Bug 2088: Lag when moving files from remote panel using drag & drop

https://winscp.net/tracker/2088

Source commit: 1aeece432bab5cd65ffab1e44caa649c3a8b508e

source/packages/filemng/DirView.pas

@@ -3244,10 +3244,16 @@ begin
 
               if (Effect = DROPEFFECT_MOVE) or IsRecycleBin then
               try
-                Node := FindNodeToPath(SourcePath);
-                if Assigned(Node) and Assigned(Node.Parent) then
-                  Node := Node.Parent;
-                ValidateDirectory(Node);
+                Node := TryFindNodeToPath(SourcePath);
+                // If the path is not even in the tree, do not bother.
+                // This is particularly for dragging from remote folder, when the source path in %TEMP% and
+                // calling ValidateDirectory would load whole TEMP (and typically also "C:\Users")
+                if Assigned(Node) then
+                begin
+                  if Assigned(Node.Parent) then
+                    Node := Node.Parent;
+                  ValidateDirectory(Node);
+                end;
               except
               end;
             end;

source/packages/filemng/DriveView.pas

@@ -219,6 +219,7 @@ type
     function NodePathExists(Node: TTreeNode): Boolean; override;
     function NodeColor(Node: TTreeNode): TColor; override;
     function FindPathNode(Path: string): TTreeNode; override;
+    function DoFindNodeToPath(Path: string; ExistingOnly: Boolean): TTreeNode;
     function CreateNode: TTreeNode; override;
 
     function DDSourceEffects: TDropEffectSet; override;
@@ -258,6 +259,7 @@ type
     {Node handling:}
     procedure SetImageIndex(Node: TTreeNode); virtual;
     function FindNodeToPath(Path: string): TTreeNode;
+    function TryFindNodeToPath(Path: string): TTreeNode;
     function RootNode(Node: TTreeNode): TTreeNode;
     function GetDirName(Node: TTreeNode): string;
     function GetDisplayName(Node: TTreeNode): string;
@@ -1653,7 +1655,7 @@ begin {ScanDrive}
   end;
 end; {ScanDrive}
 
-function TDriveView.FindNodeToPath(Path: string): TTreeNode;
+function TDriveView.DoFindNodeToPath(Path: string; ExistingOnly: Boolean): TTreeNode;
 
   function SearchSubDirs(ParentNode: TTreeNode; Path: string): TTreeNode; forward;
 
@@ -1676,7 +1678,7 @@ function TDriveView.FindNodeToPath(Path: string): TTreeNode;
       SetLength(Dir, Pred(Length(Dir)));
 
     Node := ParentNode.GetFirstChild;
-    if not Assigned(Node) then
+    if (not Assigned(Node)) and (not ExistingOnly) then
     begin
       ValidateDirectoryEx(ParentNode, rsRecursiveExisting, True);
       Node := ParentNode.GetFirstChild;
@@ -1706,7 +1708,7 @@ function TDriveView.FindNodeToPath(Path: string): TTreeNode;
     Result := nil;
     if Length(Path) > 0 then
     begin
-      if not TNodeData(ParentNode.Data).Scanned then
+      if (not TNodeData(ParentNode.Data).Scanned) and (not ExistingOnly) then
       begin
         ReadSubDirs(ParentNode, GetDriveTypetoNode(ParentNode));
       end;
@@ -1764,7 +1766,7 @@ begin {FindNodeToPath}
     end;
     if Length(Path) > 0 then
     begin
-      if not GetDriveStatus(Drive).Scanned then
+      if (not GetDriveStatus(Drive).Scanned) and (not ExistingOnly) then
       begin
         ScanDrive(Drive);
       end;
@@ -1774,6 +1776,16 @@ begin {FindNodeToPath}
   end;
 end; {FindNodetoPath}
 
+function TDriveView.FindNodeToPath(Path: string): TTreeNode;
+begin
+  Result := DoFindNodeToPath(Path, False);
+end;
+
+function TDriveView.TryFindNodeToPath(Path: string): TTreeNode;
+begin
+  Result := DoFindNodeToPath(Path, True);
+end;
+
 function TDriveView.CheckForSubDirs(Path: string): Boolean;
 var
   DosError: Integer;
@@ -2593,7 +2605,7 @@ var
   SourceParentPath: string;
   SourceIsDirectory: Boolean;
   SaveCursor: TCursor;
-  TargetNode: TTreeNode;
+  SourceNode, TargetNode: TTreeNode;
   TargetPath: string;
   IsRecycleBin: Boolean;
 begin
@@ -2652,7 +2664,10 @@ begin
     {Update source directory, if move-operation was performed:}
     if ((Effect = DROPEFFECT_MOVE) or IsRecycleBin) then
     begin
-      ValidateDirectory(FindNodeToPath(SourceParentPath));
+      // See comment in corresponding operation in TDirView.PerformDragDropFileOperation
+      SourceNode := TryFindNodeToPath(SourceParentPath);
+      if Assigned(SourceNode) then
+        ValidateDirectory(SourceNode);
     end;
 
     {Update subdirectories of target directory:}