[C2] Documents are duplicated when importing a backup into an empty course with "Rename" option

[Coussecousse]

Describe
When importing a course backup containing documents into a new, empty course, the system creates duplicate files if the default collision rule ("Rename existing files") is selected. Since the course is empty, no collision should occur, and files should simply be created without renaming or duplication, no ?

To Reproduce

1. Create a backup file of a course with documents in it
2. Create a new course
3. Upload the backup file and ensure the option "Rename existing files" (default) is selected :
4. Navigate to the Documents tool in the new course.

Expected behavior
Files should be imported once (?) as there are no pre-existing files in the target course to trigger a naming conflict.

Screenshots

• Result of documents after importing a backup file and chose the default option (rename) :

• Documents result when chosing "Ecraser les fichiers" in a empty course :

Desktop (please complete the following information):

• OS: Linux Ubuntu 24.04
• Browser : Chrome

Server

• OS: Linux Ubuntu 24.04
• Version of Chamilo: 2
• Version of PHP: 8.3

[christianbeeznest]

It is checked and improved with this commit d886e2f

Thanks for confirmation.

[ywarnier]

I haven't tested it, but the code looks good to me.
@Coussecousse, any opinion on that ?

[Coussecousse]

Hi @ywarnier and @christianbeeznest !

I updated my Chamilo repo and tested the fix, but unfortunately, the issue persists. The original explanation might have been unclear (so sorry), so I have recorded a video to demonstrate the behavior:

Capture.video.du.2026-03-09.16-57-33.webm

Timestamps :
0:00 Showing an empty course with no documents.
0:04 Importing an .mbz file using the "Rename file" option (Note: the same .mbz file is used throughout the procedure).
0:24 Files are duplicated and renamed with the _1 suffix, despite the course being empty.
0:37 Deleting all files.
0:41 Re-importing the .mbz file, but selecting the "Overwrite" option.
1:01 Files are imported correctly without any duplication.

I investigated further and identified the following block in MoodleImport.php:

// Handle name collisions based on $filePolicy
      $findExistingIid = function (string $title) use ($docRepo, $parentRes, $courseEntity, $sessionEntity, $groupEntity): ?int {
          $ex = $docRepo->findCourseResourceByTitle(
              $title,
              $parentRes->getResourceNode(),
              $courseEntity,
              $sessionEntity,
              $groupEntity
          );

          return $ex && method_exists($ex, 'getIid') ? (int) $ex->getIid() : null;
      };

Using dumps, I discovered that a name collision occurs every time (both in "overwrite" and "rename" modes). Is it normal for a collision to be detected even when the course is empty?

The logic then follows this flow:

$existsIid = $findExistingIid($finalTitle);
    if ($existsIid) {
        $DBG('file:collision', ['title' => $finalTitle, 'policy' => $filePolicy]);
        if (FILE_SKIP === $filePolicy) {
            if (isset($legacy->resources['document'][$k])) {
                $legacy->resources['document'][$k]->destination_id = $existsIid;
            }

            continue;
        }
        if (FILE_RENAME === $filePolicy) {
            $pi = pathinfo($baseTitle);
            $name = $pi['filename'] ?? $baseTitle;
            $ext2 = isset($pi['extension']) && '' !== $pi['extension'] ? '.'.$pi['extension'] : '';
            $i = 1;
            while ($findExistingIid($finalTitle)) {
                $finalTitle = $name.'_'.$i.$ext2;
                $i++;
            }
        }
        // FILE_OVERWRITE => let DocumentManager handle it
    }

From what I understand, the core difference is that while FILE_OVERWRITE delegates the resolution to DocumentManager, the FILE_RENAME option performs the renaming immediately within this loop.

I will continue to investigate when I have more time, but perhaps you will identify the root cause before I do !

Best regards!