From 837a03a317fe9c14ff04b44b0330d43cad4ff1d8 Mon Sep 17 00:00:00 2001
From: Anjal Doshi <anjaldoshi09@gmail.com>
Date: Fri, 20 Oct 2023 15:38:52 -0700
Subject: [PATCH] Fix a crash when undoing AddProcessor Happened when the
 processor being removed has a merger as the destination node

---
 .../ProcessorGraph/ProcessorGraphActions.cpp   | 18 +++++++++++++++++-
 .../ProcessorGraph/ProcessorGraphActions.h     |  2 ++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/Source/Processors/ProcessorGraph/ProcessorGraphActions.cpp b/Source/Processors/ProcessorGraph/ProcessorGraphActions.cpp
index 214c17a7f..2f13581b7 100644
--- a/Source/Processors/ProcessorGraph/ProcessorGraphActions.cpp
+++ b/Source/Processors/ProcessorGraph/ProcessorGraphActions.cpp
@@ -54,6 +54,8 @@ AddProcessor::AddProcessor(Plugin::Description description_,
         destNodeId = destProcessor->getNodeId();
     else
         destNodeId = -1;
+    
+    mergerPath = -1;
 }
 
 AddProcessor::~AddProcessor()
@@ -90,6 +92,13 @@ bool AddProcessor::perform()
     if (processor != nullptr)
     {
         nodeId = processor->getNodeId();
+        
+        if (destProcessor != nullptr && destProcessor->isMerger())
+        {
+            Merger* merger = (Merger*)destProcessor;
+            mergerPath = merger->getSourceNode(0)->getNodeId() == nodeId ? 0 : 1;
+        }
+
         return true;
     }
     else
@@ -98,7 +107,7 @@ bool AddProcessor::perform()
 
 bool AddProcessor::undo()
 {
-    LOGD("Undoing ADD for processor ", nodeId);
+    LOGDD("Undoing ADD for processor ", nodeId);
 
     Array<GenericProcessor*> processorToDelete;
     
@@ -108,6 +117,13 @@ bool AddProcessor::undo()
     if (settings != nullptr)
         delete settings;
     
+    GenericProcessor* destProcessor = processor->getDestNode();
+    if (mergerPath != -1 && destProcessor != nullptr && destProcessor->isMerger())
+    {
+        Merger* merger = (Merger*)destProcessor;
+        merger->switchIO(mergerPath);
+    }
+    
     if (processor != nullptr)
     {
         settings = processorGraph->createNodeXml(processor, false);
diff --git a/Source/Processors/ProcessorGraph/ProcessorGraphActions.h b/Source/Processors/ProcessorGraph/ProcessorGraphActions.h
index 29fe6bf2b..8132f8555 100644
--- a/Source/Processors/ProcessorGraph/ProcessorGraphActions.h
+++ b/Source/Processors/ProcessorGraph/ProcessorGraphActions.h
@@ -65,6 +65,8 @@ class AddProcessor : public UndoableAction
     bool signalChainIsLoading;
     
     int nodeId;
+
+    int mergerPath;
     
     Plugin::Description description;