bindat (str, strz): Reject non-ASCII, non-`eight-bit' characters

* lisp/emacs-lisp/bindat.el (str) (strz): Signal an error if the user
attempts to pack a multibyte string containing characters other than
ASCII and `eight-bit' characters (bug#55897).
* doc/lispref/processes.texi (Bindat Types): Update documentation.
* test/lisp/emacs-lisp/bindat-tests.el (str) (strz): Add tests.

1 files changed, 16 insertions, 0 deletions

diff --git a/test/lisp/emacs-lisp/bindat-tests.el b/test/lisp/emacs-lisp/bindat-tests.el
index 1ce402977f5..8bb3baa485e 100644
--- a/test/lisp/emacs-lisp/bindat-tests.el
+++ b/test/lisp/emacs-lisp/bindat-tests.el
@@ -188,6 +188,22 @@
       (apply #'bindat-pack (append (car tc) (list prealloc)))
       (should (equal prealloc (cdr tc))))))
 
+(ert-deftest bindat-test--str-strz-multibyte ()
+  (dolist (spec (list (bindat-type str 2)
+                      (bindat-type strz 2)
+                      (bindat-type strz)))
+    (should (equal (bindat-pack spec (string-to-multibyte "x")) "x\0"))
+    (should (equal (bindat-pack spec (string-to-multibyte "\xff")) "\xff\0"))
+    (should-error (bindat-pack spec "💩"))
+    (should-error (bindat-pack spec "\N{U+ff}")))
+  (dolist (spec (list '((x str 2)) '((x strz 2))))
+    (should (equal (bindat-pack spec `((x . ,(string-to-multibyte "x"))))
+                   "x\0"))
+    (should (equal (bindat-pack spec `((x . ,(string-to-multibyte "\xff"))))
+                   "\xff\0"))
+    (should-error (bindat-pack spec '((x . "💩"))))
+    (should-error (bindat-pack spec '((x . "\N{U+ff}"))))))
+
 (let ((spec (bindat-type strz 2)))
   (ert-deftest bindat-test--strz-fixedlen-len ()
     (should (equal (bindat-length spec "") 2))