Re: [PATCH] branch: issue "-l" deprecation warning after pager starts

On Fri, May 25, 2018 at 10:55:45AM +0900, Junio C Hamano wrote:

Jeff King [off-list ref] writes:

quoted

Hmm, actually, I suppose the true value of the warning is to help people
doing "git branch -l foo", and it would still work there. The "more
extreme" from your suggested patch would only affect "branch -l".

quoted

Still, I think I prefer the gentler version that we get by keeping it as
a warning even in the latter case.

"git branch -l newbranch [forkpoint]" that warns "We won't be doing
reflog creation with -l" is good, but "git branch -l" that warns "We
won't be doing reflog creation with -l" sounds like a pure noise, as
the user would say "Irrelevant, I am not doing that anyway--I am
listing".

The warning to prepare users for the next step jk/branch-l-1-removal
should say "we won't be accepting '-l' as a silent and unadvertised
synonym soon. Spell it as --list" when "git branch -l" is given, I
would think.

I hoped that reminding them that "-l is a synonym for --create-reflog"
would serve as a gentle reminder that they're Doing It Wrong. I guess we
could be more explicit, though.

It is not "we won't be accepting -l as a synonym" though. It was never a
synonym, it's just that it didn't happen to do anything in list mode.

quoted

@@ -700,6 +700,11 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 	if (list)
 		setup_auto_pager("branch", 1);
 
+	if (used_deprecated_reflog_option) {
+		warning("the '-l' alias for '--create-reflog' is deprecated;");
+		warning("it will be removed in a future version of Git");
+	}

So from that point of view, we may need a separate message to warn
users who _do_ want listing with '-l' before jk/branch-l-1-removal
removes it?  

The jk/branch-l-2-resurrection topic later repurposes '-l' for
'--list' but until that happens 'git branch -l' will error not, no?

Yes, after step 1 it will error out. Again, I hoped the existing message
would prepare people. But maybe we should do this on top of what I
posted earlier?

-- >8 --
Subject: [PATCH] branch: customize "-l" warning in list mode

People mistakenly use "git branch -l", thinking that it
triggers list mode. It doesn't, but the lack of non-option
arguments in that command does (and the "-l" becomes a
silent noop).

Since afc968e579 (branch: deprecate "-l" option, 2018-03-26)
we've warned that "-l" is going away. But the warning text
is primarily aimed at people who _meant_ to use "-l", as in
"git branch -l foo". People who mistakenly said "git branch
-l" may be left puzzled.

Let's make it clear that:

  1. No, "-l" didn't do what they thought here.

  2. It's going away, and what they should do instead.

Signed-off-by: Jeff King <redacted>
---
 builtin/branch.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/builtin/branch.c b/builtin/branch.c
index 55bfacd843..b0b33dab94 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c

@@ -701,8 +701,14 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		setup_auto_pager("branch", 1);
 
 	if (used_deprecated_reflog_option) {
-		warning("the '-l' alias for '--create-reflog' is deprecated;");
-		warning("it will be removed in a future version of Git");
+		if (list) {
+			warning("the '-l' option is an alias for '--create-reflog' and");
+			warning("has no effect in list mode. This option will soon be");
+			warning("removed and you should omit it (or use '--list' instead).");
+		} else {
+			warning("the '-l' alias for '--create-reflog' is deprecated;");
+			warning("it will be removed in a future version of Git");
+		}
 	}
 
 	if (delete) {

-- 
2.17.0.1391.g6fdbf40724