editor: abort in buildNRun if save fails

- also fix possible bug in gotoLine if
  file is empty

progs/editor.pas

@@ -137,7 +137,8 @@ end;
 procedure getScreenSize;
 var c:char;
 begin
-	(* empty keyboard buffer *)
+	(* empty keyboard buffer to make sure GetTermSize
+		can read the response from the terminal *)
 	while conavail do read(con, c);
 
 	GetTermSize(screenW, screenH);
@@ -1661,11 +1662,10 @@ end;
 
 procedure gotoLine(l:integer);
 begin
-	if l < 1 then
-		l := 1
-	else
 	if l > lineCount then
 		l := lineCount;
+	if l < 1 then
+		l := 1;
 
 	topY := l - (screenH div 2);
 	if topY < 1 then
@@ -1713,7 +1713,7 @@ var error:integer;
 begin
 	success := true;
 	if isModified then
-		save;
+		writeFile(success);
 	if success then
 	begin
 		if isAsmFile(filename) then