Allow for multiple argument sets in help output.

Alternative invocations follow the main one, each on a separate line,
preceded by " or: ".

* include/mailutils/cli.h (mu_cli_setup) <prog_alt_args>: New member.
* include/mailutils/opt.h (mu_parseopt) <po_prog_args>: Change type.
(mu_program_usage): Change signature.
* include/mailutils/stream.h (MU_IOCTL_WORDWRAP_GET_OFFSET): Rename to
MU_IOCTL_WORDWRAP_GET_COLUMN. All uses changed.
* libmailutils/cli/cli.c (mu_cli): Construct po.po_prog_args from
prog_args and prog_alt_args.
* libmailutils/opt/help.c (move_margin): Remove.
(print_program_usage): New static function.
(mu_program_usage): Second argument instructs how to display options.
Main work is done by print_program_usage.
(mu_program_help): Call print_program_usage.
* libmailutils/opt/opt.c: Update.
* libmailutils/stream/wordwrap.c (set_margin): Avoid unnecessary flushes.

* libmailutils/tests/parseopt.c (MU_PARSEOPT_PROG_ARGS): Alternative
argument sets are separated by the pipe sign.
* libmailutils/tests/Makefile.am: Add new testcase.
* libmailutils/tests/testsuite.at: Likewise.
* libmailutils/tests/parseopt_help04.at: Add MU_PARSEOPT_PROG_ARGS
to keywords.
* libmailutils/tests/parseopt_help12.at: New file.

* libmailutils/tests/tcli.c (cli): Add alternative arguments.

* dotlock/dotlock.c: Update.
* mimeview/mimeview.c: Likewise.
* sieve/sieve.c: Likewise.

@@ -93,6 +93,7 @@ static struct mu_cli_setup cli = {
   dotlock_cfg_param,
   N_("GNU dotlock -- lock mail spool files."),
   N_("FILE"),
+  NULL,
   N_("Returns 0 on success, 3 if locking the file fails because\
  it's already locked, and 1 if some other kind of error occurred."),
   MU_DL_EX_ERROR,

@@ -43,6 +43,7 @@ struct mu_cli_setup
   struct mu_cfg_param *cfg;    /* Configuration parameters */
   char *prog_doc;              /* Program documentation string */
   char *prog_args;             /* Program arguments string */
+  char const **prog_alt_args;  /* Alternative arguments string */
   char *prog_extra_doc;        /* Extra documentation.  This will be
 				  displayed after options. */
   int ex_usage;                /* If not 0, exit code on usage errors */

@@ -125,7 +125,7 @@ struct mu_parseopt
   /* Informational: */
   char const *po_prog_name;
   char const *po_prog_doc;	
-  char const *po_prog_args;
+  char const **po_prog_args;
   char const *po_bug_address;
   char const *po_package_name;
   char const *po_package_url;
@@ -172,7 +172,7 @@ unsigned mu_parseopt_getcolumn (const char *name);
 void mu_option_describe_options (mu_stream_t str,
 				 struct mu_option **optbuf, size_t optcnt);
 void mu_program_help (struct mu_parseopt *p, mu_stream_t str);
-void mu_program_usage (struct mu_parseopt *p, mu_stream_t str);
+void mu_program_usage (struct mu_parseopt *p, int optsummary, mu_stream_t str);
 void mu_program_version (struct mu_parseopt *po, mu_stream_t str);
 
 void mu_option_set_value (struct mu_parseopt *po, struct mu_option *opt,

@@ -208,11 +208,16 @@ enum mu_buffer_type
   ((n) == MU_TRANSPORT_INPUT || (n) == MU_TRANSPORT_OUTPUT)
 
 /* Word wrapper streams */
+/* Get left margin. */
 #define MU_IOCTL_WORDWRAP_GET_MARGIN      0
-#define MU_IOCTL_WORDWRAP_SET_MARGIN      1  
+/* Set left margin */  
+#define MU_IOCTL_WORDWRAP_SET_MARGIN      1
+/* Shift left margin relative to current position */ 
 #define MU_IOCTL_WORDWRAP_MOVE_MARGIN     2
+/* Set left margin for the next line */
 #define MU_IOCTL_WORDWRAP_SET_NEXT_MARGIN 3
-#define MU_IOCTL_WORDWRAP_GET_OFFSET      4
+/* Get current column */
+#define MU_IOCTL_WORDWRAP_GET_COLUMN      4
 
 struct mu_nullstream_pattern
 {

@@ -336,7 +336,11 @@ mu_cli (int argc, char **argv, struct mu_cli_setup *setup, char **capa,
   struct mu_cfg_parse_hints hints;
   struct mu_option **optv;
   mu_list_t com_list;
-
+#define DFLARGC 2
+  char const *dfl_args[DFLARGC];
+  char **args = NULL;
+  size_t argcnt;
+  
   /* Set up defaults */
   if (setup->ex_usage == 0)
     setup->ex_usage = EX_USAGE;
@@ -374,7 +378,28 @@ mu_cli (int argc, char **argv, struct mu_cli_setup *setup, char **capa,
 
   if (setup->prog_args)
     {
-      po.po_prog_args = setup->prog_args;
+      size_t i;
+      argcnt = 1;
+
+      if (setup->prog_alt_args)
+	{
+	  for (i = 0; setup->prog_alt_args[i]; i++)
+	    argcnt++;
+	}
+
+      if (argcnt < DFLARGC)
+	po.po_prog_args = dfl_args;
+      else
+	{
+	  args = mu_calloc (argcnt + 1, sizeof (args[0]));
+	  po.po_prog_args = (char const **) args;
+	}
+      
+      po.po_prog_args[0] = setup->prog_args;
+      for (i = 1; i < argcnt; i++)
+	po.po_prog_args[i] = setup->prog_alt_args[i-1];
+      po.po_prog_args[i] = NULL;
+
       flags |= MU_PARSEOPT_PROG_ARGS;
     }
   
@@ -439,5 +464,8 @@ mu_cli (int argc, char **argv, struct mu_cli_setup *setup, char **capa,
 
   mu_cfg_destroy_tree (&parse_tree);
   free (optv);
+  
+  free (args);
+
   mu_parseopt_free (&po);  
 }

@@ -204,16 +204,9 @@ static void
 get_offset (mu_stream_t str, unsigned *offset)
 {
   mu_stream_ioctl (str, MU_IOCTL_WORDWRAPSTREAM,
-		   MU_IOCTL_WORDWRAP_GET_OFFSET,
+		   MU_IOCTL_WORDWRAP_GET_COLUMN,
 		   offset);
 }
-static void
-move_margin (mu_stream_t str, int margin)
-{
-  mu_stream_ioctl (str, MU_IOCTL_WORDWRAPSTREAM,
-		   MU_IOCTL_WORDWRAP_MOVE_MARGIN,
-		   &margin);
-}
 
 static void
 print_opt_arg (mu_stream_t str, struct mu_option *opt, int delim)
@@ -333,6 +326,9 @@ mu_option_describe_options (mu_stream_t str,
     }
 }
 
+static void print_program_usage (struct mu_parseopt *po, int optsum,
+				 mu_stream_t str);
+
 void
 mu_program_help (struct mu_parseopt *po, mu_stream_t outstr)
 {
@@ -346,15 +342,8 @@ mu_program_help (struct mu_parseopt *po, mu_stream_t outstr)
     {
       abort ();//FIXME
     }
-  
-  mu_stream_printf (str, "%s", _("Usage:"));
-  if (po->po_prog_name)
-    mu_stream_printf (str, " %s ", po->po_prog_name);
-  move_margin (str, 0);
-  mu_stream_printf (str, "[%s]...", _("OPTION"));
-  if (po->po_prog_args)
-    mu_stream_printf (str, " %s", gettext (po->po_prog_args));
-  mu_stream_printf (str, "\n");
+
+  print_program_usage (po, 0, str);
   
   if (po->po_prog_doc)
     {
@@ -423,34 +412,20 @@ cmpidx_long (const void *a, const void *b)
   return strcmp (ap->opt_long, bp->opt_long);
 }
 
-void
-mu_program_usage (struct mu_parseopt *po, mu_stream_t outstr)
+static void
+option_summary (struct mu_parseopt *po, mu_stream_t str)
 {
-  int rc;
   unsigned i;
   unsigned *idxbuf;
   unsigned nidx;
 
   struct mu_option **optbuf = po->po_optv;
   size_t optcnt = po->po_optc;
-
-  mu_stream_t str;
-
-  init_usage_vars (po);
-
-  rc = mu_wordwrap_stream_create (&str, outstr, 0, rmargin);
-  if (rc)
-    {
-      abort ();//FIXME
-    }  
   
   option_tab = optbuf;
   
   idxbuf = mu_calloc (optcnt, sizeof (idxbuf[0]));
 
-  mu_stream_printf (str, "%s %s ", _("Usage:"),	po->po_prog_name);
-  set_next_margin (str, usage_indent);
-  
   /* Print a list of short options without arguments. */
   for (i = nidx = 0; i < optcnt; i++)
     if (MU_OPTION_IS_VALID_SHORT_OPTION (optbuf[i]) && !optbuf[i]->opt_arg)
@@ -517,12 +492,66 @@ mu_program_usage (struct mu_parseopt *po, mu_stream_t outstr)
 	}
     }
 
+  free (idxbuf);
+}  
+
+static void
+print_program_usage (struct mu_parseopt *po, int optsum, mu_stream_t str)
+{
+  char const *usage_text;
+  char const **arg_text;
+  size_t i;
+  
+  usage_text = _("Usage:");
+
   if (po->po_flags & MU_PARSEOPT_PROG_ARGS)
-    mu_stream_printf (str, " %s", _(po->po_prog_args));
+    arg_text = po->po_prog_args;
+  else
+    arg_text = NULL;
+  i = 0;
+  
+  do
+    {
+      mu_stream_printf (str, "%s %s ", usage_text, po->po_prog_name);
+      set_next_margin (str, usage_indent);
 
-  mu_stream_destroy (&str);
+      if (optsum)
+	{
+	  option_summary (po, str);
+	  optsum = 0;
+	}
+      else
+	mu_stream_printf (str, "[%s]...", _("OPTION"));
+
+      if (arg_text)
+	{
+	  mu_stream_printf (str, " %s\n", gettext (arg_text[i]));
+	  if (i == 0)
+	    usage_text = _("or: ");
+	  set_margin (str, 2);
+	  i++;
+	}
+      else
+	mu_stream_flush (str);
+    }
+  while (arg_text && arg_text[i]);
+}
+
+void
+mu_program_usage (struct mu_parseopt *po, int optsum, mu_stream_t outstr)
+{
+  int rc;
+  mu_stream_t str;
   
-  free (idxbuf);
+  init_usage_vars (po);
+
+  rc = mu_wordwrap_stream_create (&str, outstr, 0, rmargin);
+  if (rc)
+    {
+      abort ();//FIXME
+    }  
+  print_program_usage (po, optsum, str);
+  mu_stream_destroy (&str);
 }
 
 void

@@ -87,7 +87,7 @@ fn_help (struct mu_parseopt *po, struct mu_option *opt, char const *unused)
 static void
 fn_usage (struct mu_parseopt *po, struct mu_option *opt, char const *unused)
 {
-  mu_program_usage (po, mu_strout);
+  mu_program_usage (po, 1, mu_strout);
   exit (EXIT_SUCCESS);
 }
 

@@ -178,18 +178,20 @@ set_margin (mu_stream_t stream, unsigned lmargin, int off)
   if (lmargin >= str->right_margin)
     return EINVAL;
 
-  str->left_margin = lmargin;
-  if (lmargin < str->offset ||
-      (str->offset > 0 && str->buffer[str->offset - 1] == '\n'))
+  if (str->offset > str->left_margin
+      && (lmargin < str->offset || str->buffer[str->offset - 1] == '\n'))
     {
+      str->left_margin = lmargin;
       _wordwrap_flush (stream);
     }
-  else if (lmargin > str->offset)
+  else
     {
-      memset (str->buffer + str->offset, ' ', lmargin - str->offset);
+      if (lmargin > str->offset)
+	memset (str->buffer + str->offset, ' ', lmargin - str->offset);
+      str->left_margin = lmargin;
       str->offset = lmargin;
     }
-      
+
   return 0;
 }
 
@@ -236,7 +238,7 @@ _wordwrap_ctl (mu_stream_t stream, int code, int opcode, void *arg)
 	  else
 	    return set_margin (stream, str->offset, *(int*)arg);
 
-	case MU_IOCTL_WORDWRAP_GET_OFFSET:
+	case MU_IOCTL_WORDWRAP_GET_COLUMN:
 	  if (!arg)
 	    return EINVAL;
 	  *(unsigned*)arg = str->offset;

@@ -18,6 +18,7 @@ imapio
 listop
 mailcap
 mimehdr
+modmesg
 modtofsaf
 msgset
 parseopt
@@ -32,4 +33,5 @@ tempfile
 url-comp
 url-parse
 wicket
+wordwrap
 wsp

@@ -144,6 +144,7 @@ TESTSUITE_AT = \
  parseopt_help09.at\
  parseopt_help10.at\
  parseopt_help11.at\
+ parseopt_help12.at\
  prop.at\
  scantime.at\
  strftime.at\

@@ -77,8 +77,43 @@ struct parseopt_param
   int flag;
   mu_c_type_t type;
   size_t off;
+  void (*setfn) (struct parseopt_param *param, char const *val, void *target);
 };
 
+static void
+set_prog_args (struct parseopt_param *param, char const *str, void *target)
+{
+  char ***args_ptr = target;
+  char **args;
+  char *p;
+  size_t size, i;
+
+  size = 1;
+  for (i = 0; str[i]; i++)
+    if (str[i] == '\n')
+      size++;
+
+  args = mu_calloc (size + 1, sizeof (args[0]));
+
+  i = 0;
+  while (1)
+    {
+      size_t len = strcspn (str, "|");
+      p = mu_alloc (len + 1);
+      memcpy (p, str, len);
+      p[len] = 0;
+      args[i++] = p;
+      str += len;
+      if (str[0])
+	++str;
+      else
+	break;
+    }
+  args[i] = NULL;
+  
+  *args_ptr = args;
+}
+  
 static struct parseopt_param parseopt_param[] = {
   { "MU_PARSEOPT_ARGV0", MU_PARSEOPT_ARGV0, mu_c_void },
   { "MU_PARSEOPT_IGNORE_ERRORS", MU_PARSEOPT_IGNORE_ERRORS, mu_c_void },
@@ -93,7 +128,8 @@ static struct parseopt_param parseopt_param[] = {
   { "MU_PARSEOPT_PROG_DOC", MU_PARSEOPT_PROG_DOC,
     mu_c_string, mu_offsetof(struct mu_parseopt, po_prog_doc) },
   { "MU_PARSEOPT_PROG_ARGS", MU_PARSEOPT_PROG_ARGS,
-    mu_c_string, mu_offsetof(struct mu_parseopt, po_prog_args) },
+    mu_c_string, mu_offsetof(struct mu_parseopt, po_prog_args),
+    set_prog_args },
   { "MU_PARSEOPT_BUG_ADDRESS", MU_PARSEOPT_BUG_ADDRESS,
     mu_c_string, mu_offsetof(struct mu_parseopt, po_bug_address) },
   { "MU_PARSEOPT_PACKAGE_NAME", MU_PARSEOPT_PACKAGE_NAME,
@@ -129,7 +165,11 @@ main (int argc, char *argv[])
 	  if (val)
 	    {
 	      flags |= param->flag;
-	      if (param->type != mu_c_void)
+	      if (param->setfn)
+		{
+		  param->setfn (param, val, ((char*)&po + param->off));
+		}
+	      else if (param->type != mu_c_void)
 		{
 		  char *errmsg;
 		  int rc = mu_str_to_c (val, param->type,

@@ -15,7 +15,7 @@
 # along with GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
 
 AT_SETUP([MU_PARSEOPT_PROG_ARGS])
-AT_KEYWORDS([parseopt parseopt_help parseopt_help04])
+AT_KEYWORDS([parseopt parseopt_help MU_PARSEOPT_PROG_ARGS parseopt_help04])
 AT_CHECK([
 PARSEOPT_DEFAULT
 MU_PARSEOPT_PROG_ARGS="SOME MORE ARGS" parseopt --help

+# This file is part of GNU Mailutils. -*- Autotest -*-
+# Copyright (C) 2016 Free Software Foundation, Inc.
+#
+# GNU Mailutils 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 3, or (at
+# your option) any later version.
+#
+# GNU Mailutils 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 GNU Mailutils.  If not, see <http://www.gnu.org/licenses/>.
+
+AT_SETUP([MU_PARSEOPT_PROG_ARGS (alternative)])
+AT_KEYWORDS([parseopt parseopt_help MU_PARSEOPT_PROG_ARGS parseopt_help12])
+AT_CHECK([
+PARSEOPT_DEFAULT
+MU_PARSEOPT_PROG_ARGS="SOME MORE ARGS|ALTERNATIVE ARGS|ANOTHER ARGS" parseopt --help
+],
+[0],
+[Usage: parseopt [[OPTION]]... SOME MORE ARGS
+  or:  parseopt [[OPTION]]... ALTERNATIVE ARGS
+  or:  parseopt [[OPTION]]... ANOTHER ARGS
+  
+ Group A
+  -a, --all                  no arguments to this one
+  -f, --file=FILE            set file name
+  -o, --optional[[=FILE]]      optional argument
+  -x                         short-only option
+
+ Group B
+  -d, -v, --debug, --verbose another option
+  -F, --find=VALUE           find VALUE
+  -j, --jobs=N               sets numeric value
+
+  -?, --help                 give this help list
+      --usage                give a short usage message
+
+Mandatory or optional arguments to long options are also mandatory or optional
+for any corresponding short options.
+
+])
+AT_CLEANUP
+
+

@@ -37,11 +37,14 @@ static struct mu_cfg_param config[] = {
   { NULL }
 };
 
+char const *alt_args[] = { "ALT ARGUMENTS 1", "ALT ARGUMENTS 2", NULL };
+
 struct mu_cli_setup cli = {
   options,
   config,
   "Tests standard command line interface",
-  "ARGUMENTS"
+  "ARGUMENTS",
+  alt_args
 };
 
 static char **

@@ -121,6 +121,7 @@ m4_include([parseopt_help08.at])
 m4_include([parseopt_help09.at])
 m4_include([parseopt_help10.at])
 m4_include([parseopt_help11.at])
+m4_include([parseopt_help12.at])
 
 AT_BANNER([Standard streams])
 m4_include([strin.at])

@@ -145,6 +145,7 @@ struct mu_cli_setup cli = {
   mimeview_cfg_param,
   N_("GNU mimeview -- display files, using mailcap mechanism."),
   N_("FILE [FILE ...]"),
+  NULL,
   N_("Debug flags are:\n\
   g - Mime.types parser traces\n\
   l - Mime.types lexical analyzer traces\n\

@@ -248,6 +248,7 @@ static struct mu_cli_setup cli = {
   sieve_cfg_param,
   N_("GNU sieve -- a mail filtering tool."),
   "SCRIPT",
+  NULL,
   N_("Debug flags:\n\
   g - main parser traces\n\
   T - mailutils traces (same as --debug-level=sieve.trace0-trace1)\n\