autopickup exceptions bit

My previous change underwent a last minute simplification that changed
behavior.  This puts things back to how I intended:  at the "add new
autopickup exception pattern" prompt, empty input returns you to the upper
add/list/remove/exit menu and ESC returns you past that (back to play or to
other pending 'O' changes, if any).  The previous change accidentally made
empty input behave the same as ESC.

src/options.c

@@ -3046,16 +3046,20 @@ boolean setinitial,setfromfile;
 	} else if (opt_idx == 0) {	/* add new */
 		getlin("What new autopickup exception pattern?", &apebuf[1]);
 		mungspaces(&apebuf[1]);	/* regularize whitespace */
-		if (apebuf[1] && apebuf[1] != '\033') {
-		    apebuf[0] = '\"';
-		    /* guarantee room for \" prefix and \"\0 suffix;
-		       -2 is good enough for apebuf[] but -3 makes
-		       sure the whole thing fits within normal BUFSZ */
-		    apebuf[sizeof apebuf - 3] = '\0';
-		    Strcat(apebuf, "\"");
-		    add_autopickup_exception(apebuf);
+		if (apebuf[1] == '\033') {
+		    ;	/* fall through to function exit */
+		} else {
+		    if (apebuf[1]) {
+			apebuf[0] = '\"';
+			/* guarantee room for \" prefix and \"\0 suffix;
+			   -2 is good enough for apebuf[] but -3 makes
+			   sure the whole thing fits within normal BUFSZ */
+			apebuf[sizeof apebuf - 3] = '\0';
+			Strcat(apebuf, "\"");
+			add_autopickup_exception(apebuf);
+		    }
 		    goto ape_again;
-		} /* else fall through to function exit */
+		}
 	} else {	/* list or remove */
 		tmpwin = create_nhwindow(NHW_MENU);
 		start_menu(tmpwin);