[PATCH v6 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 v6:

 * Remove leftover reference to deleted default-branch logic in commit
   message.

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: c46c1e37724f0478939de636ab8ea5a89086d532
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2412%2FHaraldNordgren%2Ffetch-shallow-narrow-refspec-v6
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2412/HaraldNordgren/fetch-shallow-narrow-refspec-v6
Pull-Request: https://github.com/git/git/pull/2412

Range-diff vs v5:

 1:  d48a7004e4 = 1:  5c31a51bb7 fetch: add remote.<name>.refmap
 2:  fecdbc43b8 = 2:  74c177e3e2 fetch: infer branches to fetch from a refmap-only remote
 3:  b45f3cf0ab ! 3:  3abcc8915b remote: add "git remote add --limited-fetch"
     @@ Commit message
      
          Give "git remote add" a --limited-fetch option that sets up
          remote.<name>.refmap instead of remote.<name>.fetch, so that
     -    "git fetch <name>" only fetches the branches already tracked, plus
     -    the remote's default branch, as described in the previous commit.
     -    It is rejected together with -t/--track or --mirror, since those
     -    already say explicitly what to fetch.
     +    "git fetch <name>" only fetches the branches already tracked, as
     +    described in the previous commit. It is rejected together with
     +    -t/--track or --mirror, since those already say explicitly what to
     +    fetch.
      
          Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
      
 4:  8c2a144eb7 = 4:  84d192445c remote: default to --limited-fetch in a shallow repository