From 8e8339609ba970f91e29e5ed6900c1fcde0667b6 Mon Sep 17 00:00:00 2001
From: Frederic Devernay <frederic.devernay@m4x.org>
Date: Tue, 23 Mar 2021 16:45:12 -0700
Subject: [PATCH] NodeSerialization: always serialize nodes with an expression

fixes https://github.com/NatronGitHub/Natron/issues/585
---
 Engine/NodeSerialization.cpp | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Engine/NodeSerialization.cpp b/Engine/NodeSerialization.cpp
index 16bb9677cc..50ea1bcf52 100644
--- a/Engine/NodeSerialization.cpp
+++ b/Engine/NodeSerialization.cpp
@@ -100,17 +100,21 @@ NodeSerialization::NodeSerialization(const NodePtr & n,
                     break;
                 }
             }
-            if (!knobs[i]->getIsPersistent() && !hasExpr) {
-                continue;
-            }
+            // Always serialize nodes that have an expression or a link.
+            // See https://github.com/NatronGitHub/Natron/issues/585
+            // Already fixed in RB-3.0 by https://github.com/NatronGitHub/Natron/commit/7ef38849fe
+            if (!hasExpr) {
+                if ( !knobs[i]->getIsPersistent() ) {
+                    continue;
+                }
 
-            if (!knobs[i]->hasModificationsForSerialization()) {
-                continue;
+                if ( !knobs[i]->hasModificationsForSerialization() ) {
+                    continue;
+                }
             }
 
             KnobSerializationPtr newKnobSer = boost::make_shared<KnobSerialization>(knobs[i]);
             _knobsValues.push_back(newKnobSer);
-
         }
 
         _nbKnobs = (int)_knobsValues.size();