fix(files): use destination path for MKCOL during drag & drop folder upload

[Le-Syl21]

Summary

• Fix drag & drop folder upload: createDirectoryIfNotExists() was called with a path relative to the user's DAV root instead of the destination folder, causing the MKCOL to be skipped entirely and the subsequent PUT to fail with a 404.

Root cause

When dragging folder_to_copy into cmdb/:

1. createDirectoryIfNotExists('/folder_to_copy') checked if /files/user/folder_to_copy existed (the source folder)
2. It returned true → MKCOL was skipped
3. uploader.upload() correctly targeted /files/user/cmdb/folder_to_copy/file.txt via destination.source
4. → 404 Not Found because /cmdb/folder_to_copy/ was never created

The fix prepends destination.path so the existence check and MKCOL target the correct path: /cmdb/folder_to_copy.

Related issues

• Request Method: MKCOL - 405 Method not allowed #17064 — MKCOL 405 on drag & drop folder upload (NC 16)
• [Bug]: Drag&Drop is broken on NC28rc4 again #42136 — Drag & drop broken on NC 28
• [Bug]: Can't drag & drop upload multiple folders and file through Web UI #43954 — Can't drag & drop multiple folders (NC 28)
• [Bug]: 31.0.0 RC2 File Drop folder fails #50584 — File drop folder fails (NC 31)
• [Bug]: Upload folder (drag and drop (windows)) to public link fails #51806 — Drag & drop folder to public link fails (NC 31)
• [Bug]: Drag and drop folder uploads to share links fail (PROPFIND) #57035 — Drag & drop folder uploads fail (NC 32)

Test plan

• Drag & drop a single folder with files into another folder → structure preserved
• Drag & drop nested folders (folder with subfolders) → all levels created
• Drag & drop a folder that already exists at destination → conflict handling works
• Drag & drop multiple folders simultaneously → all created
• Drag & drop to root level → works
• Drag & drop to a deeply nested destination → works
• Import button (file input) still works as before

🤖 Generated with Claude Code

[artonge]

Hello @Le-Syl21, can you share before/after screencast of the issue?
Also, all of the mentioned issues are closed, can you confirm that this is actually solving something?

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