* jl/nor-or-nand-and:
code and test: fix misuses of "nor"
comments: fix misuses of "nor"
contrib: fix misuses of "nor"
Documentation: fix misuses of "nor"
* cn/fetch-prune-overlapping-destination:
fetch: handle overlaping refspecs on --prune
fetch: add a failing test for prunning with overlapping refspecs
We need to consider that a remote-tracking branch may match more than
one rhs of a fetch refspec. In such a case, it is not enough to stop at
the first match but look at all of the matches in order to determine
whether a head is stale.
To this goal, introduce a variant of query_refspecs which returns all of
the matching refspecs and loop over those answers to check for
staleness.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git push" did not pay attention to branch.*.pushremote if it is
defined earlier than remote.pushdefault; the order of these two
variables in the configuration file should not matter, but it did by
mistake.
* jk/remote-pushremote-config-reading:
remote: handle pushremote config in any order
The remote we push can be defined either by
remote.pushdefault or by branch.*.pushremote for the current
branch. The order in which they appear in the config file
should not matter to precedence (which should be to prefer
the branch-specific config).
The current code parses the config linearly and uses a
single string to store both values, overwriting any
previous value. Thus, config like:
[branch "master"]
pushremote = foo
[remote]
pushdefault = bar
erroneously ends up pushing to "bar" from the master branch.
We can fix this by storing both values and resolving the
correct value after all config is read.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We used to use two separate rules for the normal ref resolution
dwimming and dwimming done to decide which remote ref to grab. The
third parameter to refname_match() selected which rules to use.
When these two rules were harmonized in
2011-11-04 dd621df9cd refs DWIMmery: use the same rule for both "git fetch" and others
, ref_fetch_rules was #defined to avoid potential breakages for
in-flight topics.
It is now safe to remove the backwards-compatibility code, so remove
refname_match()'s third parameter, make ref_rev_parse_rules private to
refs.c, and remove ref_fetch_rules entirely.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make "git push origin master" update the same ref that would be
updated by our 'master' when "git push origin" (no refspecs) is run
while the 'master' branch is checked out, which makes "git push"
more symmetric to "git fetch" and more usable for the triangular
workflow.
* jc/push-refmap:
push: also use "upstream" mapping when pushing a single ref
push: use remote.$name.push as a refmap
builtin/push.c: use strbuf instead of manual allocation
Remove a few duplicate implementations of prefix/suffix comparison
functions, and rename them to starts_with and ends_with.
* cc/starts-n-ends-with:
replace {pre,suf}fixcmp() with {starts,ends}_with()
strbuf: introduce starts_with() and ends_with()
builtin/remote: remove postfixcmp() and use suffixcmp() instead
environment: normalize use of prefixcmp() by removing " != 0"
The "--tags" option to "git fetch" used to be literally a synonym to
a "refs/tags/*:refs/tags/*" refspec, which meant that (1) as an
explicit refspec given from the command line, it silenced the lazy
"git fetch" default that is configured, and (2) also as an explicit
refspec given from the command line, it interacted with "--prune"
to remove any tag that the remote we are fetching from does not
have.
This demotes it to an option; with it, we fetch all tags in
addition to what would be fetched without the option, and it does
not interact with the decision "--prune" makes to see what
remote-tracking refs the local has are missing the remote
counterpart.
* mh/fetch-tags-in-addition-to-normal-refs: (23 commits)
fetch: improve the error messages emitted for conflicting refspecs
handle_duplicate(): mark error message for translation
ref_remote_duplicates(): extract a function handle_duplicate()
ref_remove_duplicates(): simplify loop logic
t5536: new test of refspec conflicts when fetching
ref_remove_duplicates(): avoid redundant bisection
git-fetch.txt: improve description of tag auto-following
fetch-options.txt: simplify ifdef/ifndef/endif usage
fetch, remote: properly convey --no-prune options to subprocesses
builtin/remote.c:update(): use struct argv_array
builtin/remote.c: reorder function definitions
query_refspecs(): move some constants out of the loop
fetch --prune: prune only based on explicit refspecs
fetch --tags: fetch tags *in addition to* other stuff
fetch: only opportunistically update references based on command line
get_expanded_map(): avoid memory leak
get_expanded_map(): add docstring
builtin/fetch.c: reorder function definitions
get_ref_map(): rename local variables
api-remote.txt: correct section "struct refspec"
...
Leaving only the function definitions and declarations so that any
new topic in flight can still make use of the old functions, replace
existing uses of the prefixcmp() and suffixcmp() with new API
functions.
The change can be recreated by mechanically applying this:
$ git grep -l -e prefixcmp -e suffixcmp -- \*.c |
grep -v strbuf\\.c |
xargs perl -pi -e '
s|!prefixcmp\(|starts_with\(|g;
s|prefixcmp\(|!starts_with\(|g;
s|!suffixcmp\(|ends_with\(|g;
s|suffixcmp\(|!ends_with\(|g;
'
on the result of preparatory changes in this series.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since f2690487 (fetch: opportunistically update tracking refs,
2013-05-11), we stopped taking a non-storing refspec given on the
command line of "git fetch" literally, and instead started mapping
it via remote.$name.fetch refspecs. This allows
$ git fetch origin master
from the 'origin' repository, which is configured with
[remote "origin"]
fetch = +refs/heads/*:refs/remotes/origin/*
to update refs/remotes/origin/master with the result, as if the
command line were
$ git fetch origin +master:refs/remotes/origin/master
to reduce surprises and improve usability. Before that change, a
refspec on the command line without a colon was only to fetch the
history and leave the result in FETCH_HEAD, without updating the
remote-tracking branches.
When you are simulating a fetch from you by your mothership with a
push by you into your mothership, instead of having:
[remote "satellite"]
fetch = +refs/heads/*:refs/remotes/satellite/*
on the mothership repository and running:
mothership$ git fetch satellite
you would have:
[remote "mothership"]
push = +refs/heads/*:refs/remotes/satellite/*
on your satellite machine, and run:
satellite$ git push mothership
Because we so far did not make the corresponding change to the push
side, this command:
satellite$ git push mothership master
does _not_ allow you on the satellite to only push 'master' out but
still to the usual destination (i.e. refs/remotes/satellite/master).
Implement the logic to map an unqualified refspec given on the
command line via the remote.$name.push refspec. This will bring a
bit more symmetry between "fetch" and "push".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we find two refspecs that want to update the same local reference,
emit an error message that is more informative based on whether one of
the conflicting refspecs is an opportunistic update during a fetch
with explicit command-line refspecs. And especially, do not die if an
opportunistic reference update conflicts with an express wish of the
user; rather, just emit a warning and skip the opportunistic reference
update.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the loop body into the more straightforward
* remove item from the front of the old list
* if necessary, add it to the tail of the new list
and return a pointer to the new list (even though it is currently
always the same as the input argument, because the first element in
the list is currently never deleted).
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The old code called string_list_lookup(), and if that failed called
string_list_insert(), thus doing the bisection search through the
string list twice in the latter code path.
Instead, just call string_list_insert() right away. If an entry for
that peer reference name already existed, then its util pointer is
always non-NULL.
Of course this doesn't change the fact that the repeated
string_list_insert() calls make the function scale like O(N^2) if the
input reference list is not already approximately sorted.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The old code could leak *expn_name if match_name_with_pattern()
succeeded but ignore_symref_update() returned true. So make sure that
*expn_name is freed in any case.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our default_remote_name starts at "origin", but may be
overridden by the config file. In the former case, we
allocate a new string, but in the latter case, we point to
the remote name in an existing "struct branch".
This gives the variable inconsistent free() semantics (we
are sometimes responsible for freeing the string and
sometimes pointing to somebody else's storage), and causes a
small leak when the allocated string is overridden by
config.
We can fix both by simply dropping the extra copy and
pointing to the string literal.
Noticed-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git branch -v -v" (and "git status") did not distinguish among a
branch that does not build on any other branch, a branch that is in
sync with the branch it builds on, and a branch that is configured
to build on some other branch that no longer exists.
* jx/branch-vv-always-compare-with-upstream:
status: always show tracking branch even no change
branch: report invalid tracking branch as gone
Allow a safer "rewind of the remote tip" push than blind "--force",
by requiring that the overwritten remote ref to be unchanged since
the new history to replace it was prepared.
The machinery is more or less ready. The "--force" option is again
the big red button to override any safety, thanks to J6t's sanity
(the original round allowed --lockref to defeat --force).
The logic to choose the default implemented here is fragile
(e.g. "git fetch" after seeing a failure will update the
remote-tracking branch and will make the next "push" pass,
defeating the safety pretty easily). It is suitable only for the
simplest workflows, and it may hurt users more than it helps them.
* jc/push-cas:
push: teach --force-with-lease to smart-http transport
send-pack: fix parsing of --force-with-lease option
t5540/5541: smart-http does not support "--force-with-lease"
t5533: test "push --force-with-lease"
push --force-with-lease: tie it all together
push --force-with-lease: implement logic to populate old_sha1_expect[]
remote.c: add command line option parser for "--force-with-lease"
builtin/push.c: use OPT_BOOL, not OPT_BOOLEAN
cache.h: move remote/connect API out of it
Allow fetch.prune and remote.*.prune configuration variables to be set,
and "git fetch" to behave as if "--prune" is given.
"git fetch" that honors remote.*.prune is fine, but I wonder if we
should somehow make "git push" aware of it as well. Perhaps
remote.*.prune should not be just a boolean, but a 4-way "none",
"push", "fetch", "both"?
* ms/fetch-prune-configuration:
fetch: make --prune configurable
In order to see what the current branch is tracking, one way is using
"git branch -v -v", but branches other than the current are also
reported. Another way is using "git status", such as:
$ git status
# On branch master
# Your branch is ahead of 'origin/master' by 1 commit.
...
But this will not work if there is no change between the current
branch and its upstream. Always report upstream tracking info
even if there is no difference, so that "git status" is consistent
for checking tracking info for current branch. E.g.
$ git status
# On branch feature1
# Your branch is up-to-date with 'github/feature1'.
...
$ git status -bs
## feature1...github/feature1
...
$ git checkout feature1
Already on 'feature1'
Your branch is up-to-date with 'github/feature1'.
...
Also add some test cases in t6040.
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Command "git branch -vv" will report tracking branches, but invalid
tracking branches are also reported. This is because the function
stat_tracking_info() can not distinguish invalid tracking branch
from other cases which it would not like to report, such as
there is no upstream settings at all, or nothing is changed between
one branch and its upstream.
Junio suggested missing upstream should be reported [1] like:
$ git branch -v -v
master e67ac84 initial
* topic 3fc0f2a [topicbase: gone] topic
$ git status
# On branch topic
# Your branch is based on 'topicbase', but the upstream is gone.
# (use "git branch --unset-upstream" to fixup)
...
$ git status -b -s
## topic...topicbase [gone]
...
In order to do like that, we need to distinguish these three cases
(i.e. no tracking, with configured but no longer valid tracking, and
with tracking) in function stat_tracking_info(). So the refactored
function stat_tracking_info() has three return values: -1 (with "gone"
base), 0 (no base), and 1 (with base).
If the caller does not like to report tracking info when nothing
changed between the branch and its upstream, simply checks if
num_theirs and num_ours are both 0.
[1]: http://thread.gmane.org/gmane.comp.version-control.git/231830/focus=232288
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This teaches the deepest part of the callchain for "git push" (and
"git send-pack") to enforce "the old value of the ref must be this,
otherwise fail this push" (aka "compare-and-swap" / "--lockref").
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This plugs the push_cas_option data collected by the command line
option parser to the transport system with a new function
apply_push_cas(), which is called after match_push_refs() has
already been called.
At this point, we know which remote we are talking to, and what
remote refs we are going to update, so we can fill in the details
that may have been missing from the command line, such as
(1) what abbreviated refname the user gave us matches the actual
refname at the remote; and
(2) which remote-tracking branch in our local repository to read
the value of the object to expect at the remote.
to populate the old_sha1_expect[] field of each of the remote ref.
As stated in the documentation, the use of remote-tracking branch
as the default is a tentative one, and we may come up with a better
logic as we gain experience.
Still nobody uses this information, which is the topic of the next
patch.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update "git push" and "git send-pack" to parse this commnd line
option.
The intended sematics is:
* "--force-with-lease" alone, without specifying the details, will
protect _all_ remote refs that are going to be updated by
requiring their current value to be the same as some reasonable
default, unless otherwise specified;
* "--force-with-lease=refname", without specifying the expected
value, will protect that refname, if it is going to be updated,
by requiring its current value to be the same as some reasonable
default.
* "--force-with-lease=refname:value" will protect that refname, if
it is going to be updated, by requiring its current value to be
the same as the specified value; and
* "--no-force-with-lease" will cancel all the previous --force-with-lease on the
command line.
For now, "some reasonable default" is tentatively defined as "the
value of the remote-tracking branch we have for the ref of the
remote being updated", and it is an error if we do not have such a
remote-tracking branch. But this is known to be fragile, its use is
not yet recommended, and hopefully we will find more reasonable
default as we gain experience with this feature. The manual marks
the feature as experimental unless the expected value is specified
explicitly for this reason.
Because the command line options are parsed _before_ we know which
remote we are pushing to, there needs further processing to the
parsed data after we instantiate the transport object to:
* expand "refname" given by the user to a full refname to be
matched with the list of "struct ref" used in match_push_refs()
and set_ref_status_for_push(); and
* learning the actual local ref that is the remote-tracking branch
for the specified remote ref.
Further, some processing need to be deferred until we find the set
of remote refs and match_push_refs() returns in order to find the
ones that need to be checked after explicit ones have been processed
for "--force-with-lease" (no specific details).
These post-processing will be the topic of the next patch.
This option was originally called "cas" (for "compare and swap"),
the name which nobody liked because it was too technical. The
second attempt called it "lockref" (because it is conceptually like
pushing after taking a lock) but the word "lock" was hated because
it implied that it may reject push by others, which is not the way
this option works. This round calls it "force-with-lease". You
assume you took the lease on the ref when you fetched to decide what
the rebased history should be, and you can push back only if the
lease has not been broken.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Without "git fetch --prune", remote-tracking branches for a branch
the other side already has removed will stay forever. Some people
want to always run "git fetch --prune".
To accommodate users who want to either prune always or when fetching
from a particular remote, add two new configuration variables
"fetch.prune" and "remote.<name>.prune":
- "fetch.prune" allows to enable prune for all fetch operations.
- "remote.<name>.prune" allows to change the behaviour per remote.
The latter will naturally override the former, and the --[no-]prune
option from the command line will override the configured default.
Since --prune is a potentially destructive operation (Git doesn't
keep reflogs for deleted references yet), we don't want to prune
without users consent, so this configuration will not be on by
default.
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Schubert <mschub@elegosoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Pushing to repositories with many refs employed O(m*n) algorithm
where n is the number of refs on the receiving end.
* bc/push-match-many-refs:
remote.c: avoid O(m*n) behavior in match_push_refs
The definition of "struct ref" in "cache.h", a header file so
central to the system, always confused me. This structure is not
about the local ref used by sha1-name API to name local objects.
It is what refspecs are expanded into, after finding out what refs
the other side has, to define what refs are updated after object
transfer succeeds to what values. It belongs to "remote.h" together
with "struct refspec".
While we are at it, also move the types and functions related to the
Git transport connection to a new header file connect.h
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When pushing using a matching refspec or a pattern refspec, each ref
in the local repository must be paired with a ref advertised by the
remote server. This is accomplished by using the refspec to transform
the name of the local ref into the name it should have in the remote
repository, and then performing a linear search through the list of
remote refs to see if the remote ref was advertised by the remote
system.
Each of these lookups has O(n) complexity and makes match_push_refs()
be an O(m*n) operation, where m is the number of local refs and n is
the number of remote refs. If there are many refs 100,000+, then this
ref matching can take a significant amount of time. Let's prepare an
index of the remote refs to allow searching in O(log n) time and
reduce the complexity of match_push_refs() to O(m log n).
We prepare the index lazily so that it is only created when necessary.
So, there should be no impact when _not_ using a matching or pattern
refspec, i.e. when pushing using only explicit refspecs.
Dry-run push of a repository with 121,913 local and remote refs:
before after
real 1m40.582s 0m0.804s
user 1m39.914s 0m0.515s
sys 0m0.125s 0m0.106s
The creation of the index has overhead. So, if there are very few
local refs, then it could take longer to create the index than it
would have taken to just perform n linear lookups into the remote
ref space. Using the index should provide some improvement when
the number of local refs is roughly greater than the log of the
number of remote refs (i.e. m >= log n). The pathological case is
when there is a single local ref and very many remote refs.
Dry-run push of a repository with 121,913 remote refs and a single
local ref:
before after
real 0m0.525s 0m0.566s
user 0m0.243s 0m0.279s
sys 0m0.075s 0m0.099s
Using an index takes 41 ms longer, or roughly 7.8% longer.
Jeff King measured a no-op push of a single ref into a remote repo
with 370,000 refs:
before after
real 0m1.087s 0m1.156s
user 0m1.344s 0m1.412s
sys 0m0.288s 0m0.284s
Using an index takes 69 ms longer, or roughly 6.3% longer.
None of the measurements above required transferring any objects to
the remote repository. If the push required transferring objects and
updating the refs in the remote repository, the impact of preparing
the search index would be even smaller.
A similar operation is performed in the reverse direction when pruning
using a matching or pattern refspec. Let's avoid O(m*n) behavior in
the same way by lazily preparing an index on the local refs.
Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The first line of the function checks that the remote-name contains a
slash ('/'), and sets the "slash" variable accordingly. The only caller
of read_branches_file() is remote_get_1(); the calling codepath is
guarded by valid_remote_nick(), which checks that the remote does not
contain a slash. Therefore, the "slash" variable can never be set:
remove the dead code that assumes otherwise.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This new configuration variable overrides `remote.pushdefault` and
`branch.<name>.remote` for pushes. When you pull from one
place (e.g. your upstream) and push to another place (e.g. your own
publishing repository), you would want to set `remote.pushdefault` to
specify the remote to push to for all branches, and use this option to
override it for a specific branch.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This new configuration variable defines the default remote to push to,
and overrides `branch.<name>.remote` for all branches. It is useful
in the typical triangular-workflow setup, where the remote you're
fetching from is different from the remote you're pushing to.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, do_push() in push.c calls remote_get(), which gets the
configured remote for fetching and pushing. Replace this call with a
call to pushremote_get() instead, a new function that will return the
remote configured specifically for pushing. This function tries to
work with the string pushremote_name, before falling back to the
codepath of remote_get(). This patch has no visible impact, but
serves to enable future patches to introduce configuration variables
to set pushremote_name. For example, you can now do the following in
handle_config():
if (!strcmp(key, "remote.pushdefault"))
git_config_string(&pushremote_name, key, value);
Then, pushes will automatically go to the remote specified by
remote.pushdefault.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A small segment where handle_config() parses the branch.remote
configuration variable can be simplified using git_config_string().
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allows requests to fetch objects at any tip of refs (including
hidden ones). It seems that there may be use cases even outside
Gerrit (e.g. $gmane/215701).
* jc/fetch-raw-sha1:
fetch: fetch objects by their exact SHA-1 object names
upload-pack: optionally allow fetching from the tips of hidden refs
fetch: use struct ref to represent refs to be fetched
parse_fetch_refspec(): clarify the codeflow a bit
The new option "--follow-tags" tells "git push" to push annotated
tags that are missing from the other side and that can be reached by
the history that is otherwise pushed out.
For example, if you are using the "simple", "current", or "upstream"
push, you would ordinarily push the history leading to the commit at
your current HEAD and nothing else. With this option, you would
also push all annotated tags that can be reached from that commit to
the other side.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In ancient times, we used to disallow the same source ref to be
pushed to more than one places, e.g. "git push there master:master
master:naster" was disallowed. We later lifted this restriction
with db27ee6392 (send-pack: allow the same source to be pushed
more than once., 2005-08-06) and there no longer is anybody that
sets peer_ref for the source side of the ref list in the push
codepath since then.
Remove one leftover no-op in a loop that iterates over the source
side of ref list (i.e. our local ref) to see if it can/should be
sent to a matching destination ref while skipping ones that is
marked with peer_ref (which will never exist, so we do not skip
anything).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach "git fetch" to accept an exact SHA-1 object name the user may
obtain out of band on the LHS of a pathspec, and send it on a "want"
message when the server side advertises the allow-tip-sha1-in-want
capability.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most parts of the cascaded if/else if/... checked an allowable
condition but some checked forbidden conditions. This makes adding
new allowable conditions unnecessarily inconvenient.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Improve error and advice messages given locally when "git push"
refuses when it cannot compute fast-forwardness by separating these
cases from the normal "not a fast-forward; merge first and push
again" case.
* jc/push-reject-reasons:
push: finishing touches to explain REJECT_ALREADY_EXISTS better
push: introduce REJECT_FETCH_FIRST and REJECT_NEEDS_FORCE
push: further simplify the logic to assign rejection reason
push: further clean up fields of "struct ref"
When we push to update an existing ref, if:
* the object at the tip of the remote is not a commit; or
* the object we are pushing is not a commit,
it won't be correct to suggest to fetch, integrate and push again,
as the old and new objects will not "merge". We should explain that
the push must be forced when there is a non-committish object is
involved in such a case.
If we do not have the current object at the tip of the remote, we do
not even know that object, when fetched, is something that can be
merged. In such a case, suggesting to pull first just like
non-fast-forward case may not be technically correct, but in
practice, most such failures are seen when you try to push your work
to a branch without knowing that somebody else already pushed to
update the same branch since you forked, so "pull first" would work
as a suggestion most of the time. And if the object at the tip is
not a commit, "pull first" will fail, without making any permanent
damage. As a side effect, it also makes the error message the user
will get during the next "push" attempt easier to understand, now
the user is aware that a non-commit object is involved.
In these cases, the current code already rejects such a push on the
client end, but we used the same error and advice messages as the
ones used when rejecting a non-fast-forward push, i.e. pull from
there and integrate before pushing again.
Introduce new rejection reasons and reword the messages
appropriately.
[jc: with help by Peff on message details]
Signed-off-by: Junio C Hamano <gitster@pobox.com>