[RFC PATCH v5 0/3] push: add support for pushing to remote groups

This RFC series adds support for `git push` to accept a remote group name (as configured via `remotes.<name>` in config) in addition to a single remote name, mirroring the behaviour that `git fetch` has supported for some time.

A user with multiple remotes configured as a group can now do:

    git push all-remotes

instead of pushing to each remote individually, in the same way that:

    git fetch all-remotes

already works.

The series is split into two patches:

  - Patch 1 moves `get_remote_group`, `add_remote_or_group`, and the
    `remote_group_data` struct out of builtin/fetch.c and into
    remote.c/remote.h, making them part of the public remote API.

  - Patch 2 extends builtin/push.c to use the newly public
    `add_remote_or_group()` to resolve the repository argument as
    either a single remote or a group, and pushes to each member of
    the group in turn.

Changes in v5:
- fixed the -Werror=sign-compare in builtin/push.c complaints and also added
  a new commit that fix the remote.h

Range-diff v4 -> v5:
-:  ---------- > 1:  e01126890c remote: fix sign-compare warnings in push_cas_option
1:  20ed79546f = 2:  adbce652e6 remote: move remote group resolution to remote.c
2:  964694e587 ! 3:  a8d5f4b7bd push: support pushing to a remote group
    @@ builtin/push.c: static int git_push_config(const char *k, const char *v,
     +			 const char **refspecs,
     +			 int refspec_nr)
     +{
    -+	int i, result = 0;
    ++	int result = 0;
    ++	size_t i;
     +	struct strvec argv = STRVEC_INIT;
     +
     +	strvec_push(&argv, "push");

Usman Akinyemi (3):
  remote: fix sign-compare warnings in push_cas_option
  remote: move remote group resolution to remote.c
  push: support pushing to a remote group

 Documentation/git-push.adoc |  80 ++++++++++--
 builtin/fetch.c             |  42 ------
 builtin/push.c              | 251 +++++++++++++++++++++++++++++++-----
 remote.c                    |  37 ++++++
 remote.h                    |  16 ++-
 t/meson.build               |   1 +
 t/t5566-push-group.sh       | 160 +++++++++++++++++++++++
 7 files changed, 502 insertions(+), 85 deletions(-)
 create mode 100755 t/t5566-push-group.sh