Encoding changed during format

[rgilsimoes]

Expected Behavior

I expect the file encoding to remain as UTF-8 after running ktlint with --format option regardless of the characters contained.

Observed Behavior

When the file contains some special characters ktlint changes the file encoding to ANSI

Steps to Reproduce

1. Create a file in intellij with UTF-8 encoding
2. Write a simple variable containing the following character §
3. Close file
4. Run ktlint on the file
5. Open the file on intellij
6. Wrong encoding is used, file is now ANSI encoded

Your Environment

• Version of ktlint used: 1.2.1

• Relevant parts of the .editorconfig settings:
  [{.kt,.kt.ftl}]
  max_line_length = off
  indent_style = space
  indent_size = 2
  ktlint_standard_trailing-comma-on-call-site = disabled
  ktlint_standard_trailing-comma-on-declaration-site = disabled
  ktlint_function_signature_rule_force_multiline_when_parameter_count_greater_or_equal_than = 4
  ktlint_standard_no-empty-first-line-in-class-body = disabled
  ktlint_standard_property-naming = disabled
  ktlint_standard_value-argument-comment = disabled
  ktlint_standard_value-parameter-comment = disabled
  ktlint_standard_no-blank-line-in-list = disabled
  ktlint_standard_filename = disabled
  ij_kotlin_name_count_to_use_star_import = 999
  ij_kotlin_name_count_to_use_star_import_for_members = 999

• Name and version (or code for custom task) of integration used (Gradle plugin, Maven plugin, command line, custom Gradle task): git-format-staged

• Version of Gradle used (if applicable): N/A

• Operating System and version: Windows 11

[paul-dingemans]

Ktlint does not explicit set/change the encoding of the file being written. If the original file starts with a UTF-8 Bom character, this character is guarranteed to be present in the result file as well. Nothing else happens regarding encoding.

Can you please add screendumps? I cannot reproduce the problem, but I might misunderstand what exactly you mean with Write a simple variable containing the following character § as code below is not compilable:

[rgilsimoes]

Hi Paul, that's exactly it.
Here are some samples:

Before ktlint:

After ktlint:

[cgoeller]

This issue also occurs on the latest 1.7.1 ktlint.
It only occurs when using --stdin and --format on Windows (git bash)

Analysis from my side:
ktlint just uses "print" which relies on "System.out" which uses the encoding defined in the system property "stdout.encoding". Default on windows seems to be "cp850"

To avoid the problem one can override the system property on the command line or by changing ktlint to use OutputStreamWriter(System.out, StandardCharsets.UTF_8)

[paul-dingemans]

ktlint just uses "print" which relies on "System.out" which uses the encoding defined in the system property "stdout.encoding". Default on windows seems to be "cp850"

To avoid the problem one can override the system property on the command line or by changing ktlint to use OutputStreamWriter(System.out, StandardCharsets.UTF_8)

Tnx for the suggestion. As the UTF-8 charset is also used when not using flag --stdin it seems valid to me to use OutputStreamWriter(System.out, StandardCharsets.UTF_8) per your suggestion.