[pve-devel] [PATCH qemu-server] Fix #1999: regression for corner cases

[Rhonda D'Vine]

This commit addresses the following things:

* There can be multiple independent snapshot tree roots, display them
  all
* If a snapshot defines a parent that doesn't exist, it is now
  considered a snapshot root

There is a potential issue (which was also before and also affects the
GUI): circular snapshot trees.  That plays into the second mentioned
issue above.  If you manage to have a snapshot that defines a
non-existing root in the config, and then create a snapshot with that
exact name as a child of that snapshot, it would create a circular
dependency.  This would have to get addressed in the GUI too.

Signed-off-by: Rhonda D'Vine <rhonda at proxmox.com>
---
 PVE/CLI/qm.pm | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/PVE/CLI/qm.pm b/PVE/CLI/qm.pm
index 87b97ce..b5e838e 100755
--- a/PVE/CLI/qm.pm
+++ b/PVE/CLI/qm.pm
@@ -926,12 +926,13 @@ our $cmddef = {
 
 			my $snapshots = { map { $_->{name} => $_ } @$res };
 
-			my $root;
+			my @roots;
 			foreach my $e (@$res) {
-			    if (my $parent = $e->{parent}) {
+			    my $parent;
+			    if (($parent = $e->{parent}) && defined $snapshots->{$parent}) {
 				push @{$snapshots->{$parent}->{children}}, $e->{name};
 			    } else {
-				$root = $e->{name};
+				push @roots, $e->{name};
 			    }
 			}
 
@@ -967,7 +968,9 @@ our $cmddef = {
 			    }
 			};
 
-			$snapshottree->('`->', $root, $snapshots);
+			foreach my $root (sort $snaptimesort @roots) {
+			    $snapshottree->('`->', $root, $snapshots);
+			}
 		    }],
 
     rollback => [ "PVE::API2::Qemu", 'rollback', ['vmid', 'snapname'], { node => $nodename } , $upid_exit ],
-- 
2.11.0