[PATCH] Hint at "checkout -p" in the "reset --patch <type>" error message

The --patch option to git-reset is not compatible with the type
specifiers (--hard et al.), but some users try that first when what they
really want is "checkout -p" (cf.
<http://permalink.gmane.org/gmane.comp.version-control.git/161955>).

Mention "git checkout -p" in the error message to point users in the
right direction.

Signed-off-by: Štěpán Němec <redacted>
---

Jeenu V [off-list ref] writes:

On Tue, Nov 23, 2010 at 4:28 PM, knittl [off-list ref] wrote:

quoted

`git reset` seldomly affects the working tree, unless using `--hard`,
`--merge` or `--keep`, and those switches are potentially dangerous if
you are not aware of the implications to your worktree and index.

without options reset undoes a previous add, i.e. remove changes from
the index, but not the working tree.

git reset manpage mentions git-checkout:

Agreed. What I'm saying is most manuals/guides out there tips user to
use 'git reset --hard' to discard changes in the working directory and
restore the pristine copy of files. 'reset' then becomes synonymous to
discard, and it kind of is but for a different reason. Because other
commands offer -p for selective operations, one might try to discard
selectively, and end up using 'git reset -p --hard', which obviously
isn't going to work.

Knowing the users intention in such cases, I was suggesting the error
message could hint the right command (just like git commit hints user
to use git-add when one does 'git commit' with a dirty working tree).

But that's just me.

Well, maybe something like the patch below wouldn't hurt?

 builtin/reset.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/builtin/reset.c b/builtin/reset.c
index 0037be4..fc530d2 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c

@@ -309,7 +309,8 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 
 	if (patch_mode) {
 		if (reset_type != NONE)
-			die("--patch is incompatible with --{hard,mixed,soft}");
+			die("--patch is incompatible with --{hard,mixed,soft}\n"
+			    "(use \"git checkout -p\" to selectively discard changes in working directory)");
 		return interactive_reset(rev, argv + i, prefix);
 	}
 

-- 
1.7.3.rc2.221.gbf93f.dirty

On Tue, Nov 23, 2010 at 03:20:58PM +0100, Štěpán Němec wrote:

Should this actually print something different for --hard versus --mixed
versus --soft?

For --soft, "-p" simply makes no sense as you are not changing the index
or the working directory.

For --mixed, shouldn't we support "-p" already, as that is the default
mode?

For --hard, suggesting "checkout -p" does make sense.

Also, what about "--merge" and "--keep" modes?

-Peff