0004002: When Copy operation is broken due to "Unexpected network error" (0x3B), [Retry] button will restart to copy the file from begin - MantisBT

ID	Project	Category	View Status	Date Submitted	Last Update

0004002	Far Manager	Copy/Move	public	2023-08-17 17:12	2023-08-31 20:02

Reporter	alexfbg	Assigned To
Priority	normal	Severity	major	Reproducibility	always
Status	new	Resolution	open
Platform	x64	OS	Windows	OS Version	2012
Product Version	3.0

Summary	0004002: When Copy operation is broken due to "Unexpected network error" (0x3B), [Retry] button will restart to copy the file from begin
Description	When Copy operation is broken due to "An unexpected network error occured" (0x0000003B), [Retry] button will restart to copy the file from beginning! Not from the offset, where file is stopped to copy.
Steps To Reproduce	Steps to reproduce: 1) Let's place a big file (to understand why this is important) like 500 GB binary.dat to a network disk that is mounted to some drive letter like V: 2) Start to copy V:\binary.dat to a local drive for example, D:\TEMP 3) Wait until 20-30 or 50% is already copied. 4) Produce a network error (0x3B) or deattach lan cable (probably, not tested) 5) You will get an error like "Cannot copy "binary.dat" to "D:\TEMP\binary.dat"" and selection: [Retry] [ Skip ] [ Skip All ] [ Cancel ] 6) Fix network error and/or reattach lan cable 7) Select [Retry] button to continue copying the file Current behavior: All copy progress will be back to zero and file will be copied from the very beginning, zero offset (!). Arghhh!!! Expected behavior: 1) FAR know offset where it is stopped to write to the destination path (last written block to destination, i.e. you may use even filesize()). 2) FAR seeks to the same offset on the source path and continue to read block from this offset doing seek to this offset 3) FAR will continue at the unexpected break location, NOT from the start of file. And you will be able to do not wait for a 5 hours again.
Tags	copy, network error

Build

HaRT 2023-08-17 23:15 reporter bugnote:0017448	What's the state of the “Use system copy routine” option in FAR's “System settings”? Does the issue repro if the option is toggled?

alexfbg 2023-08-18 18:04 reporter bugnote:0017450 Last edited: 2023-08-18 18:15	Additional operation with the same effect (not only network error): 0x00000017 - Data error (cyclic redundancy check). If you had got this error and click on [Retry] button, FAR is starting copying file from zero offset! I had got this now at 120GB file at 76% of copy process... That's unbelievable!

alexfbg 2023-08-18 18:05 reporter bugnote:0017451	What's the state of the “Use system copy routine” option in FAR's “System settings”? Does the issue repro if the option is toggled? HaRT FAR option is: [x] Use system copy routine < enabled So, the problem is here? I need to disable it to use internal FAR procedure? What are the other differences? (Is any doc where differences are written)?

alexfbg 2023-08-18 18:11 reporter bugnote:0017453	From the help: Use system copy routine Use the file copy functions provided by the operating system instead of internal file copy implementation. It can be useful on NTFS, because the system function (CopyFileEx) copies extended file attributes. On the other hand, when using the system function, the possibility of "smart" copying of sparse files is not available. Help Is this all difference? And the main question: why internal FAR procedure can't copy extended NTFS attributes too (if required)? Why original function is need at all? Why it does not fully "copied" and modified for best use (for example, to retry from the saved position)? (But without losing some of the Windows functions).

alexfbg 2023-08-18 18:14 reporter bugnote:0017454	Does the issue repro if the option is toggled? HaRT Oh, sorry, I read this wrong. The issue occurs when this option is ENABLED (toggled). I did not tested with disabled "[ ] Use system copy routine". This ticket is a result of working with enabled system routine: "[x] Use system copy routine"

HaRT 2023-08-18 18:47 reporter bugnote:0017455	“Toggled” does not mean “enabled”, it means “value changed to its opposite”. So, to better diagnose the issue please test with the option disabled. If/when any of developers who is familiar with that code looks into this issue, to know whether the option makes any difference will be useful.

DrKnS 2023-08-31 20:02 administrator bugnote:0017478	[Retry] button will restart to copy the file from beginning! This is how CopyFileEx works. It is annoying, I know. I wasted an hour or so myself the other day in exactly the same situation. If your network is prone to "unexpected errors", don't use the system copy routine. why internal FAR procedure can't copy extended NTFS attributes too (if required)? Because we have rather limited resources. You are always welcome to implement it yourself and open a pull request. Why it does not fully "copied" and modified for best use Because Windows is a commercial closed source OS and the source code of this function is not available, so we can only guess what it does and how. I'll keep this issue open to explore some alternatives in the future, e.g. optionally using COPY_FILE_RESTARTABLE flag.

Date Modified	Username	Field	Change
2023-08-17 17:12	alexfbg	New Issue
2023-08-17 17:12	alexfbg	Tag Attached: copy
2023-08-17 17:12	alexfbg	Tag Attached: network error
2023-08-17 23:15	HaRT	Note Added: 0017448
2023-08-18 18:04	alexfbg	Note Added: 0017450
2023-08-18 18:05	alexfbg	Note Added: 0017451
2023-08-18 18:11	alexfbg	Note Added: 0017453
2023-08-18 18:14	alexfbg	Note Added: 0017454
2023-08-18 18:15	alexfbg	Note Edited: 0017450
2023-08-18 18:47	HaRT	Note Added: 0017455
2023-08-31 20:02	DrKnS	Note Added: 0017478