[BUG] git show <remote>: bad information: Local branch|ref configured

[BUG] git show <remote>: bad information: Local branch|ref configured

[Seth Robertson]

Over in #git we ran into a user wondering why a particular remote said
something about "master pushes to master" when the local branch mapped
to that remote was not named master.

Not having inspected the code, it certainly appears as if the "Local
branch configured" and "Local ref configured" information is only
accidentally correct, but since the normal configuration is the case
in which it is accurate, no-one noticed the problem.

In the test case below, in the "bar" case we are missing the "Local
ref configured for 'git push'" section entirely.  Strange since git push
does indeed work.

In the "baz" case we see the message and master does push to master.

In the "biff" case we see the confluence of the two previous cases.
The "foo" remote/subcase shows what we might expect, but the "baz"
remote/subcase shows the 'Local ref configured' information is a lie.
Finally, the "bar" remote/subcase shows that even the "Local branch
configured" information is somehow magic based on the remote branch
being named master.

This test was done using git 1.7.3.1

Test case prep
----------------------------------------------------------------------
mkdir foo; cd foo; git init; echo A>A; git add A; git commit -m A;
git checkout -b other; echo B>B; git add B; git commit -m B;
git checkout master

mkdir ../bar; cd ../bar; git init; git remote add foo ../foo;
git fetch foo; git checkout --track -b foo_master foo/other

mkdir ../baz; cd ../baz; git init; git remote add foo ../foo;
git fetch foo; git checkout --track -b master foo/master

mkdir ../biff; cd ../biff; git init; git remote add foo ../foo;
git fetch foo; git checkout --track -b master foo/master;
git remote add baz ../baz; git fetch baz;
git checkout --track -b baz_master baz/master
git remote add bar ../bar; git fetch bar;
git checkout --track -b bar_master bar/master
----------------------------------------------------------------------

cd ../bar; git remote show foo
 --------------------------------------------------
 * remote foo
   Fetch URL: ../foo
   Push  URL: ../foo
   HEAD branch: master
   Remote branches:
     master tracked
     other  tracked
   Local branch configured for 'git pull':
     foo_master merges with remote other
 --------------------------------------------------

cd ../baz; git remote show foo
 --------------------------------------------------
 * remote foo
   Fetch URL: ../foo
   Push  URL: ../foo
   HEAD branch: master
   Remote branches:
     master tracked
     other  tracked
   Local branch configured for 'git pull':
     master merges with remote master
   Local ref configured for 'git push':
     master pushes to master (up to date)
 --------------------------------------------------

cd ../biff; git remote show foo; git remote show baz; git remote show bar
 --------------------------------------------------
 * remote foo
   Fetch URL: ../foo
   Push  URL: ../foo
   HEAD branch: master
   Remote branches:
     master tracked
     other  tracked
   Local branch configured for 'git pull':
     master merges with remote master
   Local ref configured for 'git push':
     master pushes to master (up to date)
 * remote baz
   Fetch URL: ../baz
   Push  URL: ../baz
   HEAD branch: master
   Remote branch:
     master tracked
   Local branch configured for 'git pull':
     baz_master merges with remote master
   Local ref configured for 'git push':
     master pushes to master (up to date)
 * remote bar
   Fetch URL: ../bar
   Push  URL: ../bar
   HEAD branch: foo_master
   Remote branch:
     foo_master tracked
 --------------------------------------------------

					-Seth Robertson

Re: [BUG] git show <remote>: bad information: Local branch|ref configured

[Jonathan Nieder]

On Fri, Nov 12, 2010 at 07:41:39PM -0500, Seth Robertson wrote:

> Not having inspected the code, it certainly appears as if the "Local
> branch configured" and "Local ref configured" information is only
> accidentally correct, but since the normal configuration is the case
> in which it is accurate, no-one noticed the problem.

Funny. :)  But no, lots of people set up local branches as downstream
to no branch or to some distinct remote branch.  So first I guess it
might be useful to explain the "push matching" behavior.

Background: suppose the upstream repository has three branches:

	master
	next
	topic/better-frotz

Now I have an idea for a new feature, so I do

	git checkout -b topic/xyzzy origin/master

which forks a new branch set up to pull from master.

Now I go about usual work, making changes to master, next,
topic/better-frotz, and so on, and at the end I am on my private
topic/xyzzy branch.  Everything looks good, so it is time to push:

	git push origin

This is a shortcut for

	git push origin :

which pushes all local branches for which an upstream branch with the
same name exists.

"Wait!" you might ask.  "Why push all branches?"

It is partly historical.  A lot of people have public repositories
with multiple branches, and this is a behavior that has been found to
be very convenient for that.

"Why only branches for which an upstream branch exists?"

Some work might be private.  If you actually want to push everything,
use "git push --mirror".

"Why branches with the same name?  Why not to the branch each branch
pulls from?"

Each branch forked from master does not necessarily contain changes
that are suitable for inclusion in master immediately.  In general,
the upstream for each branch is often more stable rather than
equally stable to it, so automatic pushing upstream does not always
make sense.

However, if you want the push-to-where-you-pull-from behavior,
just add

	[push]
		default = tracking

to your ~/.gitconfig.

See the documentation for branch.<name>.merge in git-config(1) for
details on that.

For your test example: rather than sample output, could you describe
next to each command what you expect to happen and how that differs
from what happens instead?  This would make it easier to find the
lurking bugs.

Hope that helps,
Jonathan

Re: [BUG] git show <remote>: bad information: Local ref configured if push.default=tracking

[Seth Robertson]

In message <20101113010934.GA4017@burratino>, Jonathan Nieder writes:

    On Fri, Nov 12, 2010 at 07:41:39PM -0500, Seth Robertson wrote:

    > Not having inspected the code, it certainly appears as if the "Local
    > branch configured" and "Local ref configured" information is only
    > accidentally correct, but since the normal configuration is the case
    > in which it is accurate, no-one noticed the problem.

    However, if you want the push-to-where-you-pull-from behavior,
    just add
	    [push]
		    default = tracking
    to your ~/.gitconfig.

I already had this turned on in my ~/.gitconfig.  However, you bring
up a good point, the output as shown would be correct if the default
"matching" value was used.  Thus I guess the bug summary needs to be:

git show <remote> produces inaccurate information about "Local ref
configured" if git-config's push.default==tracking

    For your test example: rather than sample output, could you describe
    next to each command what you expect to happen and how that differs
    from what happens instead?  This would make it easier to find the
    lurking bugs.

In my example, I set up each remote identically and only varied the
name of the branch.  In all cases, you could push and pull changes
using `git pull` and `git push`, meaning that they were properly
configured tracking branches.  Thus, I argue that they should produce
information for "Local ref configured" in each case, and furthermore
that the named refs should be appropriate for the mapping in question.

I'll annotate the output below with my desired behavior.  Search for
"^**" in the output below.

In other news, the last argument of the last command of the Test case
prep should have been bar/foo_master instead of bar/master.  This
affects the "git remote show bar" subcase output, showing that the
"Local branch configured" information is correct.  The "Local ref
configured" information remains incorrect/obscure.  I updated the test
case to include the push.default=tracking configuration.

					-Seth Robertson


----------------------------------------------------------------------
mkdir foo; cd foo; git init; echo A>A; git add A; git commit -m A;
git checkout -b other; echo B>B; git add B; git commit -m B;
git checkout master; git config push.default tracking

mkdir ../bar; cd ../bar; git init; git remote add foo ../foo;
git fetch foo; git checkout --track -b foo_master foo/other
git config push.default tracking

mkdir ../baz; cd ../baz; git init; git remote add foo ../foo;
git fetch foo; git checkout --track -b master foo/master
git config push.default tracking

mkdir ../biff; cd ../biff; git init; git remote add foo ../foo;
git fetch foo; git checkout --track -b master foo/master;
git remote add baz ../baz; git fetch baz;
git checkout --track -b baz_master baz/master
git remote add bar ../bar; git fetch bar;
git checkout --track -b bar_master bar/foo_master
git config push.default tracking
----------------------------------------------------------------------

cd ../bar; git remote show foo
 --------------------------------------------------
 * remote foo
   Fetch URL: ../foo
   Push  URL: ../foo
   HEAD branch: master
   Remote branches:
     master tracked
     other  tracked
   Local branch configured for 'git pull':
     foo_master merges with remote other
 --------------------------------------------------
** DESIRED ADDITION **
 --------------------------------------------------
   Local ref configured for 'git push':
     foo_master pushes to other (up to date)
 --------------------------------------------------

cd ../baz; git remote show foo
 --------------------------------------------------
 * remote foo
   Fetch URL: ../foo
   Push  URL: ../foo
   HEAD branch: master
   Remote branches:
     master tracked
     other  tracked
   Local branch configured for 'git pull':
     master merges with remote master
   Local ref configured for 'git push':
     master pushes to master (up to date)
 --------------------------------------------------
** OUTPUT CORRECT **

cd ../biff; git remote show foo
 --------------------------------------------------
 * remote foo
   Fetch URL: ../foo
   Push  URL: ../foo
   HEAD branch: master
   Remote branches:
     master tracked
     other  tracked
   Local branch configured for 'git pull':
     master merges with remote master
   Local ref configured for 'git push':
     master pushes to master (up to date)
 --------------------------------------------------
** OUTPUT CORRECT **

cd ../biff; git remote show baz
 --------------------------------------------------
 * remote baz
   Fetch URL: ../baz
   Push  URL: ../baz
   HEAD branch: master
   Remote branch:
     master tracked
   Local branch configured for 'git pull':
     baz_master merges with remote master
   Local ref configured for 'git push':
     master pushes to master (up to date)
 --------------------------------------------------
** CORRECTED LAST TWO LINES **
 --------------------------------------------------
   Local ref configured for 'git push':
     baz_master pushes to master (up to date)
 --------------------------------------------------

cd ../biff; git remote show bar
 --------------------------------------------------
 * remote bar
   Fetch URL: ../bar
   Push  URL: ../bar
   HEAD branch: foo_master
   Remote branch:
     foo_master tracked
   Local branch configured for 'git pull':
     bar_master merges with remote foo_master
 --------------------------------------------------
** DESIRED ADDITION **
 --------------------------------------------------
   Local ref configured for 'git push':
     bar_master pushes to foo_master (up to date)
 --------------------------------------------------

Re: [BUG] git show <remote>: bad information: Local ref configured if push.default=tracking

[Jonathan Nieder]

Seth Robertson wrote:

> I already had this turned on in my ~/.gitconfig.  However, you bring
> up a good point, the output as shown would be correct if the default
> "matching" value was used.

Yep, the get_push_ref_states() function used by "git remote show"
wasn't updated when the "[push] default" configuration item was
introduced.

>     For your test example: rather than sample output, could you

Sorry to make busy work.  Your examples still would useful as a
test script for anyone who wants to fix this.

Thanks again for the report.

Regards,
Jonathan