3 files changed, 6 insertions(+), 2 deletions(-)

M port/devdraw.c
M port/devproc.c
M port/error.h

@@ 1531,9 1531,9 @@ drawmesg(Client *client, void *av, int n)
 			drawrectangle(&r, a+5);
 			if(!rectinrect(r, i->r))
 				error(Ereadoutside);
-			free(client->readdata);
 			c = bytesperline(r, i->ldepth);
 			c *= Dy(r);
+			free(client->readdata);
 			client->readdata = mallocz(c, 0);
 			if(client->readdata == nil)
 				error("readimage malloc failed");

@@ 361,6 361,8 @@ procread(Chan *c, void *va, long n, ulong offset)
 		rptr = (uchar*)&p->fpsave;
 		rsize = sizeof(FPsave);
 	regread:
+		if(rptr == 0)
+			error(Enoreg);
 		if(offset >= rsize)
 			return 0;
 		if(offset+n > rsize)


@@ 566,6 568,8 @@ procwrite(Chan *c, void *va, long n, ulong offset)
 			return 0;
 		if(offset+n > sizeof(Ureg))
 			n = sizeof(Ureg) - offset;
+		if(p->dbgreg == 0)
+			error(Enoreg);
 		setregisters(p->dbgreg, (char*)(p->dbgreg)+offset, va, n);
 		break;
 

@@ 51,6 51,6 @@ extern char Esoverlap[];	/* segments overlap */
 extern char Emouseset[];	/* mouse type already set */
 extern char Erecover[];		/* failed to recover fd */
 extern char Eshort[];		/* i/o count too small */
-extern char Enobitstore[];	/* out of screen memory */
 extern char Egreg[];		/* ken scheduled it */
 extern char Ebadspec[];		/* bad attach specifier */
+extern char Enoreg[];		/* process has no saved registers */