[PATCH] read-tree.txt: clarify --reset and worktree changes

[PATCH] read-tree.txt: clarify --reset and worktree changes

[Nguyễn Thái Ngọc Duy]

The description of --reset stays true to the first implementation in
438195cced (git-read-tree: add "--reset" flag, 2005-06-09). That is,
--reset discards unmerged entries. Or at least true to the commit
message because I can't be sure about read-tree's behavior regarding
local changes.

But in fcc387db9b (read-tree -m -u: do not overwrite or remove untracked
working tree files., 2006-05-17), it is clear that "-m -u" tries to keep
local changes, while --reset is singled out and will keep overwriting
worktree files. It's not stated in the commit message, but it's obvious
from the patch.

I went this far back not because I had a lot of free time, but because I
did not trust my reading of unpack-trees.c code. So far I think the
related changes in history agree with my understanding of the current
code, that "--reset" loses local changes.

This behavior is not mentioned in git-read-tree.txt, even though
old-timers probably can just guess it based on the "reset" name. Update
git-read-tree.txt about this.

Side note. There's another change regarding --reset that is not
obviously about local changes, b018ff6085 (unpack-trees: fix "read-tree
-u --reset A B" with conflicted index, 2012-12-29). But I'm pretty sure
this is about the first function of --reset, to discard unmerged entries
correctly.

PS. The patch changes one more line than necessary because the first
line uses spaces instead of tab.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 Documentation/git-read-tree.txt | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
index 5c70bc2878..12a25bc954 100644
--- a/Documentation/git-read-tree.txt
+++ b/Documentation/git-read-tree.txt
@@ -38,8 +38,9 @@ OPTIONS
 	started.
 
 --reset::
-        Same as -m, except that unmerged entries are discarded
-        instead of failing.
+	Same as -m, except that unmerged entries are discarded
+	instead of failing. If `-u` is used, updates leading to loss
+	of local changes will not abort the operation.
 
 -u::
 	After a successful merge, update the files in the work
-- 
2.21.0.479.g47ac719cd3

Re: [PATCH] read-tree.txt: clarify --reset and worktree changes

[Junio C Hamano]

Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:

> diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
> index 5c70bc2878..12a25bc954 100644
> --- a/Documentation/git-read-tree.txt
> +++ b/Documentation/git-read-tree.txt
> @@ -38,8 +38,9 @@ OPTIONS
>  	started.
>  
>  --reset::
> -        Same as -m, except that unmerged entries are discarded
> -        instead of failing.
> +	Same as -m, except that unmerged entries are discarded
> +	instead of failing. If `-u` is used, updates leading to loss
> +	of local changes will not abort the operation.

"git add $file" makes a local change to the index at path $file",
and reverting that local change is what "read-tree --reset"
primarily does.

The difference cased by presence or lack of "-u" is only about the
working tree files, so s/local/working tree/ perhaps?

I'd also phrase s/If `-u` is used/When used with `-u`/ if I were
writing this.

Thanks.

>  
>  -u::
>  	After a successful merge, update the files in the work

Re: [PATCH] read-tree.txt: clarify --reset and worktree changes

[Duy Nguyen]

On Mon, Apr 1, 2019 at 5:47 PM Junio C Hamano <gitster@pobox.com> wrote:
>
> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>
> > diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
> > index 5c70bc2878..12a25bc954 100644
> > --- a/Documentation/git-read-tree.txt
> > +++ b/Documentation/git-read-tree.txt
> > @@ -38,8 +38,9 @@ OPTIONS
> >       started.
> >
> >  --reset::
> > -        Same as -m, except that unmerged entries are discarded
> > -        instead of failing.
> > +     Same as -m, except that unmerged entries are discarded
> > +     instead of failing. If `-u` is used, updates leading to loss
> > +     of local changes will not abort the operation.
>
> "git add $file" makes a local change to the index at path $file",
> and reverting that local change is what "read-tree --reset"
> primarily does.

That sounds more like "reset $file" than "read-tree --reset" actually,
which works on a full tree instead of a path.

> The difference cased by presence or lack of "-u" is only about the
> working tree files, so s/local/working tree/ perhaps?
>
> I'd also phrase s/If `-u` is used/When used with `-u`/ if I were
> writing this.

Updated. v2 coming.

>
> Thanks.
>
> >
> >  -u::
> >       After a successful merge, update the files in the work



-- 
Duy

[PATCH v2] read-tree.txt: clarify --reset and worktree changes

[Nguyễn Thái Ngọc Duy]

The description of --reset stays true to the first implementation in
438195cced (git-read-tree: add "--reset" flag, 2005-06-09). That is,
--reset discards unmerged entries. Or at least true to the commit
message because I can't be sure about read-tree's behavior regarding
local changes.

But in fcc387db9b (read-tree -m -u: do not overwrite or remove untracked
working tree files., 2006-05-17), it is clear that "-m -u" tries to keep
local changes, while --reset is singled out and will keep overwriting
worktree files. It's not stated in the commit message, but it's obvious
from the patch.

I went this far back not because I had a lot of free time, but because I
did not trust my reading of unpack-trees.c code. So far I think the
related changes in history agree with my understanding of the current
code, that "--reset" loses local changes.

This behavior is not mentioned in git-read-tree.txt, even though
old-timers probably can just guess it based on the "reset" name. Update
git-read-tree.txt about this.

Side note. There's another change regarding --reset that is not
obviously about local changes, b018ff6085 (unpack-trees: fix "read-tree
-u --reset A B" with conflicted index, 2012-12-29). But I'm pretty sure
this is about the first function of --reset, to discard unmerged entries
correctly.

PS. The patch changes one more line than necessary because the first
line uses spaces instead of tab.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 v2 updates a bit to emphasize on worktree changes.

 Documentation/git-read-tree.txt | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
index 5c70bc2878..7061d6634e 100644
--- a/Documentation/git-read-tree.txt
+++ b/Documentation/git-read-tree.txt
@@ -38,8 +38,9 @@ OPTIONS
 	started.
 
 --reset::
-        Same as -m, except that unmerged entries are discarded
-        instead of failing.
+	Same as -m, except that unmerged entries are discarded instead
+	of failing. When used with `-u`, updates leading to loss of
+	working tree changes will not abort the operation.
 
 -u::
 	After a successful merge, update the files in the work
-- 
2.21.0.479.g47ac719cd3