IDEA-348926 git: better handle changelists during unshelve with an unfinished CLM refresh in progress

Fix the case when the file modification inside 'computeUnderChangeListSync' is picked up by an prior-started CLM refresh,
and is being processed before the 'setDefaultList' command reaches the updater ChangeListWorker(myMainWorker = false).

GitOrigin-RevId: d95c2a0fb5bd3e9821365e93eb00964ff33692c8

platform/vcs-impl/src/com/intellij/openapi/vcs/impl/PartialChangesUtil.kt

@@ -157,6 +157,7 @@ object PartialChangesUtil {
     val changeListManager = ChangeListManagerEx.getInstanceEx(project)
     val oldDefaultList = changeListManager.defaultChangeList
     if (targetChangeList == null ||
+        targetChangeList == oldDefaultList ||
         !changeListManager.areChangeListsEnabled()) {
       if (targetChangeList != null) {
         LOG.debug("Active changelist unchanged: ${targetChangeList.name}")
@@ -164,6 +165,8 @@ object PartialChangesUtil {
       return task.compute()
     }
 
+    waitForChangeListManagerUpdate(project)
+
     switchChangeList(changeListManager, targetChangeList, oldDefaultList)
     val clmConflictTracker = ChangelistConflictTracker.getInstance(project)
     try {
@@ -172,16 +175,20 @@ object PartialChangesUtil {
     }
     finally {
       clmConflictTracker.setIgnoreModifications(false)
-      if (ApplicationManager.getApplication().isReadAccessAllowed) {
-        LOG.warn("Can't wait till changes are applied while holding read lock", Throwable())
-      }
-      else {
-        ChangeListManagerEx.getInstanceEx(project).waitForUpdate()
-      }
+      waitForChangeListManagerUpdate(project)
       restoreChangeList(changeListManager, targetChangeList, oldDefaultList)
     }
   }
 
+  private fun waitForChangeListManagerUpdate(project: Project) {
+    if (ApplicationManager.getApplication().isReadAccessAllowed) {
+      LOG.warn("Can't wait till changes are applied while holding read lock", Throwable())
+    }
+    else {
+      ChangeListManagerEx.getInstanceEx(project).waitForUpdate()
+    }
+  }
+
   private fun switchChangeList(clm: ChangeListManagerEx,
                                targetChangeList: LocalChangeList,
                                oldDefaultList: LocalChangeList) {