Project download fails on Windows if project contains a folder with whitespace at the end of the folder name

[raherin]

If a project contains a folder that has whitespace at the end of the folder name, the project will fail to download or sync on Windows machines. The issue is that Android, iOS and Linux support whitespace at the end of folder names so a project could contain such folders if they were created on a different OS or created by a photo naming expression where a subfolder is created based on the value of another field. When the project is downloaded in Windows, the OS automatically strips the whitespace from the photo name, resulting in an Unhandled Exception error.

To recreate the issue, download the attached project to a non-Windows machine.

-Unzip and open the project in QGIS
-Upload the project as a new project using the Mergin Maps QGIS Plugin
-Open QGIS on a Windows machine and try to download the project

You should get an error similar to the following:

2025-04-29 17:50:45,619 --- version: Python-client/0.10.0 Plugin/2025.1.1 QGIS/3.40.5 (Windows/11)
2025-04-29 17:50:45,619 --- start download support/folder_error
2025-04-29 17:50:45,839 got project info. version v2
2025-04-29 17:50:45,839 will download 3 files in 3 chunks, total size 3607529
2025-04-29 17:50:45,839 Downloading survey.gpkg version=v2 diff=False part=0
2025-04-29 17:50:45,839 Downloading folder_error.qgz version=v2 diff=False part=0
2025-04-29 17:50:45,839 Downloading photos /IMG_20231127_084655.jpg version=v2 diff=False part=0
2025-04-29 17:50:46,079 Download finished: folder_error.qgz
2025-04-29 17:50:46,079 Download finished: photos /IMG_20231127_084655.jpg
2025-04-29 17:50:46,094 Download finished: survey.gpkg
2025-04-29 17:50:46,350 Error while downloading project: Traceback (most recent call last):
  File "C:\PROGRA~1\QGIS34~1.5\apps\Python312\Lib\concurrent\futures\thread.py", line 59, in run
    result = self.fn(*self.args, **self.kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users/raahe/AppData/Roaming/QGIS/QGIS3\profiles\MM_support/python/plugins\Mergin\mergin\client_pull.py", line 95, in _do_download
    item.download_blocking(mc, mp, project_path)
  File "C:\Users/raahe/AppData/Roaming/QGIS/QGIS3\profiles\MM_support/python/plugins\Mergin\mergin\client_pull.py", line 324, in download_blocking
    save_to_file(resp, self.download_file_path)
  File "C:\Users/raahe/AppData/Roaming/QGIS/QGIS3\profiles\MM_support/python/plugins\Mergin\mergin\utils.py", line 39, in save_to_file
    with open(path, "wb") as output:
         ^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: 'C:\\Users\\raahe\\Documents\\Projects\\folder_error\\folder_error\\photos \\IMG_20231127_084655.jpg.0'

2025-04-29 17:50:46,350 --- download aborted

folder_error.zip

[tomasMizera]

We implemented several fixes on mobile to mitigate this, but there are still some scenarios when this might occur

[varmar05]

@DanChov Do we have some guide for users how to fix currently broken projects?

[MarcelGeo]

@harminius double check server for whitespaces.

[RastoHu]

Testing notes:

1. Fix error when creating project with trailing whitespace in folder name #827 is OK. Tested on macOS and there was a warning when creating new project in QGIS plugin and trying to store it to the folder with whitespace at the end of folder name. Also the Finish button was disabled. QASE TC updated as well.
2. Refuse trailing whitespace in path server#534 This PR was not merged so I am unable to test sync process in plugin if folder with whitespace is present. Steps (macOS):
   a. download and unzip project folder_error.zip
   b. create new project in QGIS plugin and copy files and folders from folder_error to new project
   c. sync -> Error?
3. @MarcelGeo @DanChov What about validating whitespace at the end of folder name in custom photo naming? Without it you can prepare folder with trailing space on windows:
   a. create new project
   b. add custom photo name and copy: 'photos /' + @layer_name + '_' + format_date(now(),'ddMMyy_hhmm')
   c. save and sync
   d. open project in mobile app and record point with photo
   e. sync mobile app and in plugin -> error?

General notes:

@MarcelGeo

1. Space at the beginning of a folder name does not cause project problems on Windows. Space is at the beginning of folder "at_beginning": project2/subfolder/ at_begining/space_at_beginning Survey 191125_1253.jpg
2. Space at the beginning of a file name is validated

3. unable to add trailing space to file name. I tried with photo file name, but do not find a way how to add space after the file extension

[harminius]

Re the 2nd point, I think:

• we could add validation to the photo name preview
• mobile could sanitize the photo path - strip the whitespaces @tomasMizera