & 1){
 						;
 					}else if(mouse->buttons & 2){
-						if(winput && !winput->mouseopen)
+						if(winput && !winput->deleted && !winput->mouseopen){
+							incref(winput);
 							button2menu(winput);
+							wclose(winput);
+						}
 					}else if(mouse->buttons & 4)
 						button3menu();
 				}else{
@@ -607,11 +611,17 @@ mousethread(void*)
 		}
 }
 
+int
+wtopcmp(void *a, void *b)
+{
+	return (*(Window**)a)->topped - (*(Window**)b)->topped;
+}
+
 void
 resized(void)
 {
 	Image *im;
-	int i, j, ishidden;
+	int i, j;
 	Rectangle r;
 	Point o, n;
 	Window *w;
@@ -627,10 +637,9 @@ resized(void)
 	draw(view, view->r, background, nil, ZP);
 	o = subpt(viewr.max, viewr.min);
 	n = subpt(view->clipr.max, view->clipr.min);
+	qsort(window, nwindow, sizeof(window[0]), wtopcmp);
 	for(i=0; i<nwindow; i++){
 		w = window[i];
-		if(w->deleted)
-			continue;
 		r = rectsubpt(w->i->r, viewr.min);
 		r.min.x = (r.min.x*n.x)/o.x;
 		r.min.y = (r.min.y*n.y)/o.y;
@@ -639,26 +648,25 @@ resized(void)
 		if(!goodrect(r))
 			r = rectsubpt(w->i->r, viewr.min);
 		r = rectaddpt(r, screen->clipr.min);
-		ishidden = 0;
 		for(j=0; j<nhidden; j++)
-			if(w == hidden[j]){
-				ishidden = 1;
+			if(w == hidden[j])
 				break;
-			}
-		if(ishidden){
+		incref(w);
+		if(j < nhidden){
 			im = allocimage(display, r, screen->chan, 0, DWhite);
 			r = ZR;
-		}else
+		} else
 			im = allocwindow(wscreen, r, Refbackup, DWhite);
 		if(im)
 			wsendctlmesg(w, Reshaped, r, im);
+		wclose(w);
 	}
 	viewr = screen->r;
 	flushimage(display, 1);
 }
 
-static int
-wcovered(Window *w, Rectangle r, int i)
+int
+obscured(Window *w, Rectangle r, int i)
 {
 	Window *t;
 
@@ -668,21 +676,21 @@ wcovered(Window *w, Rectangle r, int i)
 		return 1;
 	for(; i<nwindow; i++){
 		t = window[i];
-		if(t == w || t->topped <= w->topped || t->deleted)
+		if(t == w || t->topped <= w->topped)
 			continue;
 		if(Dx(t->screenr) == 0 || Dy(t->screenr) == 0 || rectXrect(r, t->screenr) == 0)
 			continue;
 		if(r.min.y < t->screenr.min.y)
-			if(!wcovered(w, Rect(r.min.x, r.min.y, r.max.x, t->screenr.min.y), i))
+			if(!obscured(w, Rect(r.min.x, r.min.y, r.max.x, t->screenr.min.y), i))
 				return 0;
 		if(r.min.x < t->screenr.min.x)
-			if(!wcovered(w, Rect(r.min.x, r.min.y, t->screenr.min.x, r.max.y), i))
+			if(!obscured(w, Rect(r.min.x, r.min.y, t->screenr.min.x, r.max.y), i))
 				return 0;
 		if(r.max.y > t->screenr.max.y)
-			if(!wcovered(w, Rect(r.min.x, t->screenr.max.y, r.max.x, r.max.y), i))
+			if(!obscured(w, Rect(r.min.x, t->screenr.max.y, r.max.x, r.max.y), i))
 				return 0;
 		if(r.max.x > t->screenr.max.x)
-			if(!wcovered(w, Rect(t->screenr.max.x, r.min.y, r.max.x, r.max.y), i))
+			if(!obscured(w, Rect(t->screenr.max.x, r.min.y, r.max.x, r.max.y), i))
 				return 0;
 		return 1;
 	}
@@ -699,13 +707,12 @@ button3menu(void)
 		for(j=0; j<n; j++)
 			if(window[i] == hidden[j])
 				break;
-		if(j < n || window[i]->deleted)
-			continue;
-		if(wcovered(window[i], window[i]->screenr, 0)){
-			hidden[n++] = window[i];
-			if(n >= nelem(hidden))
-				break;
-		}
+		if(j == n)
+			if(obscured(window[i], window[i]->screenr, 0)){
+				hidden[n++] = window[i];
+				if(n >= nelem(hidden))
+					break;
+			}
 	}
 	if(n >= nelem(menu3str)-Hidden)
 		n = nelem(menu3str)-Hidden-1;
@@ -752,9 +759,6 @@ button3menu(void)
 void
 button2menu(Window *w)
 {
-	if(w->deleted)
-		return;
-	incref(w);
 	if(w->scrolling)
 		menu2str[Scroll] = "noscroll";
 	else
@@ -803,7 +807,6 @@ button2menu(Window *w)
 			wshow(w, w->nr);
 		break;
 	}
-	wclose(w);
 	wsendctlmesg(w, Wakeup, ZR, nil);
 	flushimage(display, 1);
 }
@@ -1113,9 +1116,13 @@ resize(void)
 	w = pointto(TRUE);
 	if(w == nil)
 		return;
+	incref(w);
 	i = sweep();
-	if(i)
+	if(i){
 		wsendctlmesg(w, Reshaped, i->r, i);
+		wcurrent(w);
+	}
+	wclose(w);
 }
 
 void
@@ -1128,10 +1135,14 @@ move(void)
 	w = pointto(FALSE);
 	if(w == nil)
 		return;
+	incref(w);
 	i = drag(w, &r);
-	if(i)
+	if(i){
 		wsendctlmesg(w, Moved, r, i);
-	cornercursor(input, mouse->xy, 1);
+		wcurrent(w);
+	}
+	cornercursor(w, mouse->xy, 1);
+	wclose(w);
 }
 
 int
@@ -1145,38 +1156,39 @@ whide(Window *w)
 			return -1;
 	if(nhidden >= nelem(hidden))
 		return 0;
+	incref(w);
 	i = allocimage(display, w->screenr, w->i->chan, 0, DWhite);
 	if(i){
+		if(w == input)
+			input = nil;
 		hidden[nhidden++] = w;
 		wsendctlmesg(w, Reshaped, ZR, i);
-		return 1;
 	}
-	return 0;
+	wclose(w);
+	return i!=0;
 }
 
 int
-wunhide(int h)
+wunhide(Window *w)
 {
+	int j;
 	Image *i;
-	Window *w;
 
-	w = hidden[h];
-	if(w == nil)
-		return 0;
-	if(h >= nhidden){
-		wtopme(w);
-		wcurrent(w);
-		flushimage(display, 1);
-		return 1;
-	}
+	for(j=0; j<nhidden; j++)
+		if(hidden[j] == w)
+			break;
+	if(j == nhidden)
+		return -1;	/* not hidden */
+	incref(w);
 	i = allocwindow(wscreen, w->i->r, Refbackup, DWhite);
 	if(i){
 		--nhidden;
-		memmove(hidden+h, hidden+h+1, (nhidden-h)*sizeof(Window*));
+		memmove(hidden+j, hidden+j+1, (nhidden-j)*sizeof(Window*));
 		wsendctlmesg(w, Reshaped, w->i->r, i);
-		return 1;
+		wcurrent(w);
 	}
-	return 0;
+	wclose(w);
+	return i!=0;
 }
 
 void
@@ -1185,16 +1197,34 @@ hide(void)
 	Window *w;
 
 	w = pointto(TRUE);
-	if(w == nil)
-		return;
-	whide(w);
+	if(w)
+		whide(w);
 }
 
 void
-unhide(int h)
+unhide(int j)
 {
-	if(h >= Hidden)
-		wunhide(h - Hidden);
+	Window *w;
+
+	if(j < Hidden)
+		return;
+	j -= Hidden;
+	w = hidden[j];
+	if(w == nil)
+		return;
+	if(j < nhidden){
+		wunhide(w);
+		return;
+	}
+	/* uncover obscured window */
+	for(j=0; j<nwindow; j++)
+		if(window[j] == w){
+			incref(w);
+			wcurrent(w);
+			wtopme(w);
+			wclose(w);
+			return;
+		}
 }
 
 Window*
@@ -1207,6 +1237,10 @@ new(Image *i, int hideit, int scrollit, int pid, char *dir, char *cmd, char **ar
 
 	if(i == nil)
 		return nil;
+	if(hideit && nhidden >= nelem(hidden)){
+		freeimage(i);
+		return nil;
+	}
 	cm = chancreate(sizeof(Mouse), 0);
 	ck = chancreate(sizeof(char*), 0);
 	cctl = chancreate(sizeof(Wctlmesg), 4);
@@ -1221,8 +1255,6 @@ new(Image *i, int hideit, int scrollit, int pid, char *dir, char *cmd, char **ar
 	free(mc);	/* wmk copies *mc */
 	window = erealloc(window, ++nwindow*sizeof(Window*));
 	window[nwindow-1] = w;
-	if(nhidden >= nelem(hidden))
-		hideit = 0;
 	if(hideit){
 		hidden[nhidden++] = w;
 		w->screenr = ZR;
diff --git a/sys/src/cmd/rio/wctl.c b/sys/src/cmd/rio/wctl.c
index 2e91b0e7c..557e9e84d 100644
--- a/sys/src/cmd/rio/wctl.c
+++ b/sys/src/cmd/rio/wctl.c
@@ -346,68 +346,32 @@ wctlnew(Rectangle rect, char *arg, int pid, int hideit, int scrollit, char *dir,
 }
 
 int
-writewctl(Xfid *x, char *err)
+wctlcmd(Window *w, Rectangle r, int cmd, char *err)
 {
-	int cnt, cmd, j, id, hideit, scrollit, pid;
 	Image *i;
-	char *arg, *dir;
-	Rectangle rect;
-	Window *w;
-
-	w = x->f->w;
-	cnt = x->count;
-	x->data[cnt] = '\0';
-	id = 0;
-
-	rect = rectsubpt(w->screenr, screen->r.min);
-	cmd = parsewctl(&arg, rect, &rect, &pid, &id, &hideit, &scrollit, &dir, x->data, err);
-	if(cmd < 0)
-		return -1;
-
-	if(mouse->buttons!=0 && cmd>=Top){
-		strcpy(err, "action disallowed when mouse active");
-		return -1;
-	}
-
-	if(id != 0){
-		for(j=0; j<nwindow; j++)
-			if(window[j]->id == id)
-				break;
-		if(j == nwindow){
-			strcpy(err, "no such window id");
-			return -1;
-		}
-		w = window[j];
-		if(w->deleted || w->i==nil){
-			strcpy(err, "window deleted");
-			return -1;
-		}
-	}
 
 	switch(cmd){
-	case New:
-		return wctlnew(rect, arg, pid, hideit, scrollit, dir, err);
-	case Set:
-		if(pid > 0)
-			wsetpid(w, pid, 0);
-		return 1;
 	case Move:
-		rect = Rect(rect.min.x, rect.min.y, rect.min.x+Dx(w->screenr), rect.min.y+Dy(w->screenr));
-		rect = rectonscreen(rect);
+		r = Rect(r.min.x, r.min.y, r.min.x+Dx(w->screenr), r.min.y+Dy(w->screenr));
+		r = rectonscreen(r);
 		/* fall through */
 	case Resize:
-		if(!goodrect(rect)){
+		if(!goodrect(r)){
 			strcpy(err, Ebadwr);
 			return -1;
 		}
-		if(eqrect(rect, w->screenr))
+		if(w != input){
+			strcpy(err, "window not current");
+			return -1;
+		}
+		if(eqrect(r, w->screenr))
 			return 1;
-		i = allocwindow(wscreen, rect, Refbackup, DWhite);
+		i = allocwindow(wscreen, r, Refbackup, DWhite);
 		if(i == nil){
 			strcpy(err, Ewalloc);
 			return -1;
 		}
-		border(i, rect, Selborder, red, ZP);
+		border(i, r, Selborder, red, ZP);
 		wsendctlmesg(w, Reshaped, i->r, i);
 		return 1;
 	case Scroll:
@@ -441,26 +405,68 @@ writewctl(Xfid *x, char *err)
 		}
 		return 1;
 	case Unhide:
-		for(j=0; j<nhidden; j++)
-			if(hidden[j] == w)
-				break;
-		if(j == nhidden){
+		switch(wunhide(w)){
+		case -1:
 			strcpy(err, "window not hidden");
 			return -1;
-		}
-		if(wunhide(j) == 0){
+		case 0:
 			strcpy(err, "hide failed");
 			return -1;
+		default:
+			break;
 		}
 		return 1;
 	case Delete:
 		wsendctlmesg(w, Deleted, ZR, nil);
 		return 1;
 	}
+
 	strcpy(err, "invalid wctl message");
 	return -1;
 }
 
+int
+writewctl(Xfid *x, char *err)
+{
+	int cnt, cmd, id, hideit, scrollit, pid;
+	char *arg, *dir;
+	Rectangle r;
+	Window *w;
+
+	w = x->f->w;
+	cnt = x->count;
+	x->data[cnt] = '\0';
+	id = 0;
+
+	r = rectsubpt(w->screenr, screen->r.min);
+	cmd = parsewctl(&arg, r, &r, &pid, &id, &hideit, &scrollit, &dir, x->data, err);
+	if(cmd < 0)
+		return -1;
+
+	if(id != 0){
+		w = wlookid(id);
+		if(w == 0){
+			strcpy(err, "no such window id");
+			return -1;
+		}
+	}
+
+	switch(cmd){
+	case New:
+		return wctlnew(r, arg, pid, hideit, scrollit, dir, err);
+	case Set:
+		if(pid > 0)
+			wsetpid(w, pid, 0);
+		return 1;
+	}
+
+	incref(w);
+	id = wctlcmd(w, r, cmd, err);
+	wclose(w);
+
+	return id;
+}
+
 void
 wctlthread(void *v)
 {
diff --git a/sys/src/cmd/rio/wind.c b/sys/src/cmd/rio/wind.c
index b9c56ab6e..dc7d4a88a 100644
--- a/sys/src/cmd/rio/wind.c
+++ b/sys/src/cmd/rio/wind.c
@@ -131,7 +131,6 @@ wresize(Window *w, Image *i, int move)
 		draw(i, i->r, w->i, nil, w->i->r.min);
 	freeimage(w->i);
 	w->i = i;
-	wsetname(w);
 	w->mc.image = i;
 	r = insetrect(i->r, Selborder+1);
 	w->scrollr = r;
@@ -151,10 +150,15 @@ wresize(Window *w, Image *i, int move)
 		wsetselect(w, w->q0, w->q1);
 		wscrdraw(w);
 	}
-	wborder(w, Selborder);
+	if(w == input)
+		wborder(w, Selborder);
+	else
+		wborder(w, Unselborder);
+	wsetname(w);
 	w->topped = ++topped;
 	w->resized = TRUE;
 	w->mouse.counter++;
+	w->wctlready = 1;
 }
 
 void
@@ -189,7 +193,7 @@ wclose(Window *w)
 	if(i < 0)
 		error("negative ref count");
 	if(!w->deleted)
-		wclosewin(w);
+		wclunk(w);
 	wsendctlmesg(w, Exited, ZR, nil);
 	return 1;
 }
@@ -1121,24 +1125,16 @@ wctlmesg(Window *w, int m, Rectangle r, Image *i)
 		w->screenr = r;
 		strcpy(buf, w->name);
 		wresize(w, i, m==Moved);
-		w->wctlready = 1;
 		proccreate(deletetimeoutproc, estrdup(buf), 4096);
-		if(Dx(r) > 0){
-			if(w != input)
-				wcurrent(w);
-		}else if(w == input)
-			wcurrent(nil);
-		flushimage(display, 1);
 		break;
 	case Refresh:
-		if(w->deleted || Dx(w->screenr)<=0 || !rectclip(&r, w->i->r))
+		if(w->deleted || Dx(w->screenr)<=0 || !rectclip(&r, w->i->r) || w->mouseopen)
 			break;
-		if(!w->mouseopen)
-			wrefresh(w, r);
+		wrefresh(w, r);
 		flushimage(display, 1);
 		break;
 	case Movemouse:
-		if(sweeping || !ptinrect(r.min, w->i->r))
+		if(w->deleted || Dx(w->screenr)<=0 || !ptinrect(r.min, w->i->r))
 			break;
 		wmovemouse(w, r.min);
 	case Rawon:
@@ -1154,6 +1150,7 @@ wctlmesg(Window *w, int m, Rectangle r, Image *i)
 		break;
 	case Holdon:
 	case Holdoff:
+	case Repaint:
 		if(w->deleted)
 			break;
 		wrepaint(w);
@@ -1162,11 +1159,13 @@ wctlmesg(Window *w, int m, Rectangle r, Image *i)
 	case Deleted:
 		if(w->deleted)
 			break;
+		wclunk(w);
 		write(w->notefd, "hangup", 6);
 		proccreate(deletetimeoutproc, estrdup(w->name), 4096);
 		wclosewin(w);
 		break;
 	case Exited:
+		wclosewin(w);
 		frclear(w, TRUE);
 		close(w->notefd);
 		chanfree(w->mc.c);
@@ -1193,6 +1192,8 @@ wctlmesg(Window *w, int m, Rectangle r, Image *i)
 void
 wmovemouse(Window *w, Point p)
 {
+	if(w != input || menuing || sweeping)
+		return;
 	p.x += w->screenr.min.x-w->i->r.min.x;
 	p.y += w->screenr.min.y-w->i->r.min.y;
 	moveto(mousectl, p);
@@ -1216,7 +1217,6 @@ wborder(Window *w, int type)
 		else
 			col = lighttitlecol;
 	}
-
 	border(w->i, w->i->r, Selborder, col, ZP);
 }
 
@@ -1230,7 +1230,6 @@ wpointto(Point pt)
 	for(i=0; i<nwindow; i++){
 		v = window[i];
 		if(ptinrect(pt, v->screenr))
-		if(!v->deleted)
 		if(w==nil || v->topped>w->topped)
 			w = v;
 	}
@@ -1246,20 +1245,14 @@ wcurrent(Window *w)
 		return;
 	oi = input;
 	input = w;
-	if(oi!=w && oi!=nil)
-		wrepaint(oi);
-	if(w !=nil){
-		wrepaint(w);
-		wsetcursor(w, 0);
-	}
 	if(w != oi){
 		if(oi){
 			oi->wctlready = 1;
-			wsendctlmesg(oi, Wakeup, ZR, nil);
+			wsendctlmesg(oi, Repaint, ZR, nil);
 		}
 		if(w){
 			w->wctlready = 1;
-			wsendctlmesg(w, Wakeup, ZR, nil);
+			wsendctlmesg(w, Repaint, ZR, nil);
 		}
 	}
 }
@@ -1269,7 +1262,7 @@ wsetcursor(Window *w, int force)
 {
 	Cursor *p;
 
-	if(w==nil || /*w!=input || */ w->i==nil || Dx(w->screenr)<=0)
+	if(w==nil || w->deleted || w->i==nil || Dx(w->screenr)<=0)
 		p = nil;
 	else if(wpointto(mouse->xy) == w){
 		p = w->cursorp;
@@ -1290,30 +1283,14 @@ riosetcursor(Cursor *p, int force)
 	lastcursor = p;
 }
 
-Window*
-wtop(Point pt)
-{
-	Window *w;
-
-	w = wpointto(pt);
-	if(w){
-		if(w->topped == topped)
-			return nil;
-		topwindow(w->i);
-		wcurrent(w);
-		flushimage(display, 1);
-		w->topped = ++topped;
-	}
-	return w;
-}
 
 void
 wtopme(Window *w)
 {
 	if(w!=nil && w->i!=nil && !w->deleted && w->topped!=topped){
+		w->topped = ++topped;
 		topwindow(w->i);
 		flushimage(display, 1);
-		w->topped = ++topped;
 	}
 }
 
@@ -1321,13 +1298,30 @@ void
 wbottomme(Window *w)
 {
 	if(w!=nil && w->i!=nil && !w->deleted){
+		w->topped = - ++topped;
 		bottomwindow(w->i);
 		flushimage(display, 1);
-		w->topped = - ++topped;
 	}
 }
 
 Window*
+wtop(Point pt)
+{
+	Window *w;
+
+	w = wpointto(pt);
+	if(w){
+		if(w->topped == topped)
+			return nil;
+		incref(w);
+		wcurrent(w);
+		wtopme(w);
+		wclose(w);
+	}
+	return w;
+}
+
+Window*
 wlookid(int id)
 {
 	int i;
@@ -1339,12 +1333,10 @@ wlookid(int id)
 }
 
 void
-wclosewin(Window *w)
+wclunk(Window *w)
 {
-	Rectangle r;
 	int i;
 
-	w->deleted = TRUE;
 	if(w == input){
 		input = nil;
 		wsetcursor(w, 0);
@@ -1360,16 +1352,24 @@ wclosewin(Window *w)
 	for(i=0; i<nwindow; i++)
 		if(window[i] == w){
 			--nwindow;
-			memmove(window+i, window+i+1, (nwindow-i)*sizeof(Window*));
-			w->deleted = TRUE;
-			r = w->i->r;
-			/* move it off-screen to hide it, in case client is slow in letting it go */
-			MOVEIT originwindow(w->i, r.min, view->r.max);
-			freeimage(w->i);
-			w->i = nil;
-			return;
+			memmove(window+i, window+i+1, (nwindow-i)*sizeof(window[0]));
+			break;
 		}
-	error("unknown window in closewin");
+	w->deleted = TRUE;
+}
+
+void
+wclosewin(Window *w)
+{
+	Image *i;
+
+	i = w->i;
+	if(i){
+		w->i = nil;
+		/* move it off-screen to hide it, in case client is slow in letting it go */
+		MOVEIT originwindow(i, i->r.min, view->r.max);
+		freeimage(i);
+	}
 }
 
 void