#!/usr/bin/env python3
"""Fix dulwich history by removing .git directories and updating old timestamps.
Usage: ./fix-history.py <source-branch> <target-branch>
Example: ./fix-history.py master main
"""
import sys
import time
from dulwich.objects import Commit, Tree
from dulwich.repo import Repo
def fix_tree(repo, tree_id, seen_trees=None):
"""Recursively fix a tree by removing .git entries."""
if seen_trees is None:
seen_trees = set()
if tree_id in seen_trees:
return tree_id
seen_trees.add(tree_id)
try:
tree = repo[tree_id]
except KeyError:
return tree_id
if not isinstance(tree, Tree):
return tree_id
# Check if this tree contains .git entries
modified = False
new_items = []
for item in tree.items():
name, mode, sha = item
# Skip .git entries
if name == b".git":
modified = True
continue
# Recursively fix subtrees
if mode == 0o040000: # Directory mode
new_sha = fix_tree(repo, sha, seen_trees)
if new_sha != sha:
modified = True
sha = new_sha
new_items.append((name, mode, sha))
if not modified:
return tree_id
print(f"Removing .git entry from tree {tree_id.decode()}")
# Create new tree without .git entries
new_tree = Tree()
for name, mode, sha in new_items:
new_tree.add(name, mode, sha)
repo.object_store.add_object(new_tree)
return new_tree.id
def fix_commit_dates(commit):
"""Fix commit dates if they're before 1990."""
modified = False
# Unix timestamp for 1990-01-01
min_timestamp = 315532800
max_timestamp = int(time.time())
# Fix author date
if commit.author_time < min_timestamp:
new_time = commit.author_time * 10
if min_timestamp <= new_time <= max_timestamp:
print(f"Fixed author date: {commit.author_time} -> {new_time}")
commit.author_time = new_time
modified = True
# Fix committer date
if commit.commit_time < min_timestamp:
new_time = commit.commit_time * 10
if min_timestamp <= new_time <= max_timestamp:
print(f"Fixed committer date: {commit.commit_time} -> {new_time}")
commit.commit_time = new_time
modified = True
return modified
def rewrite_history(repo, source_branch, target_branch):
"""Rewrite history to fix issues."""
print(f"=== Rewriting history from {source_branch} to {target_branch} ===")
# Get the head commit of the source branch
try:
source_ref = f"refs/heads/{source_branch}".encode()
head_sha = repo.refs[source_ref]
except KeyError:
print(f"Error: Branch '{source_branch}' not found")
return False
# Map old commit SHAs to new ones
commit_map = {}
tree_map = {}
# Get all commits in topological order
walker = repo.get_walker([head_sha])
commits = list(walker)
commits.reverse() # Process from oldest to newest
print(f"Processing {len(commits)} commits...")
for i, commit_entry in enumerate(commits):
old_commit = commit_entry.commit
if i % 100 == 0:
print(f"Processed {i}/{len(commits)} commits...")
# Fix the tree
old_tree_id = old_commit.tree
if old_tree_id not in tree_map:
tree_map[old_tree_id] = fix_tree(repo, old_tree_id)
new_tree_id = tree_map[old_tree_id]
# Create new commit
new_commit = Commit()
new_commit.tree = new_tree_id
new_commit.author = old_commit.author
new_commit.committer = old_commit.committer
new_commit.author_time = old_commit.author_time
new_commit.commit_time = old_commit.commit_time
new_commit.author_timezone = old_commit.author_timezone
new_commit.commit_timezone = old_commit.commit_timezone
new_commit.message = old_commit.message
new_commit.encoding = old_commit.encoding
# note: Drop extra fields
# Fix dates
date_modified = fix_commit_dates(new_commit)
# Map parent commits
new_parents = []
for parent_sha in old_commit.parents:
if parent_sha in commit_map:
new_parents.append(commit_map[parent_sha])
else:
new_parents.append(parent_sha)
new_commit.parents = new_parents
# Check if commit actually changed
if (
new_tree_id == old_tree_id
and not date_modified
and new_parents == list(old_commit.parents)
):
# No changes needed, reuse old commit
commit_map[old_commit.id] = old_commit.id
else:
# Add new commit to object store
repo.object_store.add_object(new_commit)
commit_map[old_commit.id] = new_commit.id
# Update the target branch
new_head = commit_map[head_sha]
target_ref = f"refs/heads/{target_branch}".encode()
repo.refs[target_ref] = new_head
print(
f"✓ Created branch '{target_branch}' with {len([k for k, v in commit_map.items() if k != v])} modified commits"
)
return True
def main():
if len(sys.argv) != 3:
print(f"Usage: {sys.argv[0]} <source-branch> <target-branch>")
print(f"Example: {sys.argv[0]} master main")
print("")
print(
"This will create a new branch <target-branch> with the rewritten history from <source-branch>"
)
sys.exit(1)
source_branch = sys.argv[1]
target_branch = sys.argv[2]
print("=== Dulwich History Fix Script ===")
print("This script will:")
print("1. Remove .git directories from tree objects")
print("2. Fix any commits with dates before 1990")
print(
f"3. Create new branch '{target_branch}' from '{source_branch}' with fixed history"
)
print("")
print(f"Source branch: {source_branch}")
print(f"Target branch: {target_branch}")
print("")
# Open the repository
try:
repo = Repo(".")
except Exception as e:
print(f"Error: Could not open repository: {e}")
sys.exit(1)
# Check if source branch exists
source_ref = f"refs/heads/{source_branch}".encode()
if source_ref not in repo.refs:
print(f"Error: Source branch '{source_branch}' does not exist")
sys.exit(1)
# Check if target branch already exists
target_ref = f"refs/heads/{target_branch}".encode()
if target_ref in repo.refs:
print(f"Error: Target branch '{target_branch}' already exists")
print("Please delete it first or choose a different name")
sys.exit(1)
# Identify problematic trees
print("")
print("=== Identifying problematic trees ===")
bad_trees = []
for sha in repo.object_store:
obj = repo[sha]
if isinstance(obj, Tree):
for name, mode, item_sha in obj.items():
if name == b".git":
bad_trees.append(sha)
break
print(f"Found {len(bad_trees)} trees with .git directories")
# Check for commits with bad dates
print("")
print("=== Identifying problematic commits ===")
bad_dates = []
for sha in repo.object_store:
obj = repo[sha]
if isinstance(obj, Commit):
if obj.commit_time < 315532800 or obj.author_time < 315532800:
bad_dates.append(sha)
print(f"Found {len(bad_dates)} commits with dates before 1990")
# Rewrite history
print("")
if not rewrite_history(repo, source_branch, target_branch):
sys.exit(1)
print("")
print("=== Complete ===")
print(
f"Successfully created branch '{target_branch}' with fixed history from '{source_branch}'"
)
print("")
print("Summary of changes:")
print("- Removed .git directories from tree objects")
print("- Fixed commit timestamps that were before 1990")
print(f"- Created clean history in branch '{target_branch}'")
print("")
print("IMPORTANT NEXT STEPS:")
print(f"1. Review the changes: git log --oneline {target_branch}")
print(
f"2. Compare commit count: git rev-list --count {source_branch} vs git rev-list --count {target_branch}"
)
print("3. If satisfied, you can:")
print(f" - Push the new branch: git push origin {target_branch}")
print(" - Set it as default branch on GitHub/GitLab")
print(f" - Update local checkout: git checkout {target_branch}")
print("")
print(f"The original branch '{source_branch}' remains unchanged.")
if __name__ == "__main__":
main()