From 80160eff00e7a02584bf2d84d46a7a4eb6d49c81 Mon Sep 17 00:00:00 2001
From: sherlock-zhouyh <15151851377@163.com>
Date: Fri, 29 Oct 2021 22:14:07 +0800
Subject: [PATCH] Quit while src file increased during transfer because it will
 make transfer process stuck in dead loop.

---
 src/FileCopy.cc | 8 ++++++++
 src/FileCopy.h  | 1 +
 2 files changed, 9 insertions(+)

diff --git a/src/FileCopy.cc b/src/FileCopy.cc
index ead65a2e0..31d4e0664 100644
--- a/src/FileCopy.cc
+++ b/src/FileCopy.cc
@@ -1137,6 +1137,7 @@ void FileCopyPeerFA::OpenSession()
 	 debug((10,"copy dst: seek past eof (seek_pos=%lld, size=%lld)\n",
 		  (long long)seek_pos,(long long)e_size));
 	 eof=true;
+	 fileincreased=true;
 	 if(date==NO_DATE || date==NO_DATE_YET)
 	    return;
       }
@@ -1284,6 +1285,12 @@ int FileCopyPeerFA::Put_LL(const char *buf,int len)
    if(session->IsClosed())
       OpenSession();
 
+   if(fileincreased)
+   {
+      SetError(_("file size increased during transfer"));
+      return -1;
+   }
+
    off_t io_at=pos; // GetRealPos can alter pos, save it.
    if(GetRealPos()!=io_at)
       return 0;
@@ -1352,6 +1359,7 @@ void FileCopyPeerFA::Init()
 {
    get_delay=0;
    fxp=false;
+   fileincreased=false;
    redirections=0;
    can_seek=true;
    can_seek0=true;
diff --git a/src/FileCopy.h b/src/FileCopy.h
index af978809b..5a9e4cf59 100644
--- a/src/FileCopy.h
+++ b/src/FileCopy.h
@@ -335,6 +335,7 @@ class FileCopyPeerFA : public FileCopyPeer
    FileSet info;
 
    bool fxp;   // FXP (ftp<=>ftp copy) active
+   bool fileincreased;
 
    UploadState upload_state;
    int redirections;