ty: Fix git-config regexp in get_branch_info()

The regexp used to get the branch configuration in get_branch_info()
is subtly wrong. If there are multiple branches starting with the same
prefix, the configuration for all of them will be returned, which can
lead to the wrong branch info being used.

eg. Running b4 -d ty, with extra logging of every line in
get_config_from_git() shows:

  Running git --no-pager config -z --get-regexp branch\.foo\.*
  branch.foo.remote .
  branch.foo.merge refs/heads/foo-test
  branch.foo-test.remote .
  branch.foo-test.merge refs/heads/foo-base

Although the regexp has two escaped dots, the 2nd one is seemingly
consumed by the '*', leading to the regexp matching "foo" and
"foo-test".

This can be observed on the command line:
  $ git branch -t foo origin/master
  $ git branch -t foo-test origin/master
  $ git --no-pager config --get-regexp "branch\.foo\.*"
  branch.foo.remote .
  branch.foo.merge refs/heads/foo-test
  branch.foo-test.remote .
  branch.foo-test.merge refs/heads/foo-base

The real problem is that we meant to pass a regexp of
"branch\.foo\..*", so change the code to use that, which fixes the
problem:

  $ git --no-pager config --get-regexp "branch\.foo\..*"
  branch.foo.remote origin
  branch.foo.merge refs/heads/master

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230310055753.1609529-1-mpe@ellerman.id.au
Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/b4/ty.py b/b4/ty.py
index 4594116..863441e 100644
--- a/b4/ty.py
+++ b/b4/ty.py
@@ -627,7 +627,7 @@ def get_branch_info(gitdir, branch):
 
     BRANCH_INFO = dict()
 
-    remotecfg = b4.get_config_from_git('branch\\.%s\\.*' % branch)
+    remotecfg = b4.get_config_from_git('branch\\.%s\\..*' % branch)
     if remotecfg is None or 'remote' not in remotecfg:
         # Did not find a matching branch entry, so look at remotes
         gitargs = ['remote', 'show']