ez-send: initial support for tagging sent revisions

After we sent off the revision, create the structure in the tree that
would allow us to go back to that revision regardless of what changes we
make to the working branch. This is tricky for the default "commit"
strategy, because we want to remove the cover letter from the history
and store its final version in the tag applied to the tip commit.

For this, we create a detached head, cherry-pick the range without the
cover, and then tag the resulting detached head.

Future work will make it possible to prep and send these as pull
requests.

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

1 files changed, 49 insertions, 1 deletions

diff --git a/b4/ez.py b/b4/ez.py
index 3ffc4a3..3e6581c 100644
--- a/b4/ez.py
+++ b/b4/ez.py
@@ -785,7 +785,7 @@ def cmd_ez_send(cmdargs: argparse.Namespace) -> None:
         topdir = b4.git_get_toplevel()
         getm = os.path.join(topdir, 'scripts', 'get_maintainer.pl')
         if os.access(getm, os.X_OK):
-            logger.debug('Using kernel get_maintainer.pl for to and cc list')
+            logger.info('Using kernel get_maintainer.pl for to and cc lists')
             tocmdstr = f'{getm} --nogit --nogit-fallback --nogit-chief-penguins --norolestats --nol'
             cccmdstr = f'{getm} --nogit --nogit-fallback --nogit-chief-penguins --norolestats --nom'
         if tocmdstr:
@@ -922,6 +922,54 @@ def cmd_ez_send(cmdargs: argparse.Namespace) -> None:
     else:
         logger.info('Sent %s messages', counter)
 
+    mybranch = b4.git_get_current_branch()
+    if get_cover_strategy() == 'commit':
+        # Detach the head at our parent commit and apply the cover-less series
+        cover_commit = find_cover_commit()
+        gitargs = ['checkout', f'{cover_commit}~1']
+        ecode, out = b4.git_run_command(None, gitargs)
+        if ecode > 0:
+            # TODO: do something
+            raise RuntimeError('Could not switch to a detached head')
+        # cherry-pick from cover letter to the last commit
+        last_commit = patches[-1][0]
+        gitargs = ['cherry-pick', f'{cover_commit}..{last_commit}']
+        ecode, out = b4.git_run_command(None, gitargs)
+        if ecode > 0:
+            # TODO: do something
+            raise RuntimeError('Could not cherry-pick the cover-less range')
+        # Find out the head commit
+        gitargs = ['rev-parse', 'HEAD']
+        ecode, out = b4.git_run_command(None, gitargs)
+        if ecode > 0:
+            # TODO: do something
+            raise RuntimeError('Could not find the HEAD commit of the detached head')
+        tagcommit = out.strip()
+        # Switch back to our branch
+        gitargs = ['checkout', mybranch]
+        ecode, out = b4.git_run_command(None, gitargs)
+        if ecode > 0:
+            # TODO: do something
+            raise RuntimeError('Could not switch back to %s', mybranch)
+    else:
+        # TODO: commit-tip will have HEAD~1
+        tagcommit = 'HEAD'
+
+    # TODO: make sent/ prefix configurable?
+    tagprefix = 'sent/'
+    if mybranch.startswith('b4/'):
+        tagname = f'{tagprefix}{mybranch[3:]}-v{revision}'
+    else:
+        tagname = f'{tagprefix}{mybranch}-v{revision}'
+
+    # TODO: check if we already have this tag for some reason
+    logger.info('Tagging %s', tagname)
+    gitargs = ['tag', '-a', '-F', '-', tagname, tagcommit]
+    ecode, out = b4.git_run_command(None, gitargs, stdin=cover.encode())
+    if ecode > 0:
+        # TODO: do something
+        raise RuntimeError('Could not tag %s as %s', tagcommit, tagname)
+
     if not cover_msgid:
         return