devdraw, acme, snarfer: remove 64KB snarf buffer limit

The snarf code silently dropped text larger than SnarfSize (64KB),
causing paste to produce nothing. Replace the static clip buffer
with a dynamically allocated one, remove all the size checks, and
read the actual X11 property size instead of capping at SnarfSize.

include/draw.h

@@ -547,10 +547,6 @@ extern	void		drawsetdebug(int);
 /*
  * Snarf buffer
  */
-enum
-{
-	SnarfSize = 64*1024
-};
 char *getsnarf(void);
 void putsnarf(char*);
 

src/cmd/acme/acme.c

@@ -1090,11 +1090,6 @@ iconinit(void)
  * fd here rather than use snarffd
  */
 
-/* rio truncates larges snarf buffers, so this avoids using the
- * service if the string is huge */
-
-#define MAXSNARF 100*1024
-
 void
 acmeputsnarf(void)
 {
@@ -1104,8 +1099,6 @@ acmeputsnarf(void)
 
 	if(snarfbuf.nc==0)
 		return;
-	if(snarfbuf.nc > MAXSNARF)
-		return;
 
 	fmtstrinit(&f);
 	for(i=0; i<snarfbuf.nc; i+=n){

src/cmd/devdraw/mac-screen.m

@@ -1109,7 +1109,7 @@ rpc_getsnarf(void)
 void
 rpc_putsnarf(char *s)
 {
-	if(s == nil || strlen(s) >= SnarfSize)
+	if(s == nil)
 		return;
 
 	dispatch_sync(dispatch_get_main_queue(), ^(void) {

src/cmd/devdraw/x11-screen.c

@@ -1454,9 +1454,8 @@ rpc_setcursor(Client *client, Cursor *c, Cursor2 *c2)
 
 struct {
 	QLock lk;
-	char buf[SnarfSize];
+	char *buf;
 #ifdef APPLESNARF
-	Rune rbuf[SnarfSize];
 	PasteboardRef apple;
 #endif
 } clip;
@@ -1498,7 +1497,7 @@ _xgetsnarffrom(Xwin *w, XWindow xw, Atom clipboard, Atom target, int timeout0, i
 
 	/* get the property */
 	xdata = nil;
-	XGetWindowProperty(_x.display, w->drawable, prop, 0, SnarfSize/sizeof(ulong), 0,
+	XGetWindowProperty(_x.display, w->drawable, prop, 0, (len+3)/4, 0,
 		AnyPropertyType, &type, &fmt, &len, &dummy, &xdata);
 	if((type != target && type != XA_STRING && type != _x.utf8string) || len == 0){
 		if(xdata)
@@ -1538,7 +1537,9 @@ rpc_getsnarf(void)
 	// TODO check more
 	if(xw == w->drawable){
 	mine:
-		data = (uchar*)strdup(clip.buf);
+		data = nil;
+		if(clip.buf != nil)
+			data = (uchar*)strdup(clip.buf);
 		goto out;
 	}
 
@@ -1577,12 +1578,11 @@ __xputsnarf(char *data)
 	XButtonEvent e;
 	Xwin *w;
 
-	if(strlen(data) >= SnarfSize)
-		return;
 	qlock(&clip.lk);
 	xlock();
 	w = _x.windows;
-	strcpy(clip.buf, data);
+	free(clip.buf);
+	clip.buf = strdup(data);
 	/* leave note for mouse proc to assert selection ownership */
 	_x.putsnarf++;
 
@@ -1627,8 +1627,12 @@ if(0) fprint(2, "xselect target=%d requestor=%d property=%d selection=%d (sizeof
 		/* text/plain;charset=utf-8 is used by xfce4-terminal 1.0.4 */
 		/* if the target is STRING we're supposed to reply with Latin1 XXX */
 		qlock(&clip.lk);
-		XChangeProperty(_x.display, xe->requestor, xe->property, xe->target,
-			8, PropModeReplace, (uchar*)clip.buf, strlen(clip.buf));
+		if(clip.buf)
+			XChangeProperty(_x.display, xe->requestor, xe->property, xe->target,
+				8, PropModeReplace, (uchar*)clip.buf, strlen(clip.buf));
+		else
+			XChangeProperty(_x.display, xe->requestor, xe->property, xe->target,
+				8, PropModeReplace, (uchar*)"", 0);
 		qunlock(&clip.lk);
 	}else{
 		if(strcmp(name, "TIMESTAMP") != 0)
@@ -1674,7 +1678,9 @@ _applegetsnarf(void)
 	}
 	flags = PasteboardSynchronize(clip.apple);
 	if(flags&kPasteboardClientIsOwner){
-		s = strdup(clip.buf);
+		s = nil;
+		if(clip.buf != nil)
+			s = strdup(clip.buf);
 		qunlock(&clip.lk);
 		return s;
 	}
@@ -1716,14 +1722,21 @@ _appleputsnarf(char *s)
 {
 	CFDataRef cfdata;
 	PasteboardSyncFlags flags;
+	Rune *r;
+	int n;
 
 /*	fprint(2, "appleputsnarf\n"); */
 
-	if(strlen(s) >= SnarfSize)
-		return;
 	qlock(&clip.lk);
-	strcpy(clip.buf, s);
-	runesnprint(clip.rbuf, nelem(clip.rbuf), "%s", s);
+	free(clip.buf);
+	clip.buf = strdup(s);
+	n = utflen(s) + 1;
+	r = malloc(n * sizeof(Rune));
+	if(r == nil){
+		qunlock(&clip.lk);
+		return;
+	}
+	runesnprint(r, n, "%s", s);
 	if(clip.apple == nil){
 		if(PasteboardCreate(kPasteboardClipboard, &clip.apple) != noErr){
 			fprint(2, "apple pasteboard create failed\n");
@@ -1733,17 +1746,20 @@ _appleputsnarf(char *s)
 	}
 	if(PasteboardClear(clip.apple) != noErr){
 		fprint(2, "apple pasteboard clear failed\n");
+		free(r);
 		qunlock(&clip.lk);
 		return;
 	}
 	flags = PasteboardSynchronize(clip.apple);
 	if((flags&kPasteboardModified) || !(flags&kPasteboardClientIsOwner)){
 		fprint(2, "apple pasteboard cannot assert ownership\n");
+		free(r);
 		qunlock(&clip.lk);
 		return;
 	}
 	cfdata = CFDataCreate(kCFAllocatorDefault,
-		(uchar*)clip.rbuf, runestrlen(clip.rbuf)*2);
+		(uchar*)r, runestrlen(r)*2);
+	free(r);
 	if(cfdata == nil){
 		fprint(2, "apple pasteboard cfdatacreate failed\n");
 		qunlock(&clip.lk);

src/cmd/snarfer/snarfer.c

@@ -54,11 +54,8 @@ AUTOFRAMEWORK(Carbon)
 #undef time
 AUTOLIB(draw)	/* to cause link of X11 */
 
-enum {
-	SnarfSize = 65536
-};
-char snarf[3*SnarfSize+1];
-Rune rsnarf[SnarfSize+1];
+char *snarf;
+Rune *rsnarf;
 XDisplay *xdisplay;
 XWindow drawable;
 Atom xclipboard;
@@ -98,6 +95,7 @@ main(int argc, char **argv)
 		break;
 	}ARGEND
 
+	snarf = strdup("");
 	if((xdisplay = XOpenDisplay(nil)) == nil)
 		sysfatal("XOpenDisplay: %r");
 	drawable = XCreateWindow(xdisplay, DefaultRootWindow(xdisplay),
@@ -256,18 +254,16 @@ xgetsnarf(void)
 		return nil;
 	/* get the property */
 	data = nil;
-	XGetWindowProperty(xd, drawable, prop, 0, SnarfSize/sizeof(ulong), 0,
+	XGetWindowProperty(xd, drawable, prop, 0, (len+3)/4, 0,
 		AnyPropertyType, &type, &fmt, &len, &dummy, &xdata);
 	if(xdata == nil || (type != XA_STRING && type != xutf8string) || len == 0){
 		if(xdata)
 			XFree(xdata);
 		return nil;
 	}
-	if(strlen((char*)xdata) >= SnarfSize){
-		XFree(xdata);
-		return nil;
-	}
-	strcpy(snarf, (char*)xdata);
+	free(snarf);
+	snarf = strdup((char*)xdata);
+	XFree(xdata);
 	return snarf;
 }
 
@@ -286,8 +282,16 @@ appleputsnarf(void)
 #ifdef __APPLE__
 	CFDataRef cfdata;
 	PasteboardSyncFlags flags;
+	int n;
 
-	runesnprint(rsnarf, nelem(rsnarf), "%s", snarf);
+	if(snarf == nil)
+		return;
+	n = utflen(snarf) + 1;
+	free(rsnarf);
+	rsnarf = malloc(n * sizeof(Rune));
+	if(rsnarf == nil)
+		return;
+	runesnprint(rsnarf, n, "%s", snarf);
 	if(PasteboardClear(appleclip) != noErr){
 		fprint(2, "apple pasteboard clear failed\n");
 		return;