[geary/cherry-pick-8f4e573e] Merge branch 'mjog/692-dont-serialise-empty-array' into 'mainline'

[Michael Gratton <mjog src gnome org>]

commit 94a84b5d275202fd9d8601b68129b4a9fd087325
Author: Michael Gratton <mike vee net>
Date:   Mon Mar 23 10:31:54 2020 +0000

    Merge branch 'mjog/692-dont-serialise-empty-array' into 'mainline'
    
    Geary.Imap.Serializer: Don't try to serialise empty literal data
    
    Closes #692
    
    See merge request GNOME/geary!453
    
    (cherry picked from commit 8f4e573ef64aaa097a7e085614771bb925e194b4)
    
    2826bf0a Geary.Imap.Serializer: Don't try to serialise empty literal data

 src/engine/imap/transport/imap-serializer.vala | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)
---
diff --git a/src/engine/imap/transport/imap-serializer.vala b/src/engine/imap/transport/imap-serializer.vala
index 36dafca9..549391fc 100644
--- a/src/engine/imap/transport/imap-serializer.vala
+++ b/src/engine/imap/transport/imap-serializer.vala
@@ -106,12 +106,14 @@ public class Geary.Imap.Serializer : BaseObject {
     public async void push_literal_data(uint8[] buffer,
                                         GLib.Cancellable? cancellable = null)
         throws GLib.Error {
-        yield this.output.write_all_async(
-            buffer,
-            Priority.DEFAULT,
-            cancellable,
-            null
-        );
+        if (buffer.length > 0) {
+            yield this.output.write_all_async(
+                buffer,
+                Priority.DEFAULT,
+                cancellable,
+                null
+            );
+        }
     }
 
     /**