[meld/meld-3-16] meldbuffer: Don't update recorded disk mtime for errors/missing files

[Kai Willadsen <kaiw src gnome org>]

commit 628f2bb0b8b4c6da9d200877f65a6935a6759a1c
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sun Jul 10 09:44:14 2016 +1000

    meldbuffer: Don't update recorded disk mtime for errors/missing files
    
    Most commonly this is an issue where a file notification event happens
    for a deleted file that is then replaced by an external program. In
    this case we don't want to invalidate our recorded on-disk mtime
    because it's still the last valid time we saw for this file.

 meld/meldbuffer.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/meld/meldbuffer.py b/meld/meldbuffer.py
index 0e7a935..df83f96 100644
--- a/meld/meldbuffer.py
+++ b/meld/meldbuffer.py
@@ -167,7 +167,7 @@ class MeldBufferData(GObject.GObject):
         mtime = self._query_mtime(f)
         if self._disk_mtime and mtime > self._disk_mtime:
             self.emit('file-changed')
-        self._disk_mtime = mtime
+        self._disk_mtime = mtime or self._disk_mtime
 
     @property
     def gfile(self):