Index: src/libchcore/TLocalFilesystem.cpp
===================================================================
diff -u -r2fe97a93f21771d75901d4b6559057d1ea055104 -r16df8fcf9d5b3317338aece64762771419beaf4a
--- src/libchcore/TLocalFilesystem.cpp	(.../TLocalFilesystem.cpp)	(revision 2fe97a93f21771d75901d4b6559057d1ea055104)
+++ src/libchcore/TLocalFilesystem.cpp	(.../TLocalFilesystem.cpp)	(revision 16df8fcf9d5b3317338aece64762771419beaf4a)
@@ -459,4 +459,21 @@
 	m_hFile = INVALID_HANDLE_VALUE;
 }
 
+unsigned long long TLocalFilesystemFile::GetFileSize() const
+{
+	if(!IsOpen())
+		return 0;
+
+	BY_HANDLE_FILE_INFORMATION bhfi;
+
+	if(!::GetFileInformationByHandle(m_hFile, &bhfi))
+		return 0;
+
+	ULARGE_INTEGER uli;
+	uli.HighPart = bhfi.nFileSizeHigh;
+	uli.LowPart = bhfi.nFileSizeLow;
+
+	return uli.QuadPart;
+}
+
 END_CHCORE_NAMESPACE
Index: src/libchcore/TLocalFilesystem.h
===================================================================
diff -u -ra5aa3c3cb78f3767641de2627d1a49a1dc35b429 -r16df8fcf9d5b3317338aece64762771419beaf4a
--- src/libchcore/TLocalFilesystem.h	(.../TLocalFilesystem.h)	(revision a5aa3c3cb78f3767641de2627d1a49a1dc35b429)
+++ src/libchcore/TLocalFilesystem.h	(.../TLocalFilesystem.h)	(revision 16df8fcf9d5b3317338aece64762771419beaf4a)
@@ -121,6 +121,7 @@
 	bool WriteFile(TSimpleDataBuffer& rBuffer, DWORD dwToWrite, DWORD& rdwBytesWritten);
 
 	bool IsOpen() const { return m_hFile != INVALID_HANDLE_VALUE; }
+	unsigned long long GetFileSize() const;
 
 	void Close();
 
Index: src/libchcore/TSubTaskCopyMove.cpp
===================================================================
diff -u -rd76d3ce6c8c55fa23009dbb03b8bc06f482c5b72 -r16df8fcf9d5b3317338aece64762771419beaf4a
--- src/libchcore/TSubTaskCopyMove.cpp	(.../TSubTaskCopyMove.cpp)	(revision d76d3ce6c8c55fa23009dbb03b8bc06f482c5b72)
+++ src/libchcore/TSubTaskCopyMove.cpp	(.../TSubTaskCopyMove.cpp)	(revision 16df8fcf9d5b3317338aece64762771419beaf4a)
@@ -378,13 +378,34 @@
 
 			listEmptyBuffers.push_back(spBuffer);
 
+			unsigned long long ullCITotalSize = m_tSubTaskStats.GetCurrentItemTotalSize();
+			unsigned long long ullCIProcessedSize = m_tSubTaskStats.GetCurrentItemProcessedSize();
+
+			if(ullCIProcessedSize + ulWritten > ullCITotalSize)
+			{
+				// total size changed
+				pData->spSrcFile->SetLength64(ullCIProcessedSize + ulWritten);
+				m_tSubTaskStats.IncreaseCurrentItemTotalSize(ullCIProcessedSize + ulWritten - ullCITotalSize);
+				m_tSubTaskStats.IncreaseTotalSize(ullCIProcessedSize + ulWritten - ullCITotalSize);
+			}
+
 			// new stats
 			m_tSubTaskStats.IncreaseProcessedSize(ulWritten);
 			m_tSubTaskStats.IncreaseCurrentItemProcessedSize(ulWritten);
 		}
 	}
 	while(!bLastPart);
 
+	// fix the stats for files shorter than expected
+	unsigned long long ullCITotalSize = m_tSubTaskStats.GetCurrentItemTotalSize();
+	unsigned long long ullCIProcessedSize = m_tSubTaskStats.GetCurrentItemProcessedSize();
+	if(ullCIProcessedSize < ullCITotalSize)
+	{
+		pData->spSrcFile->SetLength64(ullCIProcessedSize);
+		m_tSubTaskStats.DecreaseCurrentItemTotalSize(ullCITotalSize - ullCIProcessedSize);
+		m_tSubTaskStats.DecreaseTotalSize(ullCITotalSize - ullCIProcessedSize);
+	}
+
 	pData->bProcessed = true;
 	m_tSubTaskStats.SetCurrentItemProcessedSize(0);
 
@@ -414,6 +435,29 @@
 		return TSubTaskBase::eSubResult_Continue;
 	}
 
+	// update the source file size (it might differ from the time this file was originally scanned).
+	// NOTE: this kind of update could be also done when copying chunks of data beyond the original end-of-file,
+	//       but it would require frequent total size updates and thus - serializations).
+	// NOTE2: the by-chunk corrections of stats are still applied when copying to ensure even further size
+	//        matching; this update however still allows for better serialization management.
+	unsigned long long ullNewSize = fileSrc.GetFileSize();
+	unsigned long long ullOldSize = pData->spSrcFile->GetLength64();
+	if(ullNewSize != ullOldSize)
+	{
+		if(ullNewSize > ullOldSize)
+		{
+			m_tSubTaskStats.IncreaseTotalSize(ullNewSize - ullOldSize);
+			m_tSubTaskStats.IncreaseCurrentItemTotalSize(ullNewSize - ullOldSize);
+		}
+		else
+		{
+			m_tSubTaskStats.DecreaseTotalSize(ullOldSize - ullNewSize);
+			m_tSubTaskStats.DecreaseCurrentItemTotalSize(ullOldSize - ullNewSize);
+		}
+
+		pData->spSrcFile->SetLength64(ullNewSize);
+	}
+
 	// change attributes of a dest file
 	// NOTE: probably should be removed from here and report problems with read-only files
 	//       directly to the user (as feedback request)
Index: src/libchcore/TSubTaskStatsInfo.cpp
===================================================================
diff -u -rd76d3ce6c8c55fa23009dbb03b8bc06f482c5b72 -r16df8fcf9d5b3317338aece64762771419beaf4a
--- src/libchcore/TSubTaskStatsInfo.cpp	(.../TSubTaskStatsInfo.cpp)	(revision d76d3ce6c8c55fa23009dbb03b8bc06f482c5b72)
+++ src/libchcore/TSubTaskStatsInfo.cpp	(.../TSubTaskStatsInfo.cpp)	(revision 16df8fcf9d5b3317338aece64762771419beaf4a)
@@ -449,4 +449,28 @@
 	return m_setModifications[eMod_Added];
 }
 
+void TSubTaskStatsInfo::IncreaseTotalSize(unsigned long long ullIncreaseBy)
+{
+	boost::unique_lock<boost::shared_mutex> lock(m_lock);
+	m_ullTotalSize = m_ullTotalSize + ullIncreaseBy;
+}
+
+void TSubTaskStatsInfo::DecreaseTotalSize(unsigned long long ullDecreaseBy)
+{
+	boost::unique_lock<boost::shared_mutex> lock(m_lock);
+	m_ullTotalSize = m_ullTotalSize - ullDecreaseBy;
+}
+
+void TSubTaskStatsInfo::IncreaseCurrentItemTotalSize(unsigned long long ullIncreaseBy)
+{
+	boost::unique_lock<boost::shared_mutex> lock(m_lock);
+	m_ullCurrentItemTotalSize = m_ullCurrentItemTotalSize + ullIncreaseBy;
+}
+
+void TSubTaskStatsInfo::DecreaseCurrentItemTotalSize(unsigned long long ullDecreaseBy)
+{
+	boost::unique_lock<boost::shared_mutex> lock(m_lock);
+	m_ullCurrentItemTotalSize = m_ullCurrentItemTotalSize - ullDecreaseBy;
+}
+
 END_CHCORE_NAMESPACE
Index: src/libchcore/TSubTaskStatsInfo.h
===================================================================
diff -u -rd76d3ce6c8c55fa23009dbb03b8bc06f482c5b72 -r16df8fcf9d5b3317338aece64762771419beaf4a
--- src/libchcore/TSubTaskStatsInfo.h	(.../TSubTaskStatsInfo.h)	(revision d76d3ce6c8c55fa23009dbb03b8bc06f482c5b72)
+++ src/libchcore/TSubTaskStatsInfo.h	(.../TSubTaskStatsInfo.h)	(revision 16df8fcf9d5b3317338aece64762771419beaf4a)
@@ -82,13 +82,17 @@
 	void DecreaseProcessedSize(unsigned long long ullDecreaseBy);
 	void SetProcessedSize(unsigned long long ullProcessedSize);
 
+	void IncreaseTotalSize(unsigned long long ullIncreaseBy);
+	void DecreaseTotalSize(unsigned long long ullDecreaseBy);
 	void SetTotalSize(unsigned long long ullTotalSize);
 
 	// current item
 	void IncreaseCurrentItemProcessedSize(unsigned long long ullIncreaseBy);
 	void DecreaseCurrentItemProcessedSize(unsigned long long ullDecreaseBy);
 	void SetCurrentItemProcessedSize(unsigned long long ullProcessedSize);
 
+	void IncreaseCurrentItemTotalSize(unsigned long long ullIncreaseBy);
+	void DecreaseCurrentItemTotalSize(unsigned long long ullDecreaseBy);
 	void SetCurrentItemTotalSize(unsigned long long ullTotalSize);
 
 	unsigned long long GetCurrentItemProcessedSize() const;