Index: src/ch/FeedbackReplaceDlg.cpp
===================================================================
diff -u -N -rb14efbdfe0eb5c1164b8e5f605b7e9f88fbda25a -rc6022cc2c68d1f286097697f4ba65098b92db222
--- src/ch/FeedbackReplaceDlg.cpp	(.../FeedbackReplaceDlg.cpp)	(revision b14efbdfe0eb5c1164b8e5f605b7e9f88fbda25a)
+++ src/ch/FeedbackReplaceDlg.cpp	(.../FeedbackReplaceDlg.cpp)	(revision c6022cc2c68d1f286097697f4ba65098b92db222)
@@ -156,6 +156,17 @@
 	dtTemp = m_rDstFile.GetLastWriteTime().GetAsFiletime();
 	fmt.SetParam(_T("%datemod"), dtTemp.Format(LOCALE_NOUSEROVERRIDE, LANG_USER_DEFAULT));
 	m_ctlDstDate.SetWindowText(fmt);
+
+	// button captions
+	CWnd* pAppendButton = GetDlgItem(IDC_COPY_REST_BUTTON);
+	if(pAppendButton)
+	{
+		if(m_rDstFile.GetLength64() > m_rSrcFile.GetLength64())
+		{
+			CString strAltButtonCaption = rManager.LoadString(IDS_BUTTON_TRUNCATE_STRING);
+			pAppendButton->SetWindowText(strAltButtonCaption);
+		}
+	}
 }
 
 void CFeedbackReplaceDlg::RefreshImages()
Index: src/ch/ch.rc
===================================================================
diff -u -N -r8a809e7eb52d42ad31789613fe375ba5a1e30a7d -rc6022cc2c68d1f286097697f4ba65098b92db222
--- src/ch/ch.rc	(.../ch.rc)	(revision 8a809e7eb52d42ad31789613fe375ba5a1e30a7d)
+++ src/ch/ch.rc	(.../ch.rc)	(revision c6022cc2c68d1f286097697f4ba65098b92db222)
@@ -416,8 +416,8 @@
     EDITTEXT        IDC_DST_FILESIZE_EDIT,54,116,251,12,ES_AUTOHSCROLL | ES_READONLY | NOT WS_BORDER
     EDITTEXT        IDC_DST_MODIFIEDDATE_EDIT,54,127,251,12,ES_AUTOHSCROLL | ES_READONLY | NOT WS_BORDER
     LTEXT           "File you are trying to copy already exists. What do you want to do?",IDC_INFO_STATIC,7,7,305,15
-    ICON            "",IDC_SRC_ICON_STATIC,20,38,21,20
-    ICON            "",IDC_DST_ICON_STATIC,20,102,21,20
+    ICON            "",IDC_SRC_ICON_STATIC,20,38,20,20
+    ICON            "",IDC_DST_ICON_STATIC,20,102,20,20
     GROUPBOX        "Source file",IDC_SRCFILE_STATIC,7,20,305,58
     GROUPBOX        "Destination file",IDC_DSTFILE_STATIC,7,83,305,58
 END
@@ -1167,13 +1167,18 @@
     IDS_BDTREE_STRING       "Tree"
     IDS_BDNDSCONTAINER_STRING "NDS Container"
     IDS_INFO_PATH_STRING    "Location: %pathname"
-    IDS_INFO_FILE_STRING    "File: %filename"
     IDS_INFO_SIZE_STRING    "Size: %size"
     IDS_INFO_MODIFIED_STRING "Modified: %datemod"
 END
 
 STRINGTABLE
 BEGIN
+    IDS_INFO_REASON_STRING  "Reason: %reason"
+    IDS_INFO_FILE_STRING    "File: %filename"
+END
+
+STRINGTABLE
+BEGIN
     IDS_INFO_TWO_FILE_STRING 
                             "Source file: %filename\nDestination file: %dstfilename"
     IDS_OK_STRING           "&OK"
@@ -1213,13 +1218,9 @@
     IDS_ALWAYS_SHOW_STRING  "Always show"
     IDS_HIDE_AND_REGISTER   "Hide and register extension"
     IDS_HIDE_AND_DONT_REGISTER "Hide and do not register extension"
+	IDS_BUTTON_TRUNCATE_STRING "&Truncate"
 END
 
-STRINGTABLE
-BEGIN
-    IDS_INFO_REASON_STRING  "Reason: %reason"
-END
-
 #endif    // English (United States) resources
 /////////////////////////////////////////////////////////////////////////////
 
Index: src/ch/resource.h
===================================================================
diff -u -N -r8a809e7eb52d42ad31789613fe375ba5a1e30a7d -rc6022cc2c68d1f286097697f4ba65098b92db222
--- src/ch/resource.h	(.../resource.h)	(revision 8a809e7eb52d42ad31789613fe375ba5a1e30a7d)
+++ src/ch/resource.h	(.../resource.h)	(revision c6022cc2c68d1f286097697f4ba65098b92db222)
@@ -678,6 +678,7 @@
 #define IDS_EMPTYSUBTASKNAME_STRING     21554
 #define IDS_STATUS_LOADERROR_STRING     21555
 #define IDS_EXPORTING_TASK_FAILED       21556
+#define IDS_BUTTON_TRUNCATE_STRING      21557
 #define ID_POPUP_SHOW_STATUS            32773
 #define ID_POPUP_TIME_CRITICAL          32774
 #define ID_POPUP_HIGHEST                32775
Index: src/libchcore/TSubTaskCopyMove.cpp
===================================================================
diff -u -N -re8f31b0f922b402878356e130c866c4f3682a7f5 -rc6022cc2c68d1f286097697f4ba65098b92db222
--- src/libchcore/TSubTaskCopyMove.cpp	(.../TSubTaskCopyMove.cpp)	(revision e8f31b0f922b402878356e130c866c4f3682a7f5)
+++ src/libchcore/TSubTaskCopyMove.cpp	(.../TSubTaskCopyMove.cpp)	(revision c6022cc2c68d1f286097697f4ba65098b92db222)
@@ -665,6 +665,13 @@
 			return TSubTaskBase::eSubResult_Continue;
 		}
 
+		// ullSeekTo contains the seek position in destination file; in case the destination is already
+		// larger than source file all we can do is to perform truncation of destination file to the size of
+		// source file.
+		// NOTE: the truncation that will be the result of the following assignment might cause the end of destination file
+		// to be overwritten by the end of source file.
+		ullSeekTo = std::min(ullSeekTo, fsNewSize);
+
 		// seek to the position where copying will start
 		file_size_t fsMoveTo = spFileDst->GetSeekPositionForResume(ullSeekTo);