[gnome-boxes] downloader: Download to temporary location first

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit d6beb3f587262d477991c86ebe3a211740d8a58e
Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
Date:   Wed Oct 8 18:06:06 2014 +0100

    downloader: Download to temporary location first
    
    Instead of directly downloading to the cached path, download files first
    to a temporary location. The filename has a '~' at the end so its
    obvious that its a not regular file.
    
    This fixes the issue of Boxes trying to use partially downloaded
    files. Currently Boxes doesn't ensure that partially downloaded file is
    deleted before exitting but even if it did, there will always been
    crashes.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=738016

 src/downloader.vala |   19 +++++++++++++++----
 1 files changed, 15 insertions(+), 4 deletions(-)
---
diff --git a/src/downloader.vala b/src/downloader.vala
index e5ddf83..191ee26 100644
--- a/src/downloader.vala
+++ b/src/downloader.vala
@@ -83,9 +83,10 @@ private class Boxes.Downloader : GLib.Object {
         if (cached_file != null)
             return cached_file;
 
-        cached_file = GLib.File.new_for_path (cached_path);
+        var tmp_path = cached_path + "~";
+        var tmp_file = GLib.File.new_for_path (tmp_path);
         debug ("Downloading '%s'...", uri);
-        download = new Download (remote_file, cached_file, progress);
+        download = new Download (remote_file, tmp_file, progress);
         downloads.set (uri, download);
 
         try {
@@ -101,6 +102,10 @@ private class Boxes.Downloader : GLib.Object {
             downloads.remove (uri);
         }
 
+        cached_file = GLib.File.new_for_path (cached_path);
+        tmp_file.move (cached_file, FileCopyFlags.NONE, cancellable);
+        download.cached_file = cached_file;
+
         debug ("Downloaded '%s' and its now locally available at '%s'.", uri, cached_path);
         downloaded (download);
 
@@ -129,7 +134,9 @@ private class Boxes.Downloader : GLib.Object {
             total_num_bytes =  msg.response_headers.get_content_length ();
         });
 
-        var cached_file_stream = yield download.cached_file.create_async (FileCreateFlags.NONE);
+        var cached_file_stream = yield download.cached_file.replace_async (null,
+                                                                           false,
+                                                                           
FileCreateFlags.REPLACE_DESTINATION);
 
         int64 current_num_bytes = 0;
         // FIXME: Reduce lambda nesting by splitting out downloading to Download class
@@ -262,7 +269,11 @@ private class Boxes.Downloader : GLib.Object {
 
         try {
             debug ("Copying '%s' to '%s'..", src_file.get_path (), dest_file.get_path ());
-            yield src_file.copy_async (dest_file, 0, Priority.DEFAULT, cancellable, (current, total) => {
+            yield src_file.copy_async (dest_file,
+                                       FileCopyFlags.OVERWRITE,
+                                       Priority.DEFAULT,
+                                       cancellable,
+                                       (current, total) => {
                 download.progress.progress = (double) current / total;
             });
             debug ("Copied '%s' to '%s'.", src_file.get_path (), dest_file.get_path ());