bug: replclipr(2) allows line(2) to escape the window

[Nick Owens <mischief@offblast.org>]

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the attached program will draw lines in the upper left corner of rio,
regardless of the position of the rio window it is executed from.

this is not an issue with, for example, ellipse(2), otherwise you
would see an ellipse as well as lines.

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#include <u.h>
#include <libc.h>
#include <draw.h>
#include <event.h>

void
usage(void)
{
	fprint(2, "usage: %s\n", argv0);
	exits("usage");
}

Rectangle lol[] = {
	{{50, 50}, {50, 100}},
	{{50, 100}, {75, 100}},

	{{100, 50}, {100, 100}},
	{{100, 100}, {125, 100}},
	{{125, 100}, {125, 50}},
	{{125, 50}, {100, 50}},

	{{150, 50}, {150, 100}},
	{{150, 100}, {175, 100}},};

void
main(int argc, char *argv[])
{
	int i;

	ARGBEGIN{
	default:
		usage();
	}ARGEND

	initdraw(nil, nil, argv0);
	einit(Emouse);
	for(;;){
		while(ecanmouse())
			emouse();

		replclipr(screen, 0, Rect(0, 0, 9000, 9000));

		for(i = 0; i < nelem(lol); i++){
			line(screen, lol[i].min, lol[i].max, 0, 0, 5, display->black, ZP);
		}

		//draw(screen, Rect(0, 0, 9000, 9000), display->black, nil, ZP);
		ellipse(screen, Pt(100, 75), 100, 75, 3, display->black, ZP);

		flushimage(display, 1);
	}

	exits(nil);
}

void
eresized(int new)
{
	if(new && getwindow(display, Refnone) < 0)
		sysfatal("getwindow: %r");
}