Fix folder path escaping for names containing slashes

[ako]

Summary

Fixes issue mendixlabs#1367 where marketplace update --save-edits followed by exec corrupted folder paths containing literal / characters in folder names. The issue occurred because folder names were joined with bare / separators, making it impossible to distinguish between a single folder named "Private - String en/de-cryption" and two nested folders "Private - String en" and "de-cryption".

Changes

• New package mdl/folderpath: Implements escaping and unescaping of folder path segments

  • Join(): Renders folder names as a path, escaping / as \/ and \ as \\ within names
  • Escape(): Escapes a single folder name
  • Split(): Parses a path back into folder names, treating \/ and \\ as escaped characters
  • Lenient reading: backslash before any character other than / or \ is kept literal, preserving backward compatibility with hand-written paths

• Updated folder path handling across executor:

  • hierarchy.go: BuildFolderPath() now uses folderpath.Join() to escape names
  • cmd_folders.go, cmd_microflows_build.go, cmd_pages_builder.go, helpers.go: Updated to use folderpath.Split() instead of naive strings.Split()
  • cmd_constants.go: Refactored to use new describeFolderClause() helper
  • document_placement.go: describeFolderClause() now uses mdlQuote() for proper string literal quoting

• CLI integration (cmd/mxcli/project_tree.go):

  • getOrCreateFolder() now escapes folder names when building paths
  • splitFolderPath() delegates to folderpath.Split()

• Documentation (docs-site/src/reference/organization/create-folder.md):

  • Added section explaining escaping syntax with example

• Test coverage:

  • mdl/folderpath/folderpath_test.go: Round-trip tests, backward compatibility, and edge cases
  • mdl/executor/folder_path_slash_test.go: Integration test verifying describe→exec round-trip with slashes in folder names
  • mdl-examples/bug-tests/1367-folder-name-containing-slash.mdl: Reproducible test case

Implementation Details

The escape mechanism uses backslash (\) as the escape character:

• \/ inside a segment represents a literal /
• \\ inside a segment represents a literal \
• A backslash before any other character is treated as a literal backslash (backward compatible)

This approach works across both MDL string literal quoting rules because \/ is unambiguous under both language versions. The escaping is at the path level, not the string literal level, so DESCRIBE output is properly round-trippable.

https://claude.ai/code/session_01Cj4DQ8PRitHdtF3q8pVVBQ