rebase-branch-from-old: few improvments

- Enhance the documentation
- Allow to revert cherry-pick
- coding style

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1094>

1 files changed, 32 insertions, 16 deletions

diff --git a/scripts/rebase-branch-from-old-module.py b/scripts/rebase-branch-from-old-module.py
index 2e0dbc73be..30676775f6 100755
--- a/scripts/rebase-branch-from-old-module.py
+++ b/scripts/rebase-branch-from-old-module.py
@@ -19,11 +19,12 @@ URL = "https://gitlab.freedesktop.org/"
 PARSER = argparse.ArgumentParser(
     description="`Rebase` a branch from an old GStreamer module onto the monorepo"
 )
-PARSER.add_argument("repo", help="The repo with the old module to use.")
+PARSER.add_argument("repo", help="The repo with the old module to use. ie https://gitlab.freedesktop.org/user/gst-plugins-bad.git or /home/me/gst-build/subprojects/gst-plugins-bad")
 PARSER.add_argument("branch", help="The branch to rebase.")
 
 log_depth = []               # type: T.List[str]
 
+
 @contextmanager
 def nested(name=''):
     global log_depth
@@ -33,18 +34,23 @@ def nested(name=''):
     finally:
         log_depth.pop()
 
+
 def bold(text: str):
     return f"\033[1m{text}\033[0m"
 
+
 def green(text: str):
     return f"\033[1;32m{text}\033[0m"
 
+
 def red(text: str):
     return f"\033[1;31m{text}\033[0m"
 
+
 def yellow(text: str):
     return f"\033[1;33m{text}\033[0m"
 
+
 def fprint(msg, nested=True):
     if log_depth:
         prepend = log_depth[-1] + ' | ' if nested else ''
@@ -128,13 +134,18 @@ class GstCherryPicker:
             self.git("rebase", f"{module}/master",
                 interaction_message=f"Failed rebasing {remote_name}/{self.branch} on {module}/master with:\n"
                 f"   `$ git rebase {module}/master`")
-            self.cherry_pick(tmpbranchname)
-        except:
+            ret = self.cherry_pick(tmpbranchname)
+        except Exception as e:
             self.git("rebase", "--abort", can_fail=True)
             self.git("checkout", prevbranch)
             self.git("branch", "-D", tmpbranchname)
             raise
-        fprint(f"{green(' OK')}\n", nested=False)
+        if ret:
+            fprint(f"{green(' OK')}\n", nested=False)
+        else:
+            self.git("checkout", prevbranch)
+            self.git("branch", "-D", tmpbranchname)
+            fprint(f"{red(' ERROR')}\n", nested=False)
 
     def cherry_pick(self, branch):
         shas = self.git('log', '--format=format:%H', f'{self.module}/master..').strip()
@@ -144,13 +155,17 @@ class GstCherryPicker:
 
         for sha in reversed(shas.split()):
             fprint(f' - Cherry picking: {bold(sha)}\n')
-            self.git("cherry-pick", sha,
-                     interaction_message=f"cherry-picking {sha} onto {branch} with:\n  "
-                                        f" `$ git cherry-pick {sha}`"
-            )
-
+            try:
+                self.git("cherry-pick", sha,
+                        interaction_message=f"cherry-picking {sha} onto {branch} with:\n  "
+                        f" `$ git cherry-pick {sha}`",
+                        revert_operation=["cherry-pick", "--abort"])
+            except Exception as e:
+                fprint(f' - Cherry picking failed: {bold(sha)}\n')
+                return False
+        return True
 
-    def git(self, *args, can_fail=False, interaction_message=None, call=False):
+    def git(self, *args, can_fail=False, interaction_message=None, call=False, revert_operation=None):
         retry = True
         while retry:
             retry = False
@@ -160,7 +175,7 @@ class GstCherryPicker:
                         return subprocess.check_output(["git"] + list(args),
                                                     stdin=subprocess.DEVNULL,
                                                     stderr=subprocess.STDOUT).decode()
-                    except:
+                    except Exception as e:
                         if not can_fail:
                             fprint(f"\n\n{bold(red('ERROR'))}: `git {' '.join(args)}` failed" + "\n", nested=False)
                         raise
@@ -181,7 +196,7 @@ class GstCherryPicker:
                           f"You should then exit with the following codes:\n\n"
                           f"  - {bold('`exit 0`')}: once you have fixed the problem and we can keep moving the \n"
                           f"  - {bold('`exit 1`')}: {bold('retry')}: once you have let the repo in a state where cherry-picking the commit should be to retried\n"
-                          f"  - {bold('`exit 3`')}: stop the script and abandon moving your MRs\n"
+                          f"  - {bold('`exit 2`')}: stop the script and abandon rebasing your branch\n"
                           "\n```\n", nested=False)
                     try:
                         if os.name == 'nt':
@@ -195,9 +210,11 @@ class GstCherryPicker:
                         if e.returncode == 1:
                             retry = True
                             continue
-                        elif e.returncode == 3:
-                            sys.exit(3)
-                    except:
+                        elif e.returncode == 2:
+                            if revert_operation:
+                                self.git(*revert_operation, can_fail=True)
+                        raise
+                    except Exception as e:
                         # Result of subshell does not really matter
                         pass
 
@@ -217,4 +234,3 @@ def main():
 
 if __name__ == '__main__':
     main()
-