PyREPL: Send code using bracketed paste markers

[Eduardo Villalpando Mello (edvilme)]

Fixes #26176.

Problem

On Python 3.13+, using Shift+Enter to run selected/multiline code in the integrated terminal progressively increased the indentation of continuation lines, eventually raising IndentationError: unexpected indent (regression observed in 2026.6.0).

Root cause

The new Python 3.13 PyREPL auto-indents interactively typed input. Terminal REPL code is delivered via terminal.sendText(...) and never shellIntegration.executeCommand(...) (the Python path in TerminalService.executeCommand returns early), so bracketed paste markers are the only thing that tells the PyREPL "this is pasted text — preserve its whitespace".

CodeExecutionHelper.normalizeLines only attached those markers when shell integration was disabled:

if (object.attach_bracket_paste && !shellIntegrationEnabled && _replType === ReplType.terminal)

But the PyREPL stays active even when shell integration is enabled — shell integration is provided from inside Python via PYTHONSTARTUP / pythonrc.py, which makes the REPL's own PS1 emit OSC 633 sequences (the pink/violet >>> users noticed). So with shell integration on (the default), the markers were skipped, raw multiline code was typed into the auto-indenting REPL, and indentation grew line by line.

Fix

Attach bracketed paste for Python 3.13+ terminal sends regardless of the terminal.shellIntegration.enabled setting, since terminal REPL input always goes through sendText:

if (object.attach_bracket_paste && _replType === ReplType.terminal)

The now-unused shellIntegrationEnabled lookup was removed.

Changes

• src/client/terminals/codeExecution/helper.ts — drop the !shellIntegrationEnabled guard so bracketed paste is applied for the 3.13+ PyREPL in the terminal whether or not shell integration is enabled; remove the unused setting read.
• src/test/terminals/codeExecution/helper.test.ts — replace the obsolete "BASIC_REPL does not attach bracketed paste" test (which only passed because reading settings.terminal.shellIntegration threw and hit the catch) with a Shift+Enter progressively changes indentation when running Python code in the terminal #26176 regression test asserting that multiline, indented code sent to a 3.13+ terminal REPL is wrapped in bracketed paste, with indentation preserved verbatim, even when shell integration is enabled.

Note

This supersedes the earlier approach of wrapping inside TerminalService directly, which double-wrapped PyREPL users (the helper already wraps) and risked sending bracketed-paste markers to non-PyREPL interpreters. Those service.ts / service.unit.test.ts changes are reverted.

[Anthony Kim (anthonykim1)]

I don't recall exact detail, but the indentation logic has been funky and probably worth revisiting with newer models. Maybe there were some nuances with PY_REPL flag + shell integration combination.

Also recommend these 4 scenarios when it comes to manually testing and ensuring coverage for run selection of Python code (via shift+enter, or UI):

When I say shell integration, I mean both the terminal.integrated.shellIntegration.enabled and python.terminal.shellIntegration.enabled

1. >= Python3.13 with shell integration enabled.
2. < Python 3.13 with shell integration enabled.
3. >= Python3.13 with shell integration disabled.
4. < Python 3.13 with shell integration disabled.

[Eduardo Villalpando Mello (edvilme)]

>=3.13 with shell integration enabled

>=3.13 with shell integration disabled

< 3.13 with shell integration disabled

< 3.13 with shell integration enabled