Re: feature-request: git "cp" like there is git mv.

[Stefan Moch]

* Junio C Hamano <gits...@pobox.com> [2018-02-07T11:49:39-0800]:
> Stefan Moch <stefanm...@mail.de> writes:
> 
> > * Jonathan Nieder <jrnie...@gmail.com> [2017-12-15T17:31:30-0800]:  
> >> This sounds like a reasonable thing to add.  See builtin/mv.c for
> >> how "git mv" works if you're looking for inspiration.
> >> 
> >> cmd_mv in that file looks rather long, so I'd also be happy if
> >> someone interested refactors to break it into multiple
> >> self-contained pieces for easier reading (git mostly follows
> >> https://www.kernel.org/doc/html/latest/process/coding-style.html#functions).
> >>   
> >
> > I looked at builtin/mv.c and have a rough idea how to split it
> > up to support both mv and cp commands.
> >
> > But first I noticed and removed a redundant check in cmd_mv,
> > also added a test case to check if mv --dry-run does not move
> > the file.  
> 
> I guess these two patches went unnoticed when posted at the end of
> last year.  Reading them again, I think they are good changes.

Thanks.

Are such redundant checks in general a pattern worth searching
for and cleaning up globally? Or is this rather in the category
of cleaning up only when noticed?


> As a no-op clean-up of a127331c ("mv: allow moving nested
> submodules", 2016-04-19), the attached would also make sense, I
> would think.
> 
> Thanks.
> 
>  builtin/mv.c | 7 ---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/builtin/mv.c b/builtin/mv.c
> index 9662804d23..9cb07990fd 100644
> --- a/builtin/mv.c
> +++ b/builtin/mv.c
> @@ -266,10 +266,11 @@ int cmd_mv(int argc, const char **argv, const
> char *prefix) const char *src = source[i], *dst = destination[i];
>   enum update_mode mode = modes[i];
>   int pos;
> - if (show_only || verbose)
> - printf(_("Renaming %s to %s\n"), src, dst);
> - if (show_only)
> + if (show_only) {
> + if (verbose)
> + printf(_("Renaming %s to %s\n"),
> src, dst); continue;
> + }
>   if (mode != INDEX && rename(src, dst) < 0) {
>   if (ignore_errors)
>   continue;
> 

As Stefan Beller already noted, this changes the printing
behavior:
<https://public-inbox.org/git/CAGZ79kbX4uhDpdp0kH=8+5tj_zlwzbtbmub5wwtoexwrqz8...@mail.gmail.com/>

See also the output of

git mv -n
git mv -n -v
git mv -v


without your patch:

$ git mv -n 1 2
Checking rename of '1' to '2'
Renaming 1 to 2
$ git mv -n -v 1 2
Checking rename of '1' to '2'
Renaming 1 to 2
$ git mv -v 1 2
Renaming 1 to 2


and with your patch:

$ git mv -n 1 2
Checking rename of '1' to '2'
$ git mv -n -v 1 2
Checking rename of '1' to '2'
Renaming 1 to 2
$ git mv -v 1 2


Having different outputs of “git mv -n” and “git mv -n -v” seems
odd, but not necessarily wrong. However, “git mv -v” with no
output at all, does not what the documentation says:

   -v, --verbose
   Report the names of files as they are moved.

[PATCH 2/2] mv: remove unneeded 'if (!show_only)'

[Stefan Moch]

Commit a127331cd (mv: allow moving nested submodules,
2016-04-19), introduced

if (show_only) continue;

in this for-loop before

if (!show_only)

which became redundant, because it is now always true.

Signed-off-by: Stefan Moch <stefanm...@mail.de>
---
 builtin/mv.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/builtin/mv.c b/builtin/mv.c
index cf3684d90..8ce6a2ddd 100644
--- a/builtin/mv.c
+++ b/builtin/mv.c
@@ -286,8 +286,7 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 
pos = cache_name_pos(src, strlen(src));
assert(pos >= 0);
-   if (!show_only)
-   rename_cache_entry_at(pos, dst);
+   rename_cache_entry_at(pos, dst);
}
 
if (gitmodules_modified)
-- 
2.14.3

[PATCH 1/2] Add test case for mv --dry-run to t7001-mv.sh

[Stefan Moch]

It checks if mv --dry-run does not move file.

Signed-off-by: Stefan Moch <stefanm...@mail.de>
---
 t/t7001-mv.sh | 6 ++
 1 file changed, 6 insertions(+)

diff --git a/t/t7001-mv.sh b/t/t7001-mv.sh
index 6e5031f56..d4e6485a2 100755
--- a/t/t7001-mv.sh
+++ b/t/t7001-mv.sh
@@ -38,6 +38,12 @@ test_expect_success \
 'git diff-tree -r -M --name-status  HEAD^ HEAD | \
 grep "^R100..*path1/COPYING..*path0/COPYING"'
 
+test_expect_success \
+'mv --dry-run does not move file' \
+'git mv -n path0/COPYING MOVED &&
+ test -f path0/COPYING &&
+ test ! -f MOVED'
+
 test_expect_success \
 'checking -k on non-existing file' \
 'git mv -k idontexist path0'
-- 
2.14.3

Re: feature-request: git "cp" like there is git mv.

[Stefan Moch]

* Jonathan Nieder  [2017-12-15T17:31:30-0800]:
> This sounds like a reasonable thing to add.  See builtin/mv.c for how
> "git mv" works if you're looking for inspiration.
> 
> cmd_mv in that file looks rather long, so I'd also be happy if someone
> interested refactors to break it into multiple self-contained pieces
> for easier reading (git mostly follows
> https://www.kernel.org/doc/html/latest/process/coding-style.html#functions).

I looked at builtin/mv.c and have a rough idea how to split it
up to support both mv and cp commands.

But first I noticed and removed a redundant check in cmd_mv,
also added a test case to check if mv --dry-run does not move
the file.


Stefan