VPLAY-11969 GetTextTrackInfo returns stale information

If the text track is changed without a re-tune then priv_aamps
mPreferredTextTrack, and stream abstractions mTextTrackIndex are not
updated to reflect the current track

The manifest url can be set to null due to an issue with passing the
same string into cache handler methods as multiple params by reference.

The specified language set via SetTextTrack() is ignored in perference to the
prefferedTextLanguage list.

Author: DomSyna

AampCacheHandler.cpp

@@ -59,22 +59,14 @@ void AampCacheHandler::StopPlaylistCache( void )
 	mCondVar.notify_one();
 }
 
-bool AampCacheHandler::RetrieveFromPlaylistCache( const std::string &url, AampGrowableBuffer* buffer, std::string& effectiveUrl, AampMediaType mediaType  )
+bool AampCacheHandler::RetrieveFromPlaylistCache(std::string url, AampGrowableBuffer* buffer, std::string& effectiveUrl, AampMediaType mediaType)
 {
 	bool ret = false;
 	std::lock_guard<std::mutex> lock(mCacheAccessMutex);
 	AampCachedData *cachedData = mPlaylistCache.Find(url);
-	if( cachedData )
+	if (cachedData)
 	{
-		// Create a local copy to prevent aliasing bug when url and effectiveUrl reference the same string
-		// This can happen when callers pass GetManifestUrl() for both parameters
-		std::string urlCopy = url;
-
-		effectiveUrl = cachedData->effectiveUrl;
-		if (effectiveUrl.empty())
-		{
-			effectiveUrl = urlCopy;
-		}
+		effectiveUrl = cachedData->effectiveUrl.empty() ? url : cachedData->effectiveUrl;
 		buffer->Clear();
 		buffer->AppendBytes(cachedData->buffer->GetPtr(), cachedData->buffer->GetLen());
 		// below fails when playing an HLS playlist directly, then seeking or retuning
@@ -123,26 +115,15 @@ void AampCacheHandler::InsertToInitFragCache( const std::string &url, const Aamp
 	mInitFragmentCache.Insert( url, buffer, effectiveUrl, mediaType );
 }
 
-bool AampCacheHandler::RetrieveFromInitFragmentCache(const std::string &url, AampGrowableBuffer* buffer, std::string& effectiveUrl)
+bool AampCacheHandler::RetrieveFromInitFragmentCache(std::string url, AampGrowableBuffer* buffer, std::string& effectiveUrl)
 {
 	bool ret = false;
 	std::lock_guard<std::mutex> lock(mCacheAccessMutex);
 	AampCachedData *cachedData = mInitFragmentCache.Find(url);
 	if (cachedData)
 	{
 		std::shared_ptr<AampGrowableBuffer> buf = cachedData->buffer;
-
-		// Create a local copy to prevent aliasing bug when url and effectiveUrl reference the same string
-		std::string urlCopy = url;
-
-		if (cachedData->effectiveUrl.empty())
-		{
-			effectiveUrl = urlCopy;
-		}
-		else
-		{
-			effectiveUrl = cachedData->effectiveUrl;
-		}
+		effectiveUrl = cachedData->effectiveUrl.empty() ? url : cachedData->effectiveUrl;
 		buffer->Clear();
 		buffer->AppendBytes(buf->GetPtr(), buf->GetLen());
 		AAMPLOG_INFO("%s %s found", GetMediaTypeName(cachedData->mediaType), url.c_str());

AampCacheHandler.h

@@ -447,7 +447,7 @@ class AampCacheHandler
 	 *   @param[out] effectiveUrl - Final URL
 	 *   @return true: found, false: not found
 	 */
-	bool RetrieveFromPlaylistCache( const std::string &url, AampGrowableBuffer* buffer, std::string& effectiveUrl, AampMediaType mediaType );
+	bool RetrieveFromPlaylistCache(std::string url, AampGrowableBuffer* buffer, std::string& effectiveUrl, AampMediaType mediaType);
 
 	/**
 	 * @brief Remove playlist from cache
@@ -493,7 +493,7 @@ class AampCacheHandler
 	 *
 	 *   @return true: found, false: not found
 	 */
-	bool RetrieveFromInitFragmentCache(const std::string &url, AampGrowableBuffer* buffer, std::string& effectiveUrl);
+	bool RetrieveFromInitFragmentCache(std::string url, AampGrowableBuffer* buffer, std::string& effectiveUrl);
 
 	/**
 	*   @brief set max initialization fragments allowed in cache (per track)