Fixed #2260 Reading end of file on old GFX format (1.x)

Fixed #2260 DefineExternalImage on old GFX format (1.x)

libsrc/ffdec_lib/src/com/jpexs/helpers/FakeMemoryInputStream.java

@@ -0,0 +1,89 @@
+/*
+ *  Copyright (C) 2010-2023 JPEXS, All rights reserved.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.0 of the License, or (at your option) any later version.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.
+ */
+package com.jpexs.helpers;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Special MemoryInputStream that is not a MemoryInputStream in fact.
+ * Input stream to handle some edge cases
+ * @author JPEXS
+ */
+public class FakeMemoryInputStream extends MemoryInputStream {
+
+    private long pos;
+
+    private final int maxLength;
+    
+    private final InputStream is;
+    
+    public FakeMemoryInputStream(InputStream is) throws IOException {
+        super(new byte[0]);
+        this.maxLength = Integer.MAX_VALUE; 
+        this.is = is;
+    }
+
+    @Override
+    public byte[] getAllRead() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public long getPos() {
+        return pos;
+    }
+
+    @Override
+    public void seek(long pos) throws IOException {
+        if (pos < 0) {
+            throw new IOException("Seek to negative position");
+        }
+        this.pos = pos;
+    }
+
+    @Override
+    public synchronized void reset() throws IOException {
+        seek(0);
+    }
+
+    @Override
+    public int read() throws IOException {
+        if (pos < maxLength) {            
+            pos++;
+            return is.read();
+        }
+
+        return -1;
+    }
+
+    @Override
+    public int read(byte[] bytes) throws IOException {
+        if (pos < maxLength) {
+            int readCount = is.read(bytes);
+            pos += readCount;
+            return readCount;
+        }
+
+        return -1;
+    }
+
+    @Override
+    public int available() throws IOException {
+        return is.available();
+    }
+}