crash fix for broken files

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@6811 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/media/plugins/aiff_reader/aiff_reader.cpp

@@ -89,6 +89,10 @@ aiffReader::Sniff(int32 *streamCount)
 			return B_ERROR;
 		}
 		pos += sizeof(chunk);
+		if (UINT32(chunk.chunk_size) == 0) {
+			TRACE("aiffReader::Sniff: Error: chunk of size 0 found\n");
+			return B_ERROR;
+		}
 		switch (UINT32(chunk.chunk_id)) {
 			case FOURCC('C','O','M','M'):
 			{

src/add-ons/media/plugins/avi_reader/libOpenDML/OpenDMLParser.cpp

@@ -143,6 +143,11 @@ OpenDMLParser::Parse(BPositionIO *source)
 		pos += 4;
 		size = AVI_UINT32(temp);
 
+		if (size == 0) {
+			TRACE("OpenDMLParser::Parse: Error: chunk of size 0 found\n");
+			goto err;
+		}
+		
 		if (fourcc == FOURCC('J','U','N','K')) {
 			TRACE("OpenDMLParser::Parse: JUNK chunk ignored, size: %lu bytes\n", size);
 			goto cont;

src/add-ons/media/plugins/wav_reader/WavReaderPlugin.cpp

@@ -100,6 +100,10 @@ WavReader::Sniff(int32 *streamCount)
 			return B_ERROR;
 		}
 		pos += sizeof(chunk);
+		if (UINT32(chunk.len) == 0) {
+			TRACE("WavReader::Sniff: Error: chunk of size 0 found\n");
+			return B_ERROR;
+		}
 		switch (UINT32(chunk.fourcc)) {
 			case FOURCC('f','m','t',' '):
 				if (UINT32(chunk.len) >= sizeof(format)) {