cr lf only gets expanded if there is room for it.

and int 21: 06 return al=0 if no key


Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@537

src/dos/dev_con.h

@@ -42,7 +42,7 @@ bool device_CON::Read(Bit8u * data,Bit16u * size) {
 		case 13:
 			data[count++]=0x0D;
 			if (*size>count) data[count++]=0x0A;
-			else cache=0x0A;
+			//else cache=0x0A;  // it's only expanded if there is room for it.
 			*size=count;
 			reg_ax=oldax;
 			return true;

src/dos/dos.cpp

@@ -68,6 +68,7 @@ static Bitu DOS_21Handler(void) {
 			{	
 //TODO Make this better according to standards
 				if (!DOS_GetSTDINStatus()) {
+					reg_al=0;
 					CALLBACK_SZF(true);
 					break;
 				}