* Makefile.am (check_PROGRAMS): add check_mb.

(check_mb_SOURCES, check_mb_LDADD): New variables.
(check-local): Run check_mb.
* check_mb.c: New file, testing multibyte processing functions.
* mb.c (scm_mb_get_func): Fix typo in variable name.
(scm_mb_walk): Fix another typo in variable name.
(scm_mb_multibyte_to_fixed): Use the right variable for the end
of the multibyte text.
(scm_mb_fixed_to_multibyte): Use the return value from scm_mb_put,
instead of making a separate call to scm_mb_len.

5 files changed, 364 insertions, 29 deletions

diff --git a/libguile/Makefile.am b/libguile/Makefile.am
index 364a9c76f..dda9508d6 100644
--- a/libguile/Makefile.am
+++ b/libguile/Makefile.am
@@ -105,15 +105,18 @@ modinclude_DATA = scmconfig.h
 bin_SCRIPTS = guile-snarf
 
 check_ldadd = libguile.la ${THREAD_LIBS_LOCAL}
-check_PROGRAMS = gh_test_c gh_test_repl
+check_PROGRAMS = gh_test_c gh_test_repl check_mb
 gh_test_c_SOURCES = gh_test_c.c
 gh_test_c_LDADD = ${check_ldadd}
 gh_test_repl_SOURCES = gh_test_repl.c
 gh_test_repl_LDADD = ${check_ldadd}
+check_mb_SOURCES = check_mb.c
+check_mb_LDADD = ${check_ldadd}
 
 check-local:
 	echo '(+ 1 2 3)' | GUILE_LOAD_PATH=${top_srcdir}:.. ./gh_test_c; echo
 	echo '(+ 1 2 3)' | GUILE_LOAD_PATH=${top_srcdir}:.. ./gh_test_repl; echo
+	GUILE_LOAD_PATH=${top_srcdir}:.. ./check_mb
 
 EXTRA_DIST = ChangeLog-gh ChangeLog-scm ChangeLog-threads dynl-dl.c \
     dynl-dld.c dynl-shl.c dynl-vms.c DYNAMIC-LINKING cpp_signal.c cpp_errno.c \
diff --git a/libguile/Makefile.in b/libguile/Makefile.in
index 6d4445cc4..a2e42006f 100644
--- a/libguile/Makefile.in
+++ b/libguile/Makefile.in
@@ -103,10 +103,10 @@ bin_PROGRAMS = guile
 guile_SOURCES = guile.c
 guile_LDADD = libguile.la ${THREAD_LIBS_LOCAL}
 
-libguile_la_SOURCES =      alist.c arbiters.c async.c backtrace.c boolean.c chars.c		    continuations.c debug.c dynl.c dynwind.c eq.c error.c eval.c	    evalext.c feature.c filesys.c fluids.c fports.c gc.c gdbint.c	    gh_data.c gh_eval.c gh_funcs.c gh_init.c gh_io.c gh_list.c		    gh_predicates.c gsubr.c guardians.c hash.c hashtab.c init.c		    ioext.c keywords.c lang.c list.c load.c macros.c mallocs.c		    modules.c net_db.c numbers.c objects.c objprop.c options.c pairs.c	    ports.c posix.c print.c procprop.c procs.c ramap.c random.c read.c	    root.c scmsigs.c script.c simpos.c smob.c socket.c sort.c		    srcprop.c stackchk.c stacks.c stime.c strings.c strop.c strorder.c	    strports.c struct.c symbols.c tag.c throw.c unif.c variable.c	    vectors.c version.c vports.c weaks.c
+libguile_la_SOURCES =      alist.c arbiters.c async.c backtrace.c boolean.c chars.c		    continuations.c debug.c dynl.c dynwind.c eq.c error.c eval.c	    evalext.c feature.c filesys.c fluids.c fports.c gc.c gdbint.c	    gh_data.c gh_eval.c gh_funcs.c gh_init.c gh_io.c gh_list.c		    gh_predicates.c gsubr.c guardians.c hash.c hashtab.c init.c		    ioext.c keywords.c lang.c list.c load.c macros.c mallocs.c mb.c	    modules.c net_db.c numbers.c objects.c objprop.c options.c pairs.c	    ports.c posix.c print.c procprop.c procs.c ramap.c random.c read.c	    root.c scmsigs.c script.c simpos.c smob.c socket.c sort.c		    srcprop.c stackchk.c stacks.c stime.c strings.c strop.c strorder.c	    strports.c struct.c symbols.c tag.c throw.c unif.c variable.c	    vectors.c version.c vports.c weaks.c
 
 
-BUILT_SOURCES =      cpp_err_symbols.c cpp_sig_symbols.c libpath.h alist.x arbiters.x	    async.x backtrace.x boolean.x chars.x continuations.x debug.x	    dynl.x dynwind.x eq.x error.x eval.x evalext.x feature.x filesys.x	    fluids.x fports.x gc.x gsubr.x					    guardians.x hash.x hashtab.x init.x ioext.x iselect.x keywords.x	    lang.x list.x load.x macros.x mallocs.x modules.x net_db.x		    numbers.x objects.x objprop.x options.x pairs.x ports.x posix.x	    print.x procprop.x procs.x random.x ramap.x read.x regex-posix.x	    root.x scmsigs.x script.x simpos.x smob.x socket.x sort.x		    srcprop.x stackchk.x stacks.x stime.x strings.x strop.x strorder.x	    strports.x struct.x symbols.x tag.x threads.x throw.x unif.x	    variable.x vectors.x version.x vports.x weaks.x
+BUILT_SOURCES =      cpp_err_symbols.c cpp_sig_symbols.c libpath.h alist.x arbiters.x	    async.x backtrace.x boolean.x chars.x continuations.x debug.x	    dynl.x dynwind.x eq.x error.x eval.x evalext.x feature.x filesys.x	    fluids.x fports.x gc.x gsubr.x guardians.x hash.x hashtab.x init.x	    ioext.x iselect.x keywords.x lang.x list.x load.x macros.x		    mallocs.x mb.x modules.x net_db.x numbers.x objects.x objprop.x	    options.x pairs.x ports.x posix.x print.x procprop.x procs.x	    random.x ramap.x read.x regex-posix.x root.x scmsigs.x script.x	    simpos.x smob.x socket.x sort.x srcprop.x stackchk.x stacks.x	    stime.x strings.x strop.x strorder.x strports.x struct.x symbols.x	    tag.x threads.x throw.x unif.x variable.x vectors.x version.x	    vports.x weaks.x
 
 
 EXTRA_libguile_la_SOURCES = _scm.h     strerror.c inet_aton.c putenv.c     threads.c alloca.c     regex-posix.c iselect.c
@@ -125,7 +125,7 @@ pkginclude_HEADERS = gh.h
 
 # These are headers visible as <libguile/mumble.h>.
 modincludedir = $(includedir)/libguile
-modinclude_HEADERS =      __scm.h alist.h arbiters.h async.h backtrace.h boolean.h chars.h	    continuations.h debug.h dynl.h dynwind.h eq.h error.h eval.h	    evalext.h feature.h filesys.h fports.h gc.h gdb_interface.h		    gdbint.h genio.h gsubr.h guardians.h hash.h hashtab.h init.h	    ioext.h keywords.h kw.h lang.h list.h load.h macros.h mallocs.h 	    modules.h net_db.h numbers.h objects.h objprop.h options.h pairs.h	    ports.h posix.h regex-posix.h print.h procprop.h procs.h random.h	    ramap.h read.h root.h scmsigs.h script.h simpos.h smob.h socket.h	    sort.h srcprop.h stackchk.h stacks.h stime.h strings.h strop.h	    strorder.h strports.h struct.h symbols.h tag.h tags.h throw.h	    unif.h variable.h vectors.h version.h vports.h weaks.h snarf.h	    threads.h coop-defs.h fluids.h iselect.h
+modinclude_HEADERS =      __scm.h alist.h arbiters.h async.h backtrace.h boolean.h chars.h	    continuations.h debug.h dynl.h dynwind.h eq.h error.h eval.h	    evalext.h feature.h filesys.h fports.h gc.h gdb_interface.h		    gdbint.h genio.h gsubr.h guardians.h hash.h hashtab.h init.h	    ioext.h keywords.h kw.h lang.h list.h load.h macros.h mallocs.h	    mb.h modules.h net_db.h numbers.h objects.h objprop.h options.h	    pairs.h ports.h posix.h regex-posix.h print.h procprop.h procs.h	    random.h ramap.h read.h root.h scmsigs.h script.h simpos.h smob.h	    socket.h sort.h srcprop.h stackchk.h stacks.h stime.h strings.h	    strop.h strorder.h strports.h struct.h symbols.h tag.h tags.h	    throw.h unif.h variable.h vectors.h version.h vports.h weaks.h	    snarf.h threads.h coop-defs.h fluids.h iselect.h
 
 
 modinclude_DATA = scmconfig.h
@@ -133,11 +133,13 @@ modinclude_DATA = scmconfig.h
 bin_SCRIPTS = guile-snarf
 
 check_ldadd = libguile.la ${THREAD_LIBS_LOCAL}
-check_PROGRAMS = gh_test_c gh_test_repl
+check_PROGRAMS = gh_test_c gh_test_repl check_mb
 gh_test_c_SOURCES = gh_test_c.c
 gh_test_c_LDADD = ${check_ldadd}
 gh_test_repl_SOURCES = gh_test_repl.c
 gh_test_repl_LDADD = ${check_ldadd}
+check_mb_SOURCES = check_mb.c
+check_mb_LDADD = ${check_ldadd}
 
 EXTRA_DIST = ChangeLog-gh ChangeLog-scm ChangeLog-threads dynl-dl.c     dynl-dld.c dynl-shl.c dynl-vms.c DYNAMIC-LINKING cpp_signal.c cpp_errno.c     cpp_err_symbols.in cpp_sig_symbols.in cpp_cnvt.awk coop-threads.h.cygnus     coop-threads.c.cygnus mit-pthreads.h mit-pthreads.c fsu-pthreads.h
 
@@ -168,7 +170,7 @@ error.lo eval.lo evalext.lo feature.lo filesys.lo fluids.lo fports.lo \
 gc.lo gdbint.lo gh_data.lo gh_eval.lo gh_funcs.lo gh_init.lo gh_io.lo \
 gh_list.lo gh_predicates.lo gsubr.lo guardians.lo hash.lo hashtab.lo \
 init.lo ioext.lo keywords.lo lang.lo list.lo load.lo macros.lo \
-mallocs.lo modules.lo net_db.lo numbers.lo objects.lo objprop.lo \
+mallocs.lo mb.lo modules.lo net_db.lo numbers.lo objects.lo objprop.lo \
 options.lo pairs.lo ports.lo posix.lo print.lo procprop.lo procs.lo \
 ramap.lo random.lo read.lo root.lo scmsigs.lo script.lo simpos.lo \
 smob.lo socket.lo sort.lo srcprop.lo stackchk.lo stacks.lo stime.lo \
@@ -185,6 +187,9 @@ gh_test_c_LDFLAGS =
 gh_test_repl_OBJECTS =  gh_test_repl.o
 gh_test_repl_DEPENDENCIES =  libguile.la
 gh_test_repl_LDFLAGS = 
+check_mb_OBJECTS =  check_mb.o
+check_mb_DEPENDENCIES =  libguile.la
+check_mb_LDFLAGS = 
 SCRIPTS =  $(bin_SCRIPTS)
 
 CFLAGS = @CFLAGS@
@@ -206,17 +211,17 @@ DISTFILES = $(DIST_COMMON) $(SOURCES) $(HEADERS) $(TEXINFOS) $(EXTRA_DIST)
 TAR = tar
 GZIP_ENV = --best
 DEP_FILES =  .deps/alist.P .deps/alloca.P .deps/arbiters.P .deps/async.P \
-.deps/backtrace.P .deps/boolean.P .deps/chars.P .deps/continuations.P \
-.deps/cpp_err_symbols.P .deps/cpp_sig_symbols.P .deps/debug.P \
-.deps/dynl.P .deps/dynwind.P .deps/eq.P .deps/error.P .deps/eval.P \
-.deps/evalext.P .deps/feature.P .deps/filesys.P .deps/fluids.P \
-.deps/fports.P .deps/gc.P .deps/gdbint.P .deps/gh_data.P \
+.deps/backtrace.P .deps/boolean.P .deps/chars.P .deps/check_mb.P \
+.deps/continuations.P .deps/cpp_err_symbols.P .deps/cpp_sig_symbols.P \
+.deps/debug.P .deps/dynl.P .deps/dynwind.P .deps/eq.P .deps/error.P \
+.deps/eval.P .deps/evalext.P .deps/feature.P .deps/filesys.P \
+.deps/fluids.P .deps/fports.P .deps/gc.P .deps/gdbint.P .deps/gh_data.P \
 .deps/gh_eval.P .deps/gh_funcs.P .deps/gh_init.P .deps/gh_io.P \
 .deps/gh_list.P .deps/gh_predicates.P .deps/gh_test_c.P \
 .deps/gh_test_repl.P .deps/gsubr.P .deps/guardians.P .deps/guile.P \
 .deps/hash.P .deps/hashtab.P .deps/inet_aton.P .deps/init.P \
 .deps/ioext.P .deps/iselect.P .deps/keywords.P .deps/lang.P \
-.deps/list.P .deps/load.P .deps/macros.P .deps/mallocs.P \
+.deps/list.P .deps/load.P .deps/macros.P .deps/mallocs.P .deps/mb.P \
 .deps/modules.P .deps/net_db.P .deps/numbers.P .deps/objects.P \
 .deps/objprop.P .deps/options.P .deps/pairs.P .deps/ports.P \
 .deps/posix.P .deps/print.P .deps/procprop.P .deps/procs.P \
@@ -228,8 +233,8 @@ DEP_FILES =  .deps/alist.P .deps/alloca.P .deps/arbiters.P .deps/async.P \
 .deps/struct.P .deps/symbols.P .deps/tag.P .deps/threads.P \
 .deps/throw.P .deps/unif.P .deps/variable.P .deps/vectors.P \
 .deps/version.P .deps/vports.P .deps/weaks.P
-SOURCES = $(libguile_la_SOURCES) $(EXTRA_libguile_la_SOURCES) $(guile_SOURCES) $(gh_test_c_SOURCES) $(gh_test_repl_SOURCES)
-OBJECTS = $(libguile_la_OBJECTS) $(guile_OBJECTS) $(gh_test_c_OBJECTS) $(gh_test_repl_OBJECTS)
+SOURCES = $(libguile_la_SOURCES) $(EXTRA_libguile_la_SOURCES) $(guile_SOURCES) $(gh_test_c_SOURCES) $(gh_test_repl_SOURCES) $(check_mb_SOURCES)
+OBJECTS = $(libguile_la_OBJECTS) $(guile_OBJECTS) $(gh_test_c_OBJECTS) $(gh_test_repl_OBJECTS) $(check_mb_OBJECTS)
 
 all: all-redirect
 .SUFFIXES:
@@ -380,6 +385,10 @@ gh_test_repl: $(gh_test_repl_OBJECTS) $(gh_test_repl_DEPENDENCIES)
 	@rm -f gh_test_repl
 	$(LINK) $(gh_test_repl_LDFLAGS) $(gh_test_repl_OBJECTS) $(gh_test_repl_LDADD) $(LIBS)
 
+check_mb: $(check_mb_OBJECTS) $(check_mb_DEPENDENCIES)
+	@rm -f check_mb
+	$(LINK) $(check_mb_LDFLAGS) $(check_mb_OBJECTS) $(check_mb_LDADD) $(LIBS)
+
 install-binSCRIPTS: $(bin_SCRIPTS)
 	@$(NORMAL_INSTALL)
 	$(mkinstalldirs) $(DESTDIR)$(bindir)
@@ -658,6 +667,7 @@ maintainer-clean-generic clean mostlyclean distclean maintainer-clean
 check-local:
 	echo '(+ 1 2 3)' | GUILE_LOAD_PATH=${top_srcdir}:.. ./gh_test_c; echo
 	echo '(+ 1 2 3)' | GUILE_LOAD_PATH=${top_srcdir}:.. ./gh_test_repl; echo
+	GUILE_LOAD_PATH=${top_srcdir}:.. ./check_mb
 
 libpath.h: $(srcdir)/Makefile.in  $(top_builddir)/config.status
 	@echo "Generating libpath.h..." 
diff --git a/libguile/check_mb.c b/libguile/check_mb.c
new file mode 100644
index 000000000..2131cecb2
--- /dev/null
+++ b/libguile/check_mb.c
@@ -0,0 +1,324 @@
+/*	Copyright (C) 1999 Free Software Foundation, Inc.
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ * 
+ * This program 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 General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307 USA
+ *
+ * As a special exception, the Free Software Foundation gives permission
+ * for additional uses of the text contained in its release of GUILE.
+ *
+ * The exception is that, if you link the GUILE library with other files
+ * to produce an executable, this does not by itself cause the
+ * resulting executable to be covered by the GNU General Public License.
+ * Your use of that executable is in no way restricted on account of
+ * linking the GUILE library code into it.
+ *
+ * This exception does not however invalidate any other reasons why
+ * the executable file might be covered by the GNU General Public License.
+ *
+ * This exception applies only to the code released by the
+ * Free Software Foundation under the name GUILE.  If you copy
+ * code from other Free Software Foundation releases into a copy of
+ * GUILE, as the General Public License permits, the exception does
+ * not apply to the code that you add in this way.  To avoid misleading
+ * anyone as to the status of such modified files, you must delete
+ * this exception notice from them.
+ *
+ * If you write modifications of your own for GUILE, it is your choice
+ * whether to permit this exception to apply to your modifications.
+ * If you do not wish that, delete this exception notice.
+ */
+
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <gh.h>
+
+struct pair {
+  scm_char_t character;
+  unsigned char encoding[10];
+  int encoding_length; 
+};
+
+struct pair pairs[] = {
+
+  /* Check some ASCII characters.  */
+  { 0,   { 0 },   1 },
+  { 127, { 127 }, 1 },
+  { 31,  { 31 },  1 },
+  { 32,  { 32 },  1 },
+  { 42,  { 42 },  1 },
+
+  /* Sometimes we mark something as an "end of range", when it's not
+     actually the last character that would use that encoding form.
+     This is because not all character set numbers are assigned, and we
+     can't use unassigned character set numbers.  So the value given is
+     the last value which actually corresponds to something in a real
+     character set.  */
+
+  /* Check some characters encoded in two bytes.  */
+  { 2208, { 0x81, 0xA0 }, 2 }, /* beginning of range */
+  { 3839, { 0x8d, 0xFF }, 2 }, /* end of range */
+  { 2273, { 0x81, 0xE1 }, 2 },
+
+  /* Check some big characters encoded in three bytes.  */
+  { 20512,  { 0x90, 0xA0, 0xA0 }, 3 }, /* beginning of range */
+  { 180223, { 0x99, 0xFF, 0xFF }, 3 }, /* end of range */
+  { 53931,  { 0x92, 0xA5, 0xAB }, 3 },
+
+  /* Check some small characters encoded in three bytes --- some from
+     the 0x9A prefix range, and some from the 0x9B prefix range.  */
+  { 6176,   { 0x9A, 0xA0, 0xA0 }, 3 },  /* start of the #9A prefix range */
+  { 7167,   { 0x9A, 0xA7, 0xFF }, 3 },  /* end   of the #9A prefix range */
+  { 14368,  { 0x9B, 0xE0, 0xA0 }, 3 },  /* start of the #9B prefix range */
+  { 14591,  { 0x9B, 0xE1, 0xFF }, 3 },  /* end   of the #9B prefix range */
+
+  /* Check some characters encoded in four bytes.  */
+  { 266272, { 0x9C, 0xF0, 0xA0, 0xA0 }, 4 },/* start of the #9C prefix range */
+  { 294911, { 0x9C, 0xF1, 0xFF, 0xFF }, 4 },/* end   of the #9C prefix range */
+  { 348192, { 0x9D, 0xF5, 0xA0, 0xA0 }, 4 },/* start of the #9D prefix range */
+  { 475135, { 0x9D, 0xFC, 0xFF, 0xFF }, 4 },/* start of the #9D prefix range */
+
+  { 0, { 0 }, 0 }
+};
+
+#define NUM_PAIRS ((sizeof (pairs) / sizeof (pairs[0])) - 1)
+
+
+static void
+test_one_char_encodings ()
+{
+  struct pair *p;
+
+  for (p = pairs; p->encoding_length > 0; p++)
+    {
+      unsigned char buffer[scm_mb_max_len + 10];
+      int i;
+      int len;
+
+      /* scm_mb_len_char should return a sane value.  */
+      len = scm_mb_len_char (p->character);
+      if (len <= 0 || len > scm_mb_max_len)
+	exit (1);
+      if (len != p->encoding_length)
+	exit (1);
+
+      /* scm_mb_put should return the same length, and write that many
+         characters, but no more.  */
+      memset (buffer, 1, sizeof (buffer));
+      if (scm_mb_put (p->character, buffer) != len)
+	exit (1);
+      for (i = 0; i < len; i++)
+	if (buffer[i] == 1)
+	  exit (1);
+      for (; i < sizeof (buffer); i++)
+	if (buffer[i] != 1)
+	  exit (1);
+
+      /* Compare the encoding against the one in our table.  */
+      if (memcmp (buffer, p->encoding, len))
+	exit (1);
+
+      /* Try to get the character, and see if it works.  */
+      if (scm_mb_get (buffer) != p->character)
+	exit (1);
+
+      /* Check against value returned by scm_mb_len.  */
+      if (scm_mb_len (buffer[0]) != len)
+	exit (1);
+
+      /* Test ceiling and floor functions.  */
+      for (i = 0; i < len; i++)
+	if (scm_mb_floor (buffer + i) != buffer)
+	  exit (1);
+      for (i = 1; i < len; i++)
+	if (scm_mb_ceiling (buffer + i) != buffer + len)
+	  exit (1);
+    }
+}
+
+
+/* Fill BUFFER with LEN random numbers in the range 0 to MODULUS - 1.
+   Use SEED to choose the random numbers.  */
+static void
+make_permutation (int modulus, int len, int *buffer, unsigned int seed)
+{
+  int i;
+
+  srandom (seed);
+  for (i = 0; i < len; i++)
+    buffer[i] = (unsigned long) random () % modulus;
+
+  if (len > 0)
+    buffer[(unsigned long) random % len] = seed % modulus;
+}
+
+#define MAX_STRING_LEN 20
+static void
+test_string_encodings ()
+{
+  int perm[MAX_STRING_LEN];
+  unsigned char buffer[scm_mb_max_len * MAX_STRING_LEN];
+  int start[MAX_STRING_LEN];
+  unsigned int seed;
+  int len;
+
+  for (seed = 0; seed < 100; seed++)
+    for (len = 0; len < MAX_STRING_LEN; len++)
+      {
+	int i;
+	int bytes;
+	struct pair *p;
+	unsigned char *t;
+
+	/* Choose a random sequence of characters to try out.  */
+	make_permutation (NUM_PAIRS, len, perm, seed);
+	
+	/* Render those characters into the buffer.  */
+ 	t = buffer;
+	bytes = 0;
+	for (i = 0; i < len; i++)
+	  {
+	    start[i] = t - buffer;
+	    p = &pairs[perm[i]];
+	    t += scm_mb_put (p->character, t);
+	    bytes += p->encoding_length;
+	  }
+	if (t != buffer + bytes)
+	  exit (1);
+
+	/* Check its length.  */
+	if (scm_mb_count (buffer, bytes) != len)
+	  exit (1);
+
+	/* Read it back using the offsets we recorded.  */
+	for (i = 0; i < len; i++)
+	  {
+	    if (! scm_mb_boundary_p (buffer + start[i]))
+	      exit (1);
+	    if (scm_mb_get (buffer + start[i]) != pairs[perm[i]].character)
+	      exit (1);
+	  }
+
+	/* Read it back using scm_mb_walk.  */
+	t = buffer;
+	for (i = 0; i < len; i++)
+	  {
+	    if (scm_mb_walk ((const unsigned char **)&t) != pairs[perm[i]].character)
+	      exit (1);
+	    if (t > buffer + bytes)
+	      exit (1);
+	  }
+	if (t != buffer + bytes)
+	  exit (1);
+
+	/* Try going forward and backward for each character.  */
+	for (i = 0; i < len - 1; i++)
+	  {
+	    if (scm_mb_prev (buffer + start[i + 1]) != buffer + start[i])
+	      exit (1);
+	    if (scm_mb_next (buffer + start[i]) != buffer + start[i + 1])
+	      exit (1);
+	  }
+
+	/* Try fetching characters out of the middle, without caching.  */
+	for (i = 0; i < len; i++)
+	  if (scm_mb_index (buffer, bytes, i) != buffer + start[i])
+	    exit (1);
+
+	/* Try fetching characters out of the middle, with caching.  */
+	{
+	  struct scm_mb_cache cache;
+
+	  cache.character = 0;
+	  cache.byte = 0;
+
+	  /* scan forwards */
+	  for (i = 0; i < len; i++)
+	    if (scm_mb_index_cached (buffer, bytes, i, &cache)
+		!= buffer + start[i])
+	      exit (1);
+
+	  /* scan backwards */
+	  for (i = len - 1; i >= 0; i--)
+	    if (scm_mb_index_cached (buffer, bytes, i, &cache)
+		!= buffer + start[i])
+	      exit (1);
+
+	  /* Try fetching characters in random order, with caching.  */
+	  {
+	    int index[MAX_STRING_LEN];
+
+	    for (i = 0; i < len; i++)
+	      index[i] = i;
+
+	    srandom (seed + len + 1);
+	    for (i = 0; i < len; i++)
+	      {
+		int j, temp;
+		j = (unsigned long) random () % len;
+		temp = index[i];
+		index[i] = index[j];
+		index[j] = temp;
+	      }
+
+	    for (i = 0; i < len; i++)
+	      if (scm_mb_index_cached (buffer, bytes, index[i], &cache)
+		  != buffer + start[index[i]])
+		exit (1);
+	  }
+	}
+
+	/* Try converting whole strings back and forth.  */
+	{
+	  int result_len;
+	  scm_char_t *copy = scm_mb_multibyte_to_fixed (buffer, bytes,
+							&result_len);
+	  unsigned char *copy2;
+
+	  if (result_len != len)
+	    exit (1);
+	  for (i = 0; i < len; i++)
+	    if (copy[i] != pairs[perm[i]].character)
+	      exit (1);
+
+	  copy2 = scm_mb_fixed_to_multibyte (copy, len, &result_len);
+	  if (result_len != bytes)
+	    exit (1);
+	  if (memcmp (copy2, buffer, bytes))
+	    exit (1);
+	  if (copy2[bytes] != '\0')
+	    exit (1);
+
+	  free (copy);
+	  free (copy2);
+	}
+      }
+}
+
+static void 
+main_prog (int argc, char *argv[])
+{
+  test_one_char_encodings ();
+  test_string_encodings ();
+}
+
+int 
+main (int argc, char *argv[])
+{
+  gh_enter (argc, argv, main_prog);
+  return 0;
+}
+
diff --git a/libguile/mb.c b/libguile/mb.c
index 10c5b19e1..d7c9574ba 100644
--- a/libguile/mb.c
+++ b/libguile/mb.c
@@ -244,7 +244,7 @@ scm_mb_get_func (const unsigned char *p)
     }
   else if (lead < 0x9A)
     {
-      unsigned char set = load;
+      unsigned char set = lead;
       unsigned char pos_hi = p[1] & 0x7f;
       unsigned char pos_lo = p[2] & 0x7f;
 
@@ -417,7 +417,7 @@ scm_mb_count (const unsigned char *p, int len)
 scm_char_t
 scm_mb_walk (const unsigned char **pp)
 {
-  const unsigned char *p = *p;
+  const unsigned char *p = *pp;
   scm_char_t c = scm_mb_get (p);
   *pp = p + scm_mb_len (*p);
   return c;
@@ -540,7 +540,7 @@ scm_mb_multibyte_to_fixed (const unsigned char *p, int len, int *result_len)
   buf = scm_must_malloc (len * sizeof (*buf), "scm_mb_multibyte_to_fixed");
   buf_len = 0;
 
-  while (p < len)
+  while (p < end)
     {
       scm_char_t c = scm_mb_get (p);
       if (c < 0)
@@ -574,10 +574,7 @@ scm_mb_fixed_to_multibyte (const scm_char_t *fixed, int len, int *result_len)
   buf = scm_must_malloc (buf_size + 1, "scm_mb_fixed_to_multibyte");
   p = buf;
   for (i = 0; i < len; i++)
-    {
-      scm_mb_put (fixed[i], p);
-      p += scm_mb_len (*p);
-    }
+    p += scm_mb_put (fixed[i], p);
 
   /* Was the size we computed actually correct?  */
   if (p != buf + buf_size)
diff --git a/libguile/mb.h b/libguile/mb.h
index 725c5661d..4ef94dc91 100644
--- a/libguile/mb.h
+++ b/libguile/mb.h
@@ -98,8 +98,8 @@ extern int scm_mb_len_char_func (scm_char_t c);
 #define scm_mb_boundary_p(p) (*(p) < 0xA0)
 
 /* Round P to the previous/next character boundary.  */
-extern unsigned char *scm_mb_floor (const unsigned char *p);
-extern unsigned char *scm_mb_ceiling (const unsigned char *p);
+extern const unsigned char *scm_mb_floor (const unsigned char *p);
+extern const unsigned char *scm_mb_ceiling (const unsigned char *p);
 
 
 /* Multibyte string functions.  */
@@ -111,13 +111,14 @@ extern int scm_mb_count (const unsigned char *p, int len);
 extern scm_char_t scm_mb_walk (const unsigned char **pp);
 
 /* Return the address of the character before P.  */
-extern unsigned char *scm_mb_prev (const unsigned char *p);
+extern const unsigned char *scm_mb_prev (const unsigned char *p);
 
 /* Return the address of the character after P.  */
-extern unsigned char *scm_mb_next (const unsigned char *p);
+extern const unsigned char *scm_mb_next (const unsigned char *p);
 
 /* Return the location of the I'th character in LEN bytes at P.  */
-extern unsigned char *scm_mb_index (const unsigned char *p, int len, int i);
+extern const unsigned char *scm_mb_index (const unsigned char *p, int len,
+					  int i);
 
 /* A cache of information about the positions of characters in
    strings.  Initialize all elements to zero before using.  */
@@ -132,9 +133,9 @@ struct scm_mb_cache {
   ((i) <= (cache)->character && (cache)->character == (cache)->byte	\
    ? &(p)[(i)]								\
    : scm_mb_index_cached_func ((p), (len), (i), (cache)))
-extern unsigned char *scm_mb_index_cached_func (const unsigned char *p,
-						int len, int i, 
-						struct scm_mb_cache *cache);
+extern const unsigned char *scm_mb_index_cached_func (const unsigned char *p,
+						      int len, int i, 
+						      struct scm_mb_cache *cache);
 
 /* Convert a multibyte string to an array of scm_char_t's.
    The caller is responsible for freeing the result.  */