Apparently, this use case has been broken for a long time... Since
bb52995f3e (format-patch: introduce format.useAutoBase configuration,
2016-04-26). I'm surprised it's only been reported now.

This patchset fixes the breakage by teaching
`git format-patch --no-base` and making rebase use it.

Changes since v1:

* Update some log messages

Denton Liu (5):
  t3400: demonstrate failure with format.useAutoBase
  format-patch: fix indentation
  t4014: use test_config()
  format-patch: teach --no-base
  rebase: fix format.useAutoBase breakage

 Documentation/git-format-patch.txt |  5 +++--
 builtin/log.c                      | 26 ++++++++++++++++++++++----
 builtin/rebase.c                   |  3 ++-
 t/t3400-rebase.sh                  |  6 ++++++
 t/t4014-format-patch.sh            | 14 +++++++++-----
 5 files changed, 42 insertions(+), 12 deletions(-)

Range-diff against v1:
1:  a1741e5434 ! 1:  4089e51041 t3400: demonstrate failure with format.useAutoBase
    @@ Commit message
     
         Ever since bb52995f3e (format-patch: introduce format.useAutoBase
         configuration, 2016-04-26), `git rebase` has been broken when
    -    `format.useAutoBase = true`. Demonstrate that failure here.
    +    `format.useAutoBase = true`. It fails when rebasing a branch that
    +    doesn't have an upstream set:
    +
    +            fatal: failed to get upstream, if you want to record base commit automatically,
    +            please use git branch --set-upstream-to to track a remote branch.
    +            Or you could specify base commit by --base=<base-commit-id> manually
    +            error:
    +            git encountered an error while preparing the patches to replay
    +            these revisions:
    +
    +                ede2467cdedc63784887b587a61c36b7850ebfac..d8f581194799ae29bf5fa72a98cbae98a1198b12
    +
    +            As a result, git cannot rebase them.
    +
    +    Demonstrate that failure here.
     
         Reported-by: Christian Biesinger [off-list ref]
     
2:  46fd4113aa = 2:  d288d6c3a5 format-patch: fix indentation
3:  22b1fb14f9 ! 3:  196b5d8dbc t4014: use `test_config`
    @@ Metadata
     Author: Denton Liu [off-list ref]
     
      ## Commit message ##
    -    t4014: use `test_config`
    +    t4014: use test_config()
     
         Instead of manually unsetting the config after the test case is done,
    -    use `test_config` to do it automatically. While we're at it, fix a typo
    +    use test_config() to do it automatically. While we're at it, fix a typo
         in a test case name.
     
      ## t/t4014-format-patch.sh ##
4:  e072c36e6a = 4:  f7e5325cc0 format-patch: teach --no-base
5:  15e6ccb203 ! 5:  62c59c12e3 rebase: fix `format.useAutoBase` breakage
    @@ Metadata
     Author: Denton Liu [off-list ref]
     
      ## Commit message ##
    -    rebase: fix `format.useAutoBase` breakage
    +    rebase: fix format.useAutoBase breakage
     
         With `format.useAutoBase = true`, running rebase resulted in an
    -    error when an upstream was't set:
    +    error when an upstream wasn't set:
     
                 fatal: failed to get upstream, if you want to record base commit automatically,
                 please use git branch --set-upstream-to to track a remote branch.
-- 
2.24.0.504.g3cd56eb17d