fix(php-shim): emit NUL bytes as concatenation in var_export

PHP var_export breaks NUL bytes out of single-quoted string literals as
`' . "\0" . '` because a raw NUL byte is invalid in PHP source. The
shim embedded the raw byte instead, diverging from Composer's generated
installed.php (where references can contain NUL).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/crates/shirabe-php-shim/src/var.rs b/crates/shirabe-php-shim/src/var.rs
index 3fba9d6..f0e55d5 100644
--- a/crates/shirabe-php-shim/src/var.rs
+++ b/crates/shirabe-php-shim/src/var.rs
@@ -443,6 +443,11 @@ fn var_export_string(s: &str) -> String {
     let mut out = String::with_capacity(s.len() + 2);
     out.push('\'');
     for c in s.chars() {
+        // PHP var_export breaks NUL bytes out of the single-quoted literal as `' . "\0" . '`.
+        if c == '\0' {
+            out.push_str("' . \"\\0\" . '");
+            continue;
+        }
         if c == '\'' || c == '\\' {
             out.push('\\');
         }