From e6d46e8a02385aef303a19de2a1ec00fc99d641e Mon Sep 17 00:00:00 2001
From: Axel Burri <axel@tty0.ch>
Date: Tue, 22 Mar 2016 19:30:12 +0100
Subject: [PATCH] btrbk: fix regression: correctly handle previously received
 subvolumes in get_latest_common()

regression from: 8819c67502501a7f921272ea8b3d8500af5ae7ac
---
 btrbk | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/btrbk b/btrbk
index 39f6025..3000b05 100755
--- a/btrbk
+++ b/btrbk
@@ -1487,13 +1487,12 @@ sub get_latest_common($$$;$)
   my $debug_src = $svol->{URL};
   $debug_src .= "#" . $threshold_gen if($threshold_gen);
 
-  # prefer latest received subvolume as latest common
+  # keep track of already received subvolumes
+  my %receive_target_present;
   if($droot->{SUBVOL_RECEIVED}) {
-    foreach(reverse @{$droot->{SUBVOL_RECEIVED}}) {
-      TRACE "get_latest_common: checking previously received subvolume: $_->{source}->{PRINT}";
+    foreach(@{$droot->{SUBVOL_RECEIVED}}) {
       next if($_->{ERROR});
-      DEBUG("Latest common subvolumes for: $debug_src: src=$_->{source}->{PRINT}  target=$_->{received_subvolume}->{PRINT} (previously received)");
-      return ($_->{source}, $_->{received_subvolume});
+      $receive_target_present{$_->{source}->{node}{uuid}} = $_->{received_subvolume};
     }
   }
 
@@ -1505,6 +1504,12 @@ sub get_latest_common($$$;$)
       next;
     }
 
+    if(my $received_subvol = $receive_target_present{$child->{node}{uuid}}) {
+      # subvolume has been previously received
+      DEBUG("Latest common subvolumes for: $debug_src: src=$child->{PRINT}  target=$received_subvol->{PRINT} (previously received)");
+      return ($child, $received_subvol);
+    }
+
     foreach (get_receive_targets($droot, $child)) {
       DEBUG("Latest common subvolumes for: $debug_src: src=$child->{PRINT}  target=$_->{PRINT}");
       return ($child, $_);