bug#67064: [PATCH] Fix unread-string

Hello,

This patch simply fixes bug 67063.

Thanks,
Juli

* doc/ref/api-io.texi (Venerable Port Interfaces): Bring unread-string
procedure documentation in line with other procedures in the section.
* libguile/ports.c (scm_unread_string): Make port argument optional.
* test-suite/tests/ports.test: Test unread-char and unread-string
without ports.
---
 doc/ref/api-io.texi         | 3 +--
 libguile/ports.c            | 2 +-
 test-suite/tests/ports.test | 6 +++---
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/doc/ref/api-io.texi b/doc/ref/api-io.texi
index e263e2985..90411fbdf 100644
--- a/doc/ref/api-io.texi
+++ b/doc/ref/api-io.texi
@@ -1981,8 +1981,7 @@ The same as @code{unget-char}, except that @var{port} defaults to the
 current input port, and the arguments are swapped.  @xref{Textual I/O}.
 @end deffn
 
-@deffn {Scheme Procedure} unread-string str port
-@deffnx {C Function} scm_unread_string (str, port)
+@deffn {Scheme Procedure} unread-string str [port]
 The same as @code{unget-string}, except that @var{port} defaults to the
 current input port, and the arguments are swapped.  @xref{Textual I/O}.
 @end deffn
diff --git a/libguile/ports.c b/libguile/ports.c
index c25c20709..eb4a59bd5 100644
--- a/libguile/ports.c
+++ b/libguile/ports.c
@@ -2228,7 +2228,7 @@ SCM_DEFINE (scm_unread_char, "unread-char", 1, 1, 0,
 }
 #undef FUNC_NAME
 
-SCM_DEFINE (scm_unread_string, "unread-string", 2, 0, 0,
+SCM_DEFINE (scm_unread_string, "unread-string", 1, 1, 0,
             (SCM str, SCM port),
 	    "Place the string @var{str} in @var{port} so that its characters will be\n"
 	    "read in subsequent read operations.  If called multiple times, the\n"
diff --git a/test-suite/tests/ports.test b/test-suite/tests/ports.test
index 1b30e1a68..040bb02f0 100644
--- a/test-suite/tests/ports.test
+++ b/test-suite/tests/ports.test
@@ -590,13 +590,13 @@
 (with-input-from-string "walk on the moon\nmoon"
                         (lambda ()
                           (read-char)
-                          (unread-char #\a (current-input-port))
+                          (unread-char #\a)
                           (pass-if "unread-char"
                                    (char=? (read-char) #\a))
                           (read-line)
                           (let ((replacenoid "chicken enchilada"))
-                            (unread-char #\newline (current-input-port))
-                            (unread-string replacenoid (current-input-port))
+                            (unread-char #\newline)
+                            (unread-string replacenoid)
                             (pass-if "unread-string"
                                      (string=? (read-line) replacenoid)))
                           (pass-if "unread residue"
-- 
2.41.0