[PATCH b4 v2 23/44] review-tui: only put back a branch b4 checked out itself

The branch recorded at startup was checked back out at exit even when
the user moved HEAD themselves from another terminal sharing the
worktree. Only undo a checkout that landed on a review branch, the
only kind either app makes.

Signed-off-by: Christian Brauner (Amutable) <[email protected]>
---
 src/b4/review_tui/_entry.py      | 10 +++++++++-
 src/b4/review_tui/_review_app.py |  7 +++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/b4/review_tui/_entry.py b/src/b4/review_tui/_entry.py
index ece97da..6dc71a4 100644
--- a/src/b4/review_tui/_entry.py
+++ b/src/b4/review_tui/_entry.py
@@ -174,9 +174,17 @@ def run_tracking_tui(
         # This covers two cases:
         # - ReviewApp checked out the review branch (shell suspend/agent)
         # - TrackingApp checked out a new series via create_review_branch
+        # Both land on a review branch, and that is the only case we may undo.
+        # Anything else means the user moved HEAD themselves -- possibly hours
+        # ago, from another terminal sharing this worktree -- and the branch
+        # recorded when we started is stale, not something to check back out.
         if original_branch:
             current = b4.git_get_current_branch(topdir)
-            if current and current != original_branch:
+            if (
+                current
+                and current != original_branch
+                and current.startswith(b4.review.REVIEW_BRANCH_PREFIX)
+            ):
                 logger.info(
                     'Checking out %s and starting tracking UI...', original_branch
                 )
diff --git a/src/b4/review_tui/_review_app.py b/src/b4/review_tui/_review_app.py
index 778a8f6..0982f55 100644
--- a/src/b4/review_tui/_review_app.py
+++ b/src/b4/review_tui/_review_app.py
@@ -2164,6 +2164,13 @@ class ReviewApp(LoreNodeShutdownMixin, CheckRunnerMixin, App[None]):
         """Switch back to the original branch after shell/agent use."""
         if not self.branch_checked_out or not self._original_branch:
             return
+        # Only undo our own checkout. If HEAD is no longer on the review
+        # branch we left it on, something else moved it -- the shell we just
+        # suspended into, or another terminal in the same worktree -- and it
+        # is not ours to move back.
+        if b4.git_get_current_branch(self._topdir) != self._branch:
+            self.branch_checked_out = False
+            return
         ecode, _out = b4.git_run_command(
             self._topdir, ['checkout', self._original_branch], logstderr=True
         )

-- 
2.53.0