fix scm_to_latin1_stringn for substrings

* libguile/strings.c (scm_to_latin1_stringn): Fix for substrings.

* test-suite/standalone/Makefile.am:
* test-suite/standalone/test-scm-to-latin1-string.c: Add test case.

  Thanks to David Hansen for the bug report and test case, and Stefan
  Israelsson Tampe for the fix.

libguile/strings.c

@@ -1779,10 +1779,12 @@ scm_to_latin1_stringn (SCM str, size_t *lenp)
 
   if (scm_i_is_narrow_string (str))
     {
-      if (lenp)
-	*lenp = scm_i_string_length (str);
+      size_t len = scm_i_string_length (str);
 
-      result = scm_strdup (scm_i_string_data (str));
+      if (lenp)
+        *lenp = len;
+
+      result = scm_strndup (scm_i_string_data (str), len);
     }
   else
     result = scm_to_stringn (str, lenp, NULL,

test-suite/standalone/Makefile.am

@@ -178,6 +178,13 @@ test_scm_take_u8vector_LDADD = $(LIBGUILE_LDADD)
 check_PROGRAMS += test-scm-take-u8vector
 TESTS += test-scm-take-u8vector
 
+# test-scm-take-u8vector
+test_scm_to_latin1_string_SOURCES = test-scm-to-latin1-string.c
+test_scm_to_latin1_string_CFLAGS = ${test_cflags}
+test_scm_to_latin1_string_LDADD = $(LIBGUILE_LDADD)
+check_PROGRAMS += test-scm-to-latin1-string
+TESTS += test-scm-to-latin1-string
+
 if HAVE_SHARED_LIBRARIES
 
 # test-extensions

test-suite/standalone/test-scm-to-latin1-string.c

@@ -0,0 +1,78 @@
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <libguile.h>
+#include <stdlib.h>
+
+/*
+  This outputs:
+
+  dhansen@localhorst ~/tmp $ ./a.out
+  foo,bar
+  bar
+
+*/
+
+#define TEST(x) \
+  if (!(x)) abort()
+
+static void
+inner_main (void *data, int argc, char **argv)
+{
+  char *cstr;
+
+  SCM string, tokens, tok;
+
+  string = scm_from_latin1_string ("foo,bar");
+  tokens = scm_string_split (string, SCM_MAKE_CHAR (','));
+
+  TEST (scm_is_pair (tokens));
+  tok = scm_car (tokens);
+  TEST (scm_is_string (tok));
+  cstr = scm_to_latin1_string (tok);
+  TEST (strcmp (cstr, "foo") == 0);
+  free (cstr);
+  tokens = scm_cdr (tokens);
+  
+  TEST (scm_is_pair (tokens));
+  tok = scm_car (tokens);
+  TEST (scm_is_string (tok));
+  cstr = scm_to_latin1_string (tok);
+  TEST (strcmp (cstr, "bar") == 0);
+  free (cstr);
+  tokens = scm_cdr (tokens);
+  
+  TEST (scm_is_null (tokens));
+}
+
+int
+main (int argc, char **argv)
+{
+  scm_boot_guile (argc, argv, inner_main, NULL);
+
+  return EXIT_SUCCESS;
+}
+
+/* Local Variables: */
+/* compile-command: "gcc `pkg-config --cflags --libs guile-2.0` main.c" */
+/* End: */