Fix breakage of SRFI-4 C accessors

* libguile/srfi-4.c (DEFINE_SRFI_4_C_FUNCS): Fix bad assumption that
  width was a byte width.  Thanks very much to Barry Fishman for the
  report, and to Daniel Llorens for tracking it down.

* test-suite/standalone/Makefile.am (test_srfi_4_CFLAGS):
* test-suite/standalone/test-srfi-4.c: Add test.

1 files changed, 87 insertions, 0 deletions

diff --git a/test-suite/standalone/test-srfi-4.c b/test-suite/standalone/test-srfi-4.c
new file mode 100644
index 000000000..22e079c1b
--- /dev/null
+++ b/test-suite/standalone/test-srfi-4.c
@@ -0,0 +1,87 @@
+/* Copyright (C) 2014 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 <stdio.h>
+#include <assert.h>
+
+static void
+test_writable_elements ()
+{
+  SCM elts = scm_list_4 (scm_from_int (1), scm_from_int (2),
+                         scm_from_int (3), scm_from_int (4));
+
+  {
+    SCM v = scm_u32vector (elts);
+    size_t len;
+    ssize_t inc;
+    scm_t_array_handle h;
+    scm_t_uint32 *elts = scm_u32vector_writable_elements (v, &h, &len, &inc);
+    assert (len == 4);
+    assert (inc == 1);
+    assert (elts[0] == 1);
+    assert (elts[3] == 4);
+    scm_array_handle_release (&h);
+  }
+
+  {
+    SCM v = scm_f32vector (elts);
+    size_t len;
+    ssize_t inc;
+    scm_t_array_handle h;
+    float *elts = scm_f32vector_writable_elements (v, &h, &len, &inc);
+    assert (len == 4);
+    assert (inc == 1);
+    assert (elts[0] == 1.0);
+    assert (elts[3] == 4.0);
+    scm_array_handle_release (&h);
+  }
+
+  {
+    SCM v = scm_c32vector (elts);
+    size_t len;
+    ssize_t inc;
+    scm_t_array_handle h;
+    float *elts = scm_c32vector_writable_elements (v, &h, &len, &inc);
+    assert (len == 4);
+    assert (inc == 1);
+    assert (elts[0] == 1.0);
+    assert (elts[1] == 0.0);
+    assert (elts[6] == 4.0);
+    assert (elts[7] == 0.0);
+    scm_array_handle_release (&h);
+  }
+}
+
+static void
+tests (void *data, int argc, char **argv)
+{
+  test_writable_elements ();
+}
+
+int
+main (int argc, char *argv[])
+{
+  scm_boot_guile (argc, argv, tests, NULL);
+  return 0;
+}