tahoe cp alias1:dir1/fname alias1:dir2/fname . overwrites one of the files #2447

New Issue

zooko · 2015-06-09T22:13:19Z

zooko commented

2015-06-09 22:13:19 +00:00

I just did tahoe cp alias1:dir1/fname alias1:dir2/fname .. It probably should have done something like what unix cp does in this case:

$ cp dir1/fname dir2/fname  .
cp: will not overwrite just-created ‘./fname’ with ‘dir2/fname’

but instead it did this:

$ tahoe cp alias1:dir1/fname alias1:dir2/fname .
Success: files copied

I just did `tahoe cp alias1:dir1/fname alias1:dir2/fname .`. It probably should have done something like what unix cp does in this case: ``` $ cp dir1/fname dir2/fname . cp: will not overwrite just-created ‘./fname’ with ‘dir2/fname’ ``` but instead it did this: ``` $ tahoe cp alias1:dir1/fname alias1:dir2/fname . Success: files copied ```

zooko added the

labels 2015-06-09 22:13:19 +00:00

zooko added this to the undecided milestone 2015-06-09 22:13:19 +00:00

warner commented

2015-06-10 04:07:41 +00:00

The /bin/cp on OS-X 10.10 (which claims "The cp command is expected to be POSIX.2 compatible") silently uses the second copy, just like tahoe currently does:

% mkdir dir1
% echo one >dir1/fname
% mkdir dir2
% echo two >dir2/fname
% cp dir1/fname dir2/fname .
% cat fname
two
%

My linux box complains with the same error you listed.

The /bin/cp on OS-X 10.10 (which claims "The cp command is expected to be POSIX.2 compatible") silently uses the second copy, just like tahoe currently does: ``` % mkdir dir1 % echo one >dir1/fname % mkdir dir2 % echo two >dir2/fname % cp dir1/fname dir2/fname . % cat fname two % ``` My linux box complains with the same error you listed.

daira commented

2015-06-10 10:50:10 +00:00

I think the Linux behaviour and error message is confusing -- I don't see how it's better to write the first file than to write the second file.

I think we should instead not write any file, and say in the error message that we haven't done so because there are duplicate filenames.

I think the Linux behaviour and error message is confusing -- I don't see how it's better to write the first file than to write the second file. I think we should instead not write any file, and say in the error message that we haven't done so because there are duplicate filenames.

tahoe-lafs modified the milestone from undecided to 1.11.0

2015-06-10 10:50:10 +00:00

warner commented

2015-06-15 04:34:39 +00:00

I checked a couple of versions back: tahoe-1.9.0 and 1.10.0 both behave like trunk and OS-X (second file silently wins).

I'm +0 with daira's error-out suggestion for 1.11. I'm -0 for landing this in 1.10.1, just because we're so darn close :). I'm sympathetic to Zooko's argument that prolonging this behavior will increase the number of scripts and tools that accidentally depend upon the unusual (compared to linux, not compared to OS-X) behavior, but I'm also swayed by Daira's argument that it's been this way long enough that one more release isn't going to make much of a difference.

I checked a couple of versions back: tahoe-1.9.0 and 1.10.0 both behave like trunk and OS-X (second file silently wins). I'm +0 with daira's error-out suggestion for 1.11. I'm -0 for landing this in 1.10.1, just because we're so darn close :). I'm sympathetic to Zooko's argument that prolonging this behavior will increase the number of scripts and tools that accidentally depend upon the unusual (compared to linux, not compared to OS-X) behavior, but I'm also swayed by Daira's argument that it's been this way long enough that one more release isn't going to make much of a difference.

zooko commented

2015-06-16 17:25:18 +00:00

I have a failing unit test for this, yay: https://github.com/zooko/tahoe-lafs/commit/26aef8eab2578969a4ec52abd19bbd32537b8bc5

I have a failing unit test for this, yay: <https://github.com/zooko/tahoe-lafs/commit/26aef8eab2578969a4ec52abd19bbd32537b8bc5>

tahoe-lafs modified the milestone from 1.11.0 to 1.10.2

2015-07-17 21:52:52 +00:00

warner self-assigned this 2015-07-21 16:52:54 +00:00

Brian Warner <warner@lothar.com> commented

2015-07-29 00:40:37 +00:00

In /tahoe-lafs/trac-2024-07-25/commit/98ab848cdae2743753d48dda2c34f081496f7e80:

cp: error on target-filename collisions, rather than overwrite

Closes ticket:2447

In [/tahoe-lafs/trac-2024-07-25/commit/98ab848cdae2743753d48dda2c34f081496f7e80](/tahoe-lafs/trac-2024-07-25/commit/98ab848cdae2743753d48dda2c34f081496f7e80): ``` cp: error on target-filename collisions, rather than overwrite Closes ticket:2447 ```

tahoe-lafs added the

fixed

label 2015-07-29 00:40:37 +00:00

tahoe-lafs closed this issue

2015-07-29 00:40:37 +00:00

Sign in to join this conversation.