From ec0d890fd23bfa09a94cd1bd0e906c5b31d0b950 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jindra=20Pet=C5=99=C3=ADk?= <jindra.petrik@gmail.com>
Date: Wed, 3 Mar 2021 18:00:55 +0100
Subject: [PATCH] Fixed: Flash viewer- cyclic DefineSprite usage

---
 CHANGELOG.md                                  |  1 +
 .../decompiler/flash/timeline/Timeline.java   | 31 +++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ab94bf09a..07ed16187 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,7 @@ All notable changes to this project will be documented in this file.
 - Copying to clipboard does not support transparency
 - #1634 AS3 slot/const editor loses focus on edit button press
 - #1636 Exception after search - traitslist with not properly set abc, other ui exception
+- Flash viewer- cyclic DefineSprite usage
 
 ### Removed
 - #1631 ActiveX Flash component download in windows installer
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/timeline/Timeline.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/timeline/Timeline.java
index f65b007df..a656b32cf 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/timeline/Timeline.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/timeline/Timeline.java
@@ -306,6 +306,13 @@ public class Timeline {
                 if (characterId != -1) {
                     fl.characterId = characterId;
                 }
+                CharacterTag character = swf.getCharacter(characterId);
+                if (character instanceof DefineSpriteTag) {
+                    Stack<Integer> cyStack = new Stack<>();
+                    if (isCyclic(timelined, cyStack)) {
+                        fl.characterId = -1;
+                    }
+                }
                 if (po.flagMove()) {
                     MATRIX matrix2 = po.getMatrix();
                     if (matrix2 != null) {
@@ -1215,4 +1222,28 @@ public class Timeline {
 
         return false;
     }
+
+    private boolean isCyclic(Timelined tim, Stack<Integer> walked) {
+        for (Tag t : tim.getTags()) {
+            if (t instanceof PlaceObjectTypeTag) {
+                PlaceObjectTypeTag p = (PlaceObjectTypeTag) t;
+                int chid = p.getCharacterId();
+                if (chid != -1) {
+                    if (walked.contains(chid)) {
+                        return true;
+                    }
+                    CharacterTag character = swf.getCharacter(chid);
+                    if (character instanceof DefineSpriteTag) {
+                        walked.push(chid);
+                        if (isCyclic((DefineSpriteTag) character, walked)) {
+                            walked.pop();
+                            return true;
+                        }
+                        walked.pop();
+                    }
+                }
+            }
+        }
+        return false;
+    }
 }