master 5255fa452f 4/5: bindat (strz): Fix wrong-type-argument error when unpacking

[Stefan Monnier]

branch: master
commit 5255fa452f338c2ae97fa1ade70b396513bc6e9b
Author: Richard Hansen <rhansen@rhansen.org>
Commit: Stefan Monnier <monnier@iro.umontreal.ca>

    bindat (strz): Fix wrong-type-argument error when unpacking
    
    * lisp/emacs-lisp/bindat.el (strz): Fix (wrong-type-argument
    number-or-marker-p nil) error when unpacking a strz with
    unspecified (variable) length.
    * test/lisp/emacs-lisp/bindat-tests.el (strz): Mark test as passing.
---
 lisp/emacs-lisp/bindat.el            | 4 ++--
 test/lisp/emacs-lisp/bindat-tests.el | 1 -
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/lisp/emacs-lisp/bindat.el b/lisp/emacs-lisp/bindat.el
index e597dd6247..0725b677cf 100644
--- a/lisp/emacs-lisp/bindat.el
+++ b/lisp/emacs-lisp/bindat.el
@@ -165,12 +165,12 @@
     (if (stringp s) s
       (apply #'unibyte-string s))))
 
-(defun bindat--unpack-strz (len)
+(defun bindat--unpack-strz (&optional len)
   (let ((i 0) s)
     (while (and (if len (< i len) t) (/= (aref bindat-raw (+ bindat-idx i)) 0))
       (setq i (1+ i)))
     (setq s (substring bindat-raw bindat-idx (+ bindat-idx i)))
-    (setq bindat-idx (+ bindat-idx len))
+    (setq bindat-idx (+ bindat-idx (or len (1+ i))))
     (if (stringp s) s
       (apply #'unibyte-string s))))
 
diff --git a/test/lisp/emacs-lisp/bindat-tests.el 
b/test/lisp/emacs-lisp/bindat-tests.el
index cb7b6fe1c2..b3850f14f1 100644
--- a/test/lisp/emacs-lisp/bindat-tests.el
+++ b/test/lisp/emacs-lisp/bindat-tests.el
@@ -199,7 +199,6 @@
     (should (equal (bindat-pack spec "abc") "abc\0")))
 
   (ert-deftest bindat-test--strz-varlen-unpack ()
-    :expected-result :failed
     ;; There is no test for unpacking a string without a null
     ;; terminator because such packed strings cannot be produced from
     ;; the spec (packing "a" should produce "a\0", not "a").