[PATCH v5 0/4] fetch: avoid fetching every branch of a new remote in a shallow repo

Avoid fetching every branch of a new remote in a shallow repo.

Changes in v5:

 * Renumber test file from t5585 to t5586.

Changes in v4:

 * Removed the automatic default-branch fetch. A fresh remote fetches
   nothing until you track a branch explicitly.
 * Fixed fetch report showing "new ref HEAD" instead of "new branch "
 * Reworded remote..refmap docs and commit message.

Changes in v3:

 * Replace the special ":"/"+:" fetch refspec with remote.<name>.refmap,
   reusing git's existing --refmap mechanism instead of inventing new
   refspec syntax.
 * Split the change into 4 commits.

Changes in v2:

 * Replaced the opt-in fetch.shallow config entirely with a new special
   fetch refspec (+:) that git remote add now defaults new remotes to in a
   shallow repository. The new refspec fetches whichever branches any local
   branch tracks at that remote, plus the remote's default branch.

Harald Nordgren (4):
  fetch: add remote.<name>.refmap
  fetch: infer branches to fetch from a refmap-only remote
  remote: add "git remote add --limited-fetch"
  remote: default to --limited-fetch in a shallow repository

 Documentation/config/remote.adoc |   8 +++
 Documentation/fetch-options.adoc |   5 ++
 Documentation/git-remote.adoc    |  14 +++-
 builtin/fetch.c                  |  60 +++++++++++++---
 builtin/remote.c                 |  31 ++++++--
 remote.c                         |  41 ++++++++++-
 remote.h                         |   9 +++
 t/meson.build                    |   1 +
 t/t5505-remote.sh                |  76 ++++++++++++++++++++
 t/t5510-fetch.sh                 |  17 +++++
 t/t5586-fetch-refmap.sh          | 119 +++++++++++++++++++++++++++++++
 11 files changed, 363 insertions(+), 18 deletions(-)
 create mode 100755 t/t5586-fetch-refmap.sh

base-commit: a018953688f1b10bddf91bff8747068f5f4746a4
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2412%2FHaraldNordgren%2Ffetch-shallow-narrow-refspec-v5
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2412/HaraldNordgren/fetch-shallow-narrow-refspec-v5
Pull-Request: https://github.com/git/git/pull/2412

Range-diff vs v4:

 1:  d48a7004e4 = 1:  d48a7004e4 fetch: add remote.<name>.refmap
 2:  45b26e2bb2 ! 2:  fecdbc43b8 fetch: infer branches to fetch from a refmap-only remote
     @@ t/meson.build: integration_tests = [
         't5582-fetch-negative-refspec.sh',
         't5583-push-branches.sh',
         't5584-http-429-retry.sh',
     -+  't5585-fetch-refmap.sh',
     ++  't5586-fetch-refmap.sh',
         't5600-clone-fail-cleanup.sh',
         't5601-clone.sh',
         't5602-clone-remote-exec.sh',
      
     - ## t/t5585-fetch-refmap.sh (new) ##
     + ## t/t5586-fetch-refmap.sh (new) ##
      @@
      +#!/bin/sh
      +
 3:  e2f072c254 = 3:  b45f3cf0ab remote: add "git remote add --limited-fetch"
 4:  43b9711a2c = 4:  8c2a144eb7 remote: default to --limited-fetch in a shallow repository