5 files changed, 17 insertions, 2 deletions
diff --git a/graphics/decoders/iff.cpp b/graphics/decoders/iff.cpp
index 7b37969fc1..fe27258d28 100644
--- a/graphics/decoders/iff.cpp
+++ b/graphics/decoders/iff.cpp
@@ -30,6 +30,10 @@ namespace Graphics {
 IFFDecoder::IFFDecoder() {
 	_surface = 0;
 	_palette = 0;
+	
+	// these 2 properties are not reset by destroy(), so the default is set here.
+	_numRelevantPlanes = 8;
+	_pixelPacking = false;
 
 	destroy();
 }
@@ -54,8 +58,6 @@ void IFFDecoder::destroy() {
 	_paletteRanges.clear();
 	_type = TYPE_UNKNOWN;
 	_paletteColorCount = 0;
-	_numRelevantPlanes = 8;
-	_pixelPacking = false;
 }
 
 bool IFFDecoder::loadStream(Common::SeekableReadStream &stream) {
diff --git a/graphics/decoders/iff.h b/graphics/decoders/iff.h
index beac62e519..37cb4b38c1 100644
--- a/graphics/decoders/iff.h
+++ b/graphics/decoders/iff.h
@@ -85,6 +85,8 @@ public:
 	/**
 	* The number of planes to decode, also determines the pixel packing if _packPixels is true.
 	* 8 == decode all planes, map 1 pixel in 1 byte. (default, no packing even if _packPixels is true)
+	*
+	* NOTE: this property must be reset manually, and is not reset by a call to destroy().
 	*/
 	void setNumRelevantPlanes(const uint8 numRelevantPlanes) { _numRelevantPlanes = numRelevantPlanes; }
 
@@ -94,6 +96,8 @@ public:
 	* 2 == decode first 2 planes, pack 4 pixels in 1 byte. This makes _surface->w 1/4th of _header.width
 	* 4 == decode first 4 planes, pack 2 pixels in 1 byte. This makes _surface->w half of _header.width
 	* Packed bitmaps won't have a proper surface format since there is no way to tell it to use 1, 2 or 4 bits per pixel
+	*
+	* NOTE: this property must be reset manually, and is not reset by a call to destroy().
 	*/
 	void setPixelPacking(const bool pixelPacking) { _pixelPacking = pixelPacking; }
 private:
diff --git a/graphics/decoders/image_decoder.h b/graphics/decoders/image_decoder.h
index 49e31c6e3a..a39a9a1493 100644
--- a/graphics/decoders/image_decoder.h
+++ b/graphics/decoders/image_decoder.h
@@ -44,6 +44,9 @@ public:
 
 	/**
 	 * Load an image from the specified stream
+	 * 
+	 * loadStream() should implicitly call destroy() to free the memory
+	 * of the last loadStream() call.
 	 *
 	 * @param stream the input stream
 	 * @return whether loading the file succeeded
@@ -54,6 +57,9 @@ public:
 
 	/**
 	 * Destroy this decoder's surface and palette
+	 *
+	 * This should be called by a loadStream() implementation as well
+	 * as the destructor.
 	 */
 	virtual void destroy() = 0;
 
diff --git a/graphics/decoders/tga.cpp b/graphics/decoders/tga.cpp
index a9f136d238..bc27f18a49 100644
--- a/graphics/decoders/tga.cpp
+++ b/graphics/decoders/tga.cpp
@@ -50,6 +50,8 @@ void TGADecoder::destroy() {
 }
 
 bool TGADecoder::loadStream(Common::SeekableReadStream &tga) {
+	destroy();
+
 	byte imageType, pixelDepth;
 	bool success;
 	success = readHeader(tga, imageType, pixelDepth);
diff --git a/graphics/decoders/tga.h b/graphics/decoders/tga.h
index d8ccf8f766..5b1e87d4c5 100644
--- a/graphics/decoders/tga.h
+++ b/graphics/decoders/tga.h
@@ -26,6 +26,7 @@
 /*
  * TGA decoder used in engines:
  *  - wintermute
+ *  - zvision
  */
 
 #ifndef GRAPHICS_DECODERS_TGA_H