From 5e105c38c79ec617322bdcef78c8daff025c1c95 Mon Sep 17 00:00:00 2001
From: Pierre-Yves Chibon <pingou@pingoured.fr>
Date: Apr 07 2017 12:57:35 +0000
Subject: Make add_file_to_git use a lock as we do for our other git repositories


This is in order to prevent breaking the git history when two requests
are touching the same git repo at the same time.
We had done most of these git calls but looks like we missed this one.

Fixes https://pagure.io/pagure/issue/2200

---

diff --git a/pagure/lib/git.py b/pagure/lib/git.py
index eb404ac..ae7f1b6 100644
--- a/pagure/lib/git.py
+++ b/pagure/lib/git.py
@@ -799,84 +799,89 @@ def add_file_to_git(repo, issue, ticketfolder, user, filename, filestream):
     # Get the fork
     repopath = os.path.join(ticketfolder, repo.path)
 
-    # Clone the repo into a temp folder
-    newpath = tempfile.mkdtemp(prefix='pagure-')
-    new_repo = pygit2.clone_repository(repopath, newpath)
+    lockfile = '%s.lock' % repopath
 
-    folder_path = os.path.join(newpath, 'files')
-    file_path = os.path.join(folder_path, filename)
+    lock = filelock.FileLock(lockfile)
+    with lock:
 
-    # Get the current index
-    index = new_repo.index
+        # Clone the repo into a temp folder
+        newpath = tempfile.mkdtemp(prefix='pagure-')
+        new_repo = pygit2.clone_repository(repopath, newpath)
 
-    # Are we adding files
-    added = False
-    if not os.path.exists(file_path):
-        added = True
-    else:
-        # File exists, remove the clone and return
-        shutil.rmtree(newpath)
-        return os.path.join('files', filename)
+        folder_path = os.path.join(newpath, 'files')
+        file_path = os.path.join(folder_path, filename)
 
-    if not os.path.exists(folder_path):
-        os.mkdir(folder_path)
+        # Get the current index
+        index = new_repo.index
 
-    # Write down what changed
-    filestream.seek(0)
-    with open(file_path, 'w') as stream:
-        stream.write(filestream.read())
+        # Are we adding files
+        added = False
+        if not os.path.exists(file_path):
+            added = True
+        else:
+            # File exists, remove the clone and return
+            shutil.rmtree(newpath)
+            return os.path.join('files', filename)
 
-    # Retrieve the list of files that changed
-    diff = new_repo.diff()
-    files = [patch.new_file_path for patch in diff]
+        if not os.path.exists(folder_path):
+            os.mkdir(folder_path)
 
-    # Add the changes to the index
-    if added:
-        index.add(os.path.join('files', filename))
-    for filename in files:
-        index.add(filename)
+        # Write down what changed
+        filestream.seek(0)
+        with open(file_path, 'w') as stream:
+            stream.write(filestream.read())
 
-    # If not change, return
-    if not files and not added:
-        shutil.rmtree(newpath)
-        return
+        # Retrieve the list of files that changed
+        diff = new_repo.diff()
+        files = [patch.new_file_path for patch in diff]
 
-    # See if there is a parent to this commit
-    parent = None
-    try:
-        parent = new_repo.head.get_object().oid
-    except pygit2.GitError:
-        pass
+        # Add the changes to the index
+        if added:
+            index.add(os.path.join('files', filename))
+        for filename in files:
+            index.add(filename)
 
-    parents = []
-    if parent:
-        parents.append(parent)
+        # If not change, return
+        if not files and not added:
+            shutil.rmtree(newpath)
+            return
 
-    # Author/commiter will always be this one
-    author = pygit2.Signature(
-        name=user.username.encode('utf-8'),
-        email=user.default_email.encode('utf-8')
-    )
+        # See if there is a parent to this commit
+        parent = None
+        try:
+            parent = new_repo.head.get_object().oid
+        except pygit2.GitError:
+            pass
 
-    # Actually commit
-    new_repo.create_commit(
-        'refs/heads/master',
-        author,
-        author,
-        'Add file %s to ticket %s: %s' % (filename, issue.uid, issue.title),
-        new_repo.index.write_tree(),
-        parents)
-    index.write()
+        parents = []
+        if parent:
+            parents.append(parent)
 
-    # Push to origin
-    ori_remote = new_repo.remotes[0]
-    master_ref = new_repo.lookup_reference('HEAD').resolve()
-    refname = '%s:%s' % (master_ref.name, master_ref.name)
+        # Author/commiter will always be this one
+        author = pygit2.Signature(
+            name=user.username.encode('utf-8'),
+            email=user.default_email.encode('utf-8')
+        )
 
-    PagureRepo.push(ori_remote, refname)
+        # Actually commit
+        new_repo.create_commit(
+            'refs/heads/master',
+            author,
+            author,
+            'Add file %s to ticket %s: %s' % (filename, issue.uid, issue.title),
+            new_repo.index.write_tree(),
+            parents)
+        index.write()
 
-    # Remove the clone
-    shutil.rmtree(newpath)
+        # Push to origin
+        ori_remote = new_repo.remotes[0]
+        master_ref = new_repo.lookup_reference('HEAD').resolve()
+        refname = '%s:%s' % (master_ref.name, master_ref.name)
+
+        PagureRepo.push(ori_remote, refname)
+
+        # Remove the clone
+        shutil.rmtree(newpath)
 
     return os.path.join('files', filename)