Add initial "b4 pr" command set

While working on "pull-request exploder" stuff for achiving on
lore.kernel.org, I realized that this may be a useful set of features
for developers as well, so here is a very simple framework for handing
pull requests. Examples:

b4 pr <msgid>

  - downloads that message
  - parses the pull request
  - checks that the remote tip is where the message says it should be
  - makes sure the base-commit is present in the tree
  - makes sure the tip commit isn't already in one of the branches
  - checks if FETCH_HEAD already is at that commit
  - if the above two checks pass, performs a git fetch

b4 pr --check <msgid>

  Runs all of the checks above, but doesn't perform the actual fetch.
  Useful if you don't remember if you've already processed a pull
  request or not.

b4 pr --explode <msgid>

  Runs basic sanity checks and then:

  - performs a git fetch
  - runs a "git format-patch" for base-commit..FETCH_HEAD
  - adds the same to/from/cc headers as in the pull request
  - properly threads each patch below the pull request
  - saves that into a <msgid>.mbox file

  The above is handy if you want to comment on something in a pull
  request and not have to hunt around for sender/cc information.

Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/b4/command.py b/b4/command.py
index 3997035..f36f3ea 100644
--- a/b4/command.py
+++ b/b4/command.py
@@ -50,6 +50,11 @@ def cmd_verify(cmdargs):
     b4.attest.verify_attestation(cmdargs)
 
 
+def cmd_pr(cmdargs):
+    import b4.pr
+    b4.pr.main(cmdargs)
+
+
 def cmd():
     parser = argparse.ArgumentParser(
         description='A tool to work with public-inbox patches',
@@ -112,6 +117,22 @@ def cmd():
     sp_ver.add_argument('mbox', nargs=1, help='Mbox containing patches to attest')
     sp_ver.set_defaults(func=cmd_verify)
 
+    # b4 pr
+    sp_pr = subparsers.add_parser('pr', help='Fetch a pull request found in a message ID')
+    sp_pr.add_argument('-g', '--gitdir', default=None,
+                       help='Operate on this git tree instead of current dir')
+    sp_pr.add_argument('-b', '--branch', default=None,
+                       help='Check out FETCH_HEAD into this branch after fetching')
+    sp_pr.add_argument('-c', '--check', action='store_true', default=False,
+                       help='Check if pull request has already been applied')
+    sp_pr.add_argument('-e', '--explode', action='store_true', default=False,
+                       help='Convert a pull request into an mbox full of patches')
+    sp_pr.add_argument('-o', '--output-mbox', dest='outmbox', default=None,
+                       help='Save exploded messages into this mailbox (default: msgid.mbx)')
+    sp_pr.add_argument('msgid', nargs='?',
+                       help='Message ID to process, or pipe a raw message')
+    sp_pr.set_defaults(func=cmd_pr)
+
     cmdargs = parser.parse_args()
 
     logger.setLevel(logging.DEBUG)