bugfix: verificar si la rama grupo trackea una rama remota antes de hacer pull

src/git_flow/git.py

@@ -1,5 +1,6 @@
 import subprocess
 
+from git_flow import GitFlowError
 from git_flow.io import *
 
 
@@ -80,6 +81,13 @@ class Git:
     def is_repository() -> bool:
         return Git("rev-parse", is_inside_work_tree=True).code() == 0
 
+    @staticmethod
+    def get_tracking_branch(branch: str) -> str | None:
+        try:
+            return Git("rev-parse", branch + "@{upstream}", abbrev_ref=True).firstline()
+        except subprocess.CalledProcessError:
+            return None
+
     def __init__(self, subcommand: str, *args: str, **kwargs: str | int | bool | list[str] | None) -> None:
         self.command = ["git", subcommand]