lst: ensure that target changelist exists when updating base revision

EA-115966 - assert: ChangeListWorker.getDataByIdVerify

platform/diff-impl/src/com/intellij/openapi/vcs/ex/DocumentTracker.kt

@@ -184,7 +184,7 @@ class DocumentTracker : Disposable {
     }
   }
 
-  private fun updateFrozenContentIfNeeded() {
+  fun updateFrozenContentIfNeeded() {
     // ensure blocks are up to date
     updateFrozenContentIfNeeded(Side.LEFT)
     updateFrozenContentIfNeeded(Side.RIGHT)

platform/diff-impl/src/com/intellij/openapi/vcs/ex/LineStatusTrackerBase.kt

@@ -94,6 +94,11 @@ abstract class LineStatusTrackerBase<R : Range> {
 
   @CalledInAwt
   fun setBaseRevision(vcsContent: CharSequence) {
+    setBaseRevision(vcsContent, null)
+  }
+
+  @CalledInAwt
+  protected fun setBaseRevision(vcsContent: CharSequence, beforeUnfreeze: (() -> Unit)?) {
     application.assertIsDispatchThread()
     if (isReleased) return
 
@@ -101,6 +106,8 @@ abstract class LineStatusTrackerBase<R : Range> {
       updateDocument(Side.LEFT) {
         vcsDocument.setText(vcsContent)
       }
+
+      beforeUnfreeze?.invoke()
     }
 
     if (!isInitialized) {

platform/vcs-impl/src/com/intellij/openapi/vcs/ex/PartialLocalLineStatusTracker.kt

@@ -144,15 +144,21 @@ class PartialLocalLineStatusTracker(project: Project,
 
   @CalledInAwt
   fun setBaseRevision(vcsContent: CharSequence, changelistId: String?) {
-    currentMarker = if (changelistId != null) ChangeListMarker(changelistId) else null
-    try {
-      setBaseRevision(vcsContent)
-      dropExistingUndoActions()
-    }
-    finally {
-      currentMarker = null
+    setBaseRevision(vcsContent) {
+      if (changelistId != null) {
+        changeListManager.executeUnderDataLock {
+          if (changeListManager.getChangeList(changelistId) != null) {
+            documentTracker.writeLock {
+              currentMarker = ChangeListMarker(changelistId)
+              documentTracker.updateFrozenContentIfNeeded()
+              currentMarker = null
+            }
+          }
+        }
+      }
     }
 
+    dropExistingUndoActions()
     if (isValid()) eventDispatcher.multicaster.onBecomingValid(this)
   }