From 25f5045f9d0afc79aeab726542237ad3913dbded Mon Sep 17 00:00:00 2001
From: Mykhailo Chalyi <mike@chaliy.name>
Date: Fri, 27 Mar 2026 03:47:05 +0000
Subject: [PATCH] fix(parser): expand $'\n' ANSI-C quoting in concatenated
 function args

In read_continuation_into(), $'...' sequences were not recognized as
ANSI-C quoting. The $ was consumed as a word character and the following
'...' was treated as a regular single-quoted string, producing literal
$\n instead of a newline.

Add explicit $' detection in read_continuation_into() that delegates
to read_dollar_single_quoted_content() for proper escape expansion.

Closes #862
---
 crates/bashkit/src/parser/lexer.rs            | 13 +++++
 .../tests/spec_cases/bash/quote.test.sh       | 57 +++++++++++++++++++
 2 files changed, 70 insertions(+)

diff --git a/crates/bashkit/src/parser/lexer.rs b/crates/bashkit/src/parser/lexer.rs
index 57f9f6aa..bcaa6bb8 100644
--- a/crates/bashkit/src/parser/lexer.rs
+++ b/crates/bashkit/src/parser/lexer.rs
@@ -954,6 +954,19 @@ impl<'a> Lexer<'a> {
                         self.advance();
                     }
                 }
+                Some('$') => {
+                    // Check for $'...' ANSI-C quoting in continuation
+                    let mut lookahead = self.chars.clone();
+                    lookahead.next(); // skip $
+                    if lookahead.next() == Some('\'') {
+                        self.advance(); // consume $
+                        self.advance(); // consume opening '
+                        content.push_str(&self.read_dollar_single_quoted_content());
+                    } else {
+                        content.push('$');
+                        self.advance();
+                    }
+                }
                 Some(ch) if self.is_word_char(ch) => {
                     content.push(ch);
                     self.advance();
diff --git a/crates/bashkit/tests/spec_cases/bash/quote.test.sh b/crates/bashkit/tests/spec_cases/bash/quote.test.sh
index 67060f21..a28ce6d1 100644
--- a/crates/bashkit/tests/spec_cases/bash/quote.test.sh
+++ b/crates/bashkit/tests/spec_cases/bash/quote.test.sh
@@ -274,3 +274,60 @@ echo 'say "hi"'
 ### expect
 say "hi"
 ### end
+
+### quote_ansi_c_concat_func_arg
+# Issue #862: $'\n' concatenated in function argument position
+show() { printf '%q\n' "$1"; }
+show "a"$'\n'"b"
+### expect
+$'a\nb'
+### end
+
+### quote_ansi_c_tab_concat_func_arg
+# $'\t' concatenated in function argument position
+show() { printf '%q\n' "$1"; }
+show "a"$'\t'"b"
+### expect
+$'a\tb'
+### end
+
+### quote_ansi_c_sole_arg
+# $'\n' as sole function argument
+show() { printf '%q\n' "$1"; }
+show $'\n'
+### expect
+$'\n'
+### end
+
+### quote_ansi_c_at_start
+# $'\n' at start of concatenation
+show() { printf '%q\n' "$1"; }
+show $'\n'"after"
+### expect
+$'\nafter'
+### end
+
+### quote_ansi_c_at_end
+# $'\n' at end of concatenation
+show() { printf '%q\n' "$1"; }
+show "before"$'\n'
+### expect
+$'before\n'
+### end
+
+### quote_ansi_c_multiple_segments
+# Multiple ANSI-C segments concatenated
+show() { printf '%q\n' "$1"; }
+show "a"$'\n'"b"$'\t'"c"
+### expect
+$'a\nb\tc'
+### end
+
+### quote_ansi_c_via_variable_baseline
+# Baseline: ANSI-C via variable works
+show() { printf '%q\n' "$1"; }
+x="a"$'\n'"b"
+show "${x}"
+### expect
+$'a\nb'
+### end