diff: do not close all split-mode editors for DiffVirtualFile when one editor is closed

platform/diff-impl/src/com/intellij/diff/editor/DiffEditorProvider.kt

@@ -31,13 +31,13 @@ class DiffEditorProvider : AsyncFileEditorProvider, DumbAware {
   override fun createEditorAsync(project: Project, file: VirtualFile): AsyncFileEditorProvider.Builder {
     val builder = (file as DiffVirtualFile).createProcessorAsync(project)
     return object : AsyncFileEditorProvider.Builder() {
-      override fun build() = DiffRequestProcessorEditor(project, file, builder.build())
+      override fun build() = DiffRequestProcessorEditor(file, builder.build())
     }
   }
 
   override fun createEditor(project: Project, file: VirtualFile): FileEditor {
     val builder = (file as DiffVirtualFile).createProcessorAsync(project)
-    return DiffRequestProcessorEditor(project, file, builder.build())
+    return DiffRequestProcessorEditor(file, builder.build())
   }
 
   override fun disposeEditor(editor: FileEditor) {

platform/diff-impl/src/com/intellij/diff/editor/DiffRequestProcessorEditor.kt

@@ -18,26 +18,30 @@ package com.intellij.diff.editor
 import com.intellij.codeHighlighting.BackgroundEditorHighlighter
 import com.intellij.diff.impl.DiffRequestProcessor
 import com.intellij.openapi.Disposable
-import com.intellij.openapi.fileEditor.*
+import com.intellij.openapi.fileEditor.FileEditor
+import com.intellij.openapi.fileEditor.FileEditorLocation
+import com.intellij.openapi.fileEditor.FileEditorState
+import com.intellij.openapi.fileEditor.FileEditorStateLevel
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.Disposer
 import com.intellij.openapi.util.UserDataHolderBase
 import com.intellij.openapi.vfs.VirtualFile
 import java.beans.PropertyChangeListener
+import java.beans.PropertyChangeSupport
 import javax.swing.JComponent
 
 class DiffRequestProcessorEditor(
-  private val project: Project,
   private val file: DiffVirtualFile,
   private val processor: DiffRequestProcessor
 ) : UserDataHolderBase(), FileEditor {
+  private val propertyChangeSupport = PropertyChangeSupport(this)
 
   init {
     Disposer.register(this, Disposable {
       Disposer.dispose(processor)
     })
     Disposer.register(processor, Disposable {
-      FileEditorManager.getInstance(project).closeFile(file)
+      propertyChangeSupport.firePropertyChange(FileEditor.PROP_VALID, true, false)
     })
   }
 
@@ -54,6 +58,14 @@ class DiffRequestProcessorEditor(
 
   override fun deselectNotify() {}
 
+  override fun addPropertyChangeListener(listener: PropertyChangeListener) {
+    propertyChangeSupport.addPropertyChangeListener(listener)
+  }
+
+  override fun removePropertyChangeListener(listener: PropertyChangeListener) {
+    propertyChangeSupport.removePropertyChangeListener(listener)
+  }
+
   //
   // Unused
   //
@@ -63,9 +75,6 @@ class DiffRequestProcessorEditor(
   override fun setState(state: FileEditorState) {}
   override fun isModified(): Boolean = false
 
-  override fun addPropertyChangeListener(listener: PropertyChangeListener) {}
-  override fun removePropertyChangeListener(listener: PropertyChangeListener) {}
-
   override fun getBackgroundHighlighter(): BackgroundEditorHighlighter? = null
   override fun getCurrentLocation(): FileEditorLocation? = null
 }