Limit size of windows and don't print outside screen region

shell.asm

@@ -148,17 +148,21 @@ paint:
 	mov bp, [si + window.y]
 	mov si, [si + window.data]
 
+	add dx, bp
+	cmp dx, ROWS
+	jle .no_clipping_height
+	mov dx, ROWS
+	.no_clipping_height:
+	sub dx, bp
+
 	mov cx, bx
 	add cx, di
 	cmp cx, COLUMNS
-	jle .no_clipping
+	jle .no_clipping_width
 	mov cx, COLUMNS
+	.no_clipping_width:
 	sub cx, di
-	jmp .clipping_done
 
-	.no_clipping:
-	mov cx, bx
-	.clipping_done:
 	call PONYDOS_SEG:SYS_DRAW_RECT
 
 	ret
@@ -253,6 +257,8 @@ resize:
 	jc .x
 	cmp dx, WINDOW_MIN_HEIGHT
 	jl .x
+	cmp dx, ROWS
+	jg .x
 
 	mov [si + window.y], bx
 	mov [si + window.height], dx
@@ -263,6 +269,8 @@ resize:
 	jc .done
 	cmp dx, WINDOW_MIN_WIDTH
 	jl .done
+	cmp dx, COLUMNS
+	jg .done
 
 	mov [si + window.x], cx
 	mov [si + window.width], dx