From 05a4285f54feb076b22e71a13a777837546a78f5 Mon Sep 17 00:00:00 2001
From: Unrud <unrud@openaliasbox.org>
Date: Fri, 5 Aug 2016 17:17:37 +0200
Subject: [PATCH 1/3] Durable creation of intermediate directories

---
 radicale/storage.py | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/radicale/storage.py b/radicale/storage.py
index d14797f..e70028c 100644
--- a/radicale/storage.py
+++ b/radicale/storage.py
@@ -406,6 +406,19 @@ class Collection(BaseCollection):
                 return file_name
         raise FileExistsError(errno.EEXIST, "No usable file name found")
 
+    @classmethod
+    def _makedirs_synced(cls, filesystem_path, exist_ok=False):
+        if os.path.isdir(filesystem_path) and exist_ok:
+            return
+        parent_filesystem_path = os.path.dirname(filesystem_path)
+        # Prevent infinite loop
+        if filesystem_path != parent_filesystem_path:
+            # Create parent dirs recursively
+            cls._makedirs_synced(parent_filesystem_path, exist_ok=True)
+        # Possible race!
+        os.makedirs(filesystem_path, exist_ok=exist_ok)
+        sync_directory(parent_filesystem_path)
+
     @classmethod
     def discover(cls, path, depth="0"):
         if path is None:
@@ -476,11 +489,11 @@ class Collection(BaseCollection):
         if not props.get("tag") and collection:
             props["tag"] = collection[0].name
         if not props:
-            os.makedirs(filesystem_path, exist_ok=True)
+            cls._makedirs_synced(filesystem_path, exist_ok=True)
             return cls(sane_path, principal=principal)
 
         parent_dir = os.path.dirname(filesystem_path)
-        os.makedirs(parent_dir, exist_ok=True)
+        cls._makedirs_synced(parent_dir, exist_ok=True)
 
         # Create a temporary directory with an unsafe name
         with TemporaryDirectory(
@@ -679,8 +692,7 @@ class Collection(BaseCollection):
             if not cls._lock_file:
                 folder = os.path.expanduser(
                     cls.configuration.get("storage", "filesystem_folder"))
-                if not os.path.exists(folder):
-                    os.makedirs(folder, exist_ok=True)
+                cls._makedirs_synced(folder, exist_ok=True)
                 lock_path = os.path.join(folder, ".Radicale.lock")
                 cls._lock_file = open(lock_path, "w+")
                 # Set access rights to a necessary minimum to prevent locking

From 6c3e59fd11400734a8b9ec9942858724a36e3f1d Mon Sep 17 00:00:00 2001
From: Unrud <unrud@openaliasbox.org>
Date: Fri, 5 Aug 2016 17:19:57 +0200
Subject: [PATCH 2/3] Make sure that the root collection exists.

Since the collections are not directly in **filesystem_path** anymore,
the folder is not created by ``Collection.acquire_lock``.
---
 radicale/storage.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/radicale/storage.py b/radicale/storage.py
index e70028c..cab6641 100644
--- a/radicale/storage.py
+++ b/radicale/storage.py
@@ -262,6 +262,8 @@ class BaseCollection:
 
         The ``path`` is relative.
 
+        The root collection "/" must always exist.
+
         """
         raise NotImplementedError
 
@@ -433,6 +435,8 @@ class Collection(BaseCollection):
 
         # Try to guess if the path leads to a collection or an item
         folder = cls._get_collection_root_folder()
+        # Create the root collection
+        cls._makedirs_synced(folder, exist_ok=True)
         try:
             filesystem_path = path_to_filesystem(folder, sane_path)
         except ValueError:

From 07dc71fd73228ea327bb36c275516782663dfcf4 Mon Sep 17 00:00:00 2001
From: Unrud <unrud@openaliasbox.org>
Date: Fri, 5 Aug 2016 17:22:21 +0200
Subject: [PATCH 3/3] Update comment

---
 radicale/storage.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/radicale/storage.py b/radicale/storage.py
index cab6641..34e7a90 100644
--- a/radicale/storage.py
+++ b/radicale/storage.py
@@ -433,7 +433,6 @@ class Collection(BaseCollection):
         if not attributes[0]:
             attributes.pop()
 
-        # Try to guess if the path leads to a collection or an item
         folder = cls._get_collection_root_folder()
         # Create the root collection
         cls._makedirs_synced(folder, exist_ok=True)
@@ -443,6 +442,7 @@ class Collection(BaseCollection):
             # Path is unsafe
             return
 
+        # Check if the path exists and if it leads to a collection or an item
         if not os.path.isdir(filesystem_path):
             if attributes and os.path.isfile(filesystem_path):
                 href = attributes.pop()