feat(php-src): add a BSD-licensed crate for php-src derived code

The audit in .ken/php-shim-copying.md judged 14 functions in
shirabe-php-shim (plus php_wordwrap in shirabe-external-packages) to be
line-by-line transcriptions or structural imitations of php-src. PHP's
relicensing to 3-clause BSD makes keeping them legal, but the boundary
between BSD-derived and MIT code was invisible in the source tree.

Moving them into their own crate puts the license into the build
metadata (so NOTICE generation follows the binary), makes a reverse
dependency a compile error, and encodes the origin in the module path,
which mirrors php-src's ext tree. Each function records its origin in a
fixed-format doc comment, and a new php_src_derivation_boundary linter
fails if `php-src` appears in any Rust source outside the crate.

Public paths under shirabe_php_shim:: are unchanged: functions that are
themselves derived are re-exported with `pub use`, and the wrappers that
only validate arguments stay on the MIT side.

This also resolves the duplicate wordwrap implementation.
shirabe_php_shim::wordwrap was todo!(), so SymfonyStyle::block panicked,
while shirabe-external-packages carried its own copy. Both now go
through the single port, verified against real PHP on 13 cases covering
multi-character breaks and cut.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 1 insertions, 38 deletions

diff --git a/crates/shirabe-php-shim/src/process.rs b/crates/shirabe-php-shim/src/process.rs
index 4615ff91..57d9b35a 100644
--- a/crates/shirabe-php-shim/src/process.rs
+++ b/crates/shirabe-php-shim/src/process.rs
@@ -1,5 +1,6 @@
 use crate::{ChildPipe, PhpMixed, PhpResource, StreamBacking, StreamState};
 use indexmap::IndexMap;
+pub use shirabe_php_src::standard::exec::escapeshellcmd;
 
 pub const SIGINT: i64 = 2;
 pub const SIGTERM: i64 = 15;
@@ -77,44 +78,6 @@ pub fn system(command: &str, result_code: Option<&mut i64>) -> Option<String> {
     Some(lines.last().cloned().unwrap_or_default())
 }
 
-// Port of PHP's escapeshellcmd (Unix branch). Shell metacharacters are backslash-escaped; quote
-// characters are escaped only when unpaired, paired quotes being left intact.
-pub fn escapeshellcmd(command: &str) -> String {
-    let bytes = command.as_bytes();
-    let len = bytes.len();
-    let mut out: Vec<u8> = Vec::with_capacity(len);
-    // Byte index of the matching closing quote while inside a paired quote run.
-    let mut paired: Option<usize> = None;
-    let mut x = 0;
-    while x < len {
-        let c = bytes[x];
-        match c {
-            b'"' | b'\'' => {
-                if paired.is_none() {
-                    if let Some(rel) = bytes[x + 1..].iter().position(|&b| b == c) {
-                        paired = Some(x + 1 + rel);
-                    } else {
-                        out.push(b'\\');
-                    }
-                } else if paired == Some(x) {
-                    paired = None;
-                } else {
-                    out.push(b'\\');
-                }
-                out.push(c);
-            }
-            b'#' | b'&' | b';' | b'`' | b'|' | b'*' | b'?' | b'~' | b'<' | b'>' | b'^' | b'('
-            | b')' | b'[' | b']' | b'{' | b'}' | b'$' | b'\\' | 0x0A | 0xFF => {
-                out.push(b'\\');
-                out.push(c);
-            }
-            _ => out.push(c),
-        }
-        x += 1;
-    }
-    String::from_utf8_lossy(&out).into_owned()
-}
-
 // Unix branch of PHP's escapeshellarg: wrap in single quotes, escaping embedded single quotes.
 pub fn escapeshellarg(arg: &str) -> String {
     let mut out = String::with_capacity(arg.len() + 2);