fix(parser): heredoc backslash escapes; read without -r

[chaliy]

Requested by Михайло · project thread

What changed

• Unquoted heredoc bodies handle backslashes like bash. \$, \` and \\ are literal, \<newline> joins lines (also inside $((…))), other backslashes stay, and backtick substitution runs.
• read without -r removes backslashes. An escaped IFS character stays inside its field (read a b <<< 'x\ y z' gives a='x y'), and \<newline> joins the next line.
• read returns 1 when input ends before the delimiter but still assigns the data (printf abc | read v). An empty stdin returns 1.
• A read from a shared pipe ({ read; read; }, while read) now consumes one record that honours -d, -n and continuation. Before, it always took one line.

Why

Oracle failures shell/heredoc-expand and shell/read-options from the pseudo-linus list.

Before / After

Script	Before	After (= bash 5.2)
heredoc line literal \$user e \crase``	literal \agente e \crase``	literal $user e `crase`
heredoc line `echo bt`	`echo bt`	bt
read a <<< 'barra\invertida'	barra\invertida	barrainvertida
read nada < /dev/null; echo $?	0	1
printf 'a;b' | { read -d ';' p; read -d ';' q; echo $p $q; }	first read took the whole line	a b

New spec heredoc-read-escapes.test.sh has 5 cases, all verified against bash. Read unit tests that fed unterminated input and expected status 0 now pass newline-terminated input, since bash returns 1 for unterminated input.

Risk

Medium. read status at EOF changes for unterminated input, matching bash; the while read || [ -n "$l" ] idiom keeps working (covered). All lib, integration and bash_comparison tests pass.

Checklist

• Tests (spec, verified against bash)
• cargo fmt, cargo clippy -D warnings
• lib, integration and bash_comparison tests
• Docs (compatibility.md) and knowledge log updated

https://claude.ai/code/session_019aFikmptPc91Fj4N2iDXQA

---

Generated by Claude Code

[cloudflare-workers-and-pages]

Deploying with    Cloudflare Workers

The latest updates on your project. Learn more about integrating Git with Workers.

Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	bashkit	9f3bf78	Commit Preview URL Branch Preview URL	Oct 07 2026, 05:57 PM