From 5d2365f6c4cc388c2d74e43b2c1b7e8fc4c4ab86 Mon Sep 17 00:00:00 2001
From: Daira Hopwood <daira@jacaranda.org>
Date: Sun, 25 Oct 2015 13:19:13 +0000
Subject: [PATCH] Describe use of size=None for deleted files. refs
 ticket:1710.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
---
 docs/proposed/magic-folder/remote-to-local-sync.rst | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/docs/proposed/magic-folder/remote-to-local-sync.rst b/docs/proposed/magic-folder/remote-to-local-sync.rst
index be897259..26f1825d 100644
--- a/docs/proposed/magic-folder/remote-to-local-sync.rst
+++ b/docs/proposed/magic-folder/remote-to-local-sync.rst
@@ -896,10 +896,20 @@ take this as a signal to rename their copies to the backup filename.
 Note that the entry for this zero-length file has a version number as
 usual, and later versions may restore the file.
 
+When the downloader deletes a file (or renames it to a filename
+ending in ``.backup``) in response to a remote change, a local
+filesystem notification will occur, and we must make sure that this
+is not treated as a local change. To do this we have the downloader
+set the ``size`` field in the magic folder db to ``None`` (SQL NULL)
+just before deleting the file, and suppress notifications for which
+the local file does not exist, and the recorded ``size`` field is
+``None``.
+
 When a Magic Folder client restarts, we can detect files that had
 been downloaded but were deleted while it was not running, because
 their paths will have last-downloaded records in the magic folder db
-without any corresponding local file.
+with a ``size`` other than ``None``, and without any corresponding
+local file.
 
 Deletion of a directory
 ~~~~~~~~~~~~~~~~~~~~~~~
-- 
2.45.2