Support for single-dash long options (as in MH) and negation for boolean options.

* include/mailutils/opt.h (MU_PARSEOPT_SINGLE_DASH)
(MU_PARSEOPT_NEGATION): New flags.
(mu_parseopt) <po_negation, po_long_opt_start>: New fields.
(mu_option_describe_options): Change signature.
* libmailutils/opt/help.c (init_usage_vars): Initialize
long_opt_col depending on the value of MU_PARSEOPT_SINGLE_DASH
bit.
(print_option): Handle single-dash long options and boolean
options with negations.
(option_summary): Likewise.
(mu_option_describe_options): Take struct mu_parseopt *
as its second parameter.
* libmailutils/opt/opt.c (find_long_option): Handle
boolean options with negations.  Return also a pointer
to the mu_option describing the originally used option
(as opposed to the canonical one returned by the function).
(parse): Handle single-dash long options.
(parseopt_init): Initialize po_negation and po_long_opt_start.
* libmailutils/tests/parseopt.c (parseopt_param): Handle
MU_PARSEOPT_SINGLE_DASH and MU_PARSEOPT_NEGATION.

@@ -103,13 +103,17 @@ struct mu_option_cache
 #define MU_PARSEOPT_DATA           0x00400000
 #define MU_PARSEOPT_VERSION_HOOK   0x00800000
 #define MU_PARSEOPT_PROG_DOC_HOOK  0x01000000
+/* Long options start with single dash.  Disables recognition of traditional
+   short options */
+#define MU_PARSEOPT_SINGLE_DASH    0x02000000
+/* Negation prefix is set */
+#define MU_PARSEOPT_NEGATION       0x04000000
 
 /* Reuse mu_parseopt struct initialized previously */
 #define MU_PARSEOPT_REUSE          0x80000000
 /* Mask for immutable flag bits */
 #define MU_PARSEOPT_IMMUTABLE_MASK 0xFFFFF000
 
-
 struct mu_parseopt
 {
   /* Input data: */
@@ -119,6 +123,7 @@ struct mu_parseopt
   struct mu_option **po_optv;      /* Array of ptrs to option structures */ 
   int po_flags;                        
 
+  char *po_negation;               /* Negation prefix for boolean options */
   void *po_data;                   /* Call-specific data */
 
   int po_exit_error;               /* Exit on error with this code */
@@ -145,6 +150,9 @@ struct mu_parseopt
   /* Auxiliary data */
   char *po_cur;                    /* Points to the next character */
   int po_chr;                      /* Single-char option */
+
+  char *po_long_opt_start;         /* Character sequence that starts
+				      long option */
   
   /* The following two keep the position of the first non-optional argument
      and the number of contiguous non-optional arguments after it.
@@ -161,6 +169,7 @@ struct mu_parseopt
   unsigned po_permuted:1;           /* Whether the arguments were permuted */
 };
 
+
 int mu_parseopt (struct mu_parseopt *p,
 		 int argc, char **argv, struct mu_option **optv,
 		 int flags);
@@ -171,8 +180,7 @@ void mu_parseopt_free (struct mu_parseopt *p);
 
 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_option_describe_options (mu_stream_t str, struct mu_parseopt *p);
 void mu_program_help (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);
@@ -180,4 +188,6 @@ 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,
 			  char const *arg);
 
+int mu_option_possible_negation (struct mu_parseopt *po, struct mu_option *opt);
+
 #endif

@@ -30,7 +30,7 @@
 #include <mailutils/stream.h>
 
 unsigned short_opt_col = 2;
-unsigned long_opt_col = 6;
+unsigned long_opt_col; /* Initialized in init_usage_vars */
 /*FIXME: doc_opt_col? */
 unsigned header_col = 1;
 unsigned opt_doc_col = 29;
@@ -170,6 +170,11 @@ init_usage_vars (struct mu_parseopt *po)
   struct mu_wordsplit ws;
   size_t i;
   
+  if (po->po_flags & MU_PARSEOPT_SINGLE_DASH)
+    long_opt_col = 2;
+  else
+    long_opt_col = 6;
+
   fmt = getenv ("ARGP_HELP_FMT");
   if (!fmt)
     return;
@@ -223,11 +228,10 @@ print_opt_arg (mu_stream_t str, struct mu_option *opt, int delim)
 }
 
 static size_t
-print_option (mu_stream_t str,
-	      struct mu_option **optbuf, size_t optcnt, size_t num,
+print_option (mu_stream_t str, struct mu_parseopt *po, size_t num,
 	      int *argsused)
 {
-  struct mu_option *opt = optbuf[num];
+  struct mu_option *opt = po->po_optv[num];
   size_t next, i;
   int delim;
   int first_option = 1;
@@ -240,38 +244,47 @@ print_option (mu_stream_t str,
       if (opt->opt_doc[0])
 	{
 	  set_margin (str, header_col);
-	  mu_stream_printf (str, "%s", gettext (opt->opt_doc));
+	  mu_stream_printf (str, "%s\n", gettext (opt->opt_doc));
 	}
       return num + 1;
     }
 
   /* count aliases */
   for (next = num + 1;
-       next < optcnt && optbuf[next]->opt_flags & MU_OPTION_ALIAS;
+       next < po->po_optc && po->po_optv[next]->opt_flags & MU_OPTION_ALIAS;
        next++);
 
   if (opt->opt_flags & MU_OPTION_HIDDEN)
     return next;
 
-  set_margin (str, short_opt_col); 
-  for (i = num; i < next; i++)
+  if (po->po_flags & MU_PARSEOPT_SINGLE_DASH)
+    {
+      if (!opt->opt_long)
+	return num + 1; /* Ignore erroneous option */
+      set_margin (str, long_opt_col);
+    }
+  else
     {
-      if (MU_OPTION_IS_VALID_SHORT_OPTION (optbuf[i]))
+      set_margin (str, short_opt_col); 
+      for (i = num; i < next; i++)
 	{
-	  if (first_option)
-	    first_option = 0;
-	  else
-	    mu_stream_printf (str, ", ");
-	  mu_stream_printf (str, "-%c", optbuf[i]->opt_short);
-	  delim = ' ';
-	  if (opt->opt_arg && dup_args)
-	    print_opt_arg (str, opt, delim);
+	  if (MU_OPTION_IS_VALID_SHORT_OPTION (po->po_optv[i]))
+	    {
+	      if (first_option)
+		first_option = 0;
+	      else
+		mu_stream_printf (str, ", ");
+	      mu_stream_printf (str, "-%c", po->po_optv[i]->opt_short);
+	      delim = ' ';
+	      if (opt->opt_arg && dup_args)
+		print_opt_arg (str, opt, delim);
+	    }
 	}
     }
-
+  
   for (i = num; i < next; i++)
     {
-      if (MU_OPTION_IS_VALID_LONG_OPTION (optbuf[i]))
+      if (MU_OPTION_IS_VALID_LONG_OPTION (po->po_optv[i]))
 	{
 	  if (first_option)
 	    first_option = 0;
@@ -287,8 +300,12 @@ print_option (mu_stream_t str,
 	      first_long_option = 0;
 	    }
 	  
-  	  mu_stream_printf (str, "--%s", optbuf[i]->opt_long);
-	  delim = '=';
+  	  mu_stream_printf (str, "%s", po->po_long_opt_start);
+	  if (mu_option_possible_negation (po, po->po_optv[i]))
+	    mu_stream_printf (str, "[%s]", po->po_negation);
+  	  mu_stream_printf (str, "%s", po->po_optv[i]->opt_long);	  
+	  delim = ((po->po_flags & MU_PARSEOPT_SINGLE_DASH)
+		   && !(opt->opt_flags & MU_OPTION_ARG_OPTIONAL)) ? ' ' : '=';
 	  if (opt->opt_arg && dup_args)
 	    print_opt_arg (str, opt, delim);
 	}
@@ -308,14 +325,13 @@ print_option (mu_stream_t str,
 }
 
 void
-mu_option_describe_options (mu_stream_t str,
-			    struct mu_option **optbuf, size_t optcnt)
+mu_option_describe_options (mu_stream_t str, struct mu_parseopt *po)
 {
   unsigned i;
   int argsused = 0;
 
-  for (i = 0; i < optcnt; )
-    i = print_option (str, optbuf, optcnt, i, &argsused);
+  for (i = 0; i < po->po_optc; )
+    i = print_option (str, po, i, &argsused);
   mu_stream_printf (str, "\n");
 
   if (argsused && dup_args_note)
@@ -334,7 +350,7 @@ mu_program_help (struct mu_parseopt *po, mu_stream_t outstr)
 {
   mu_stream_t str;
   int rc;
-  
+
   init_usage_vars (po);
 
   rc = mu_wordwrap_stream_create (&str, outstr, 0, rmargin);
@@ -358,7 +374,7 @@ mu_program_help (struct mu_parseopt *po, mu_stream_t outstr)
       mu_stream_printf (str, "\n");
     }
   
-  mu_option_describe_options (str, po->po_optv, po->po_optc);
+  mu_option_describe_options (str, po);
 
   if (po->po_help_hook)
     {
@@ -432,41 +448,44 @@ option_summary (struct mu_parseopt *po, mu_stream_t str)
   
   idxbuf = mu_calloc (optcnt, sizeof (idxbuf[0]));
 
-  /* 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)
-      idxbuf[nidx++] = i;
-
-  if (nidx)
+  if (!(po->po_flags & MU_PARSEOPT_SINGLE_DASH))
     {
-      qsort (idxbuf, nidx, sizeof (idxbuf[0]), cmpidx_short);
-      mu_stream_printf (str, "[-");
-      for (i = 0; i < nidx; i++)
+      /* 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)
+	  idxbuf[nidx++] = i;
+      
+      if (nidx)
 	{
-	  mu_stream_printf (str, "%c", optbuf[idxbuf[i]]->opt_short);
+	  qsort (idxbuf, nidx, sizeof (idxbuf[0]), cmpidx_short);
+	  mu_stream_printf (str, "[-");
+	  for (i = 0; i < nidx; i++)
+	    {
+	      mu_stream_printf (str, "%c", optbuf[idxbuf[i]]->opt_short);
+	    }
+	  mu_stream_printf (str, "%c", ']');
 	}
-      mu_stream_printf (str, "%c", ']');
-    }
 
-  /* Print a list of short options with arguments. */
-  for (i = nidx = 0; i < optcnt; i++)
-    {
-      if (MU_OPTION_IS_VALID_SHORT_OPTION (optbuf[i]) && optbuf[i]->opt_arg)
-	idxbuf[nidx++] = i;
-    }
+      /* Print a list of short options with arguments. */
+      for (i = nidx = 0; i < optcnt; i++)
+	{
+	  if (MU_OPTION_IS_VALID_SHORT_OPTION (optbuf[i]) && optbuf[i]->opt_arg)
+	    idxbuf[nidx++] = i;
+	}
 
-  if (nidx)
-    {
-      qsort (idxbuf, nidx, sizeof (idxbuf[0]), cmpidx_short);
-    
-      for (i = 0; i < nidx; i++)
+      if (nidx)
 	{
-	  struct mu_option *opt = optbuf[idxbuf[i]];
-	  const char *arg = gettext (opt->opt_arg);
-	  if (opt->opt_flags & MU_OPTION_ARG_OPTIONAL)
-	    mu_stream_printf (str, " [-%c[%s]]", opt->opt_short, arg);
-	  else
-	    mu_stream_printf (str, " [-%c %s]", opt->opt_short, arg);
+	  qsort (idxbuf, nidx, sizeof (idxbuf[0]), cmpidx_short);
+	  
+	  for (i = 0; i < nidx; i++)
+	    {
+	      struct mu_option *opt = optbuf[idxbuf[i]];
+	      const char *arg = gettext (opt->opt_arg);
+	      if (opt->opt_flags & MU_OPTION_ARG_OPTIONAL)
+		mu_stream_printf (str, " [-%c[%s]]", opt->opt_short, arg);
+	      else
+		mu_stream_printf (str, " [-%c %s]", opt->opt_short, arg);
+	    }
 	}
     }
   
@@ -486,11 +505,17 @@ option_summary (struct mu_parseopt *po, mu_stream_t str)
 	  struct mu_option *opt = optbuf[idxbuf[i]];
 	  const char *arg = opt->opt_arg ? gettext (opt->opt_arg) : NULL;
 
-	  mu_stream_printf (str, " [--%s", opt->opt_long);
+	  mu_stream_printf (str, " [%s", po->po_long_opt_start);
+	  if (mu_option_possible_negation (po, opt))
+	    mu_stream_printf (str, "[%s]", po->po_negation);
+	  mu_stream_printf (str, "%s", opt->opt_long);
+
 	  if (opt->opt_arg)
 	    {
 	      if (opt->opt_flags & MU_OPTION_ARG_OPTIONAL)
 		mu_stream_printf (str, "[=%s]", arg);
+	      else if (po->po_flags & MU_PARSEOPT_SINGLE_DASH)
+		mu_stream_printf (str, " %s", arg);
 	      else
 		mu_stream_printf (str, "=%s", arg);
 	    }

@@ -193,58 +193,94 @@ find_short_option (struct mu_parseopt *po, int chr)
    it in *ARGPTR. */
 struct mu_option *
 find_long_option (struct mu_parseopt *po, char const *optstr,
-		  char **argptr)
+		  struct mu_option **used_opt_ptr,
+		  char **used_value,
+		  char **value)
 {
   size_t i;
-  size_t optlen;
-  size_t ind;
-  int found = 0;
+  size_t optlen;       /* Length of the option in optstr */
+  int found = 0;       /* 1 if the match was found, 2 if option is ambiguous */
+  int neglen;          /* Length of the negation prefix, if any */
+  int neg = 0;         /* 1 if a boolean option is negated */
+  struct mu_option *ret_opt = NULL;
+  struct mu_option *used_opt;
   
   optlen = strcspn (optstr, "=");
+  if (po->po_negation)
+    neglen = strlen (po->po_negation);
   
   for (i = 0; i < po->po_optc; i++)
     {
-      if (MU_OPTION_IS_VALID_LONG_OPTION (po->po_optv[i])
-	  && optlen <= strlen (po->po_optv[i]->opt_long)
-	  && memcmp (po->po_optv[i]->opt_long, optstr, optlen) == 0)
+      if (MU_OPTION_IS_VALID_LONG_OPTION (po->po_optv[i]))
 	{
-	  switch (found)
+	  size_t len = strlen (po->po_optv[i]->opt_long);
+	  struct mu_option *opt = option_unalias (po, i);
+	  
+	  if ((optlen <= len
+	       && memcmp (po->po_optv[i]->opt_long, optstr, optlen) == 0)
+	      || (neg = (mu_option_possible_negation (po, opt)
+			 && optlen <= neglen + len
+			 && memcmp (optstr, po->po_negation, neglen) == 0
+			 && memcmp (optstr + neglen, po->po_optv[i]->opt_long,
+				    optlen - neglen) == 0)))
 	    {
-	    case 0:
-	      ind = i;
-	      found++;
-	      if (optlen == strlen (po->po_optv[i]->opt_long))
-		i = po->po_optc - 1; /* exact match: break the loop */
-	      break;
-
-	    case 1:
-	      if (option_unalias (po, i) == option_unalias (po, ind))
-		continue;
-	      if (po->po_flags & MU_PARSEOPT_IGNORE_ERRORS)
-		return NULL;
-	      mu_parseopt_error (po,
-			   _("option '--%*.*s' is ambiguous; possibilities:"),
-			   optlen, optlen, optstr);
-	      fprintf (stderr, "--%s\n", po->po_optv[ind]->opt_long);
-	      found++;
-
-	    case 2:
-	      fprintf (stderr, "--%s\n", po->po_optv[i]->opt_long);
+	      switch (found)
+		{
+		case 0:
+		  used_opt = po->po_optv[i];
+		  ret_opt = opt;
+		  found++;
+		  if (optlen == len || (neg && optlen == neglen + len))
+		    i = po->po_optc - 1; /* exact match: break the loop */
+		  break;
+		  
+		case 1:
+		  if (opt == ret_opt)
+		    continue;
+		  if (po->po_flags & MU_PARSEOPT_IGNORE_ERRORS)
+		    return NULL;
+		  mu_parseopt_error (po,
+				     _("option '%s%*.*s' is ambiguous; possibilities:"),
+				     po->po_long_opt_start,
+				     optlen, optlen, optstr);
+		  fprintf (stderr, "%s%s%s\n",
+			   po->po_long_opt_start,
+			   neg ? po->po_negation : "",
+			   used_opt->opt_long);
+		  found++;
+		  
+		case 2:
+		  fprintf (stderr, "%s%s%s\n",
+			   po->po_long_opt_start,
+			   neg ? po->po_negation : "",
+			   po->po_optv[i]->opt_long);
+		}
 	    }
 	}
     }
-
+  
   switch (found)
     {
     case 0:
-      mu_parseopt_error (po, _("unrecognized option '--%s'"), optstr);
+      mu_parseopt_error (po, _("unrecognized option '%s%s'"),
+			 po->po_long_opt_start, optstr);
       break;
       
     case 1:
+      *used_opt_ptr = used_opt;
       if (optstr[optlen])
 	++optlen;
-      *argptr = (char *)(optstr + optlen);
-      return option_unalias (po, ind);
+      *used_value = (char *)(optstr + optlen);
+      if (ret_opt->opt_type == mu_c_bool)
+	{
+	  if (neg)
+	    *value = "0";
+	  else
+	    *value = "1";
+	}
+      else
+	*value = NULL;
+      return ret_opt;
 
     case 2:
       break;
@@ -313,7 +349,36 @@ next_opt (struct mu_parseopt *po)
 	  if (!po->po_cur)
 	    return 1;
 	  if (po->po_cur[0] == '-' && po->po_cur[1])
-	    break;
+	    {
+	      if (*++po->po_cur == '-')
+		{
+		  if (*++po->po_cur == 0)
+		    {
+		      /* End of options */
+		      permute (po);
+		      ++po->po_ind;
+		      return 1;
+		    }
+		  
+		  if (po->po_flags & MU_PARSEOPT_SINGLE_DASH)
+		    /* a non-optional argument */;
+		  else
+		    {
+		      /* It's a long option */
+		      po->po_chr = 0;
+		      return 0;
+		    }
+		}
+	      else if (po->po_flags & MU_PARSEOPT_SINGLE_DASH)
+		{
+		  /* Assume single-dash long option */
+		  po->po_chr = 0;
+		  return 0;
+		}
+	      else
+		break;
+	    }
+
 	  if (!(po->po_flags & MU_PARSEOPT_IN_ORDER))
 	    {
 	      if (!po->po_permuted && po->po_arg_count == 0)
@@ -324,21 +389,6 @@ next_opt (struct mu_parseopt *po)
 	  else
 	    return 1;
 	}
-
-      if (*++po->po_cur == '-')
-	{
-	  if (*++po->po_cur == 0)
-	    {
-	      /* End of options */
-	      permute (po);
-	      ++po->po_ind;
-	      return 1;
-	    }
-
-	  /* It's a long option */
-	  po->po_chr = 0;
-	  return 0;
-	}
     }
 
   po->po_chr = *po->po_cur++;
@@ -386,18 +436,18 @@ parse (struct mu_parseopt *po)
   
   while (next_opt (po) == 0)
     {
-      struct mu_option *opt;
-      char *long_opt;
+      struct mu_option *opt, *uopt;
+      char *value;
       
       if (po->po_chr)
 	{
 	  opt = find_short_option (po, po->po_chr);
-	  long_opt = NULL;
+	  uopt = NULL;
+	  value = NULL;
 	}
       else
 	{
-	  long_opt = po->po_cur;
-	  opt = find_long_option (po, long_opt, &po->po_cur);
+	  opt = find_long_option (po, po->po_cur, &uopt, &po->po_cur, &value);
 	}
 
       if (opt)
@@ -417,14 +467,14 @@ parse (struct mu_parseopt *po)
 		arg = po->po_argv[po->po_ind++];
 	      else
 		{
-		  if (long_opt)
+		  if (uopt)
 		    mu_parseopt_error (po,
-				 _("option '--%s' requires an argument"),
-				 long_opt);
+				 _("option '%s%s' requires an argument"),
+				       po->po_long_opt_start, uopt->opt_long);
 		  else
 		    mu_parseopt_error (po,
 				 _("option '-%c' requires an argument"),
-				 po->po_chr);
+				       po->po_chr);
 		  po->po_opterr = po->po_ind;
 		  if (po->po_flags & MU_PARSEOPT_NO_ERREXIT)
 		    {
@@ -437,13 +487,14 @@ parse (struct mu_parseopt *po)
 	    }
 	  else
 	    {
-	      if (long_opt
+	      if (uopt
 		  && po->po_cur[0]
 		  && !(po->po_flags & MU_OPTION_ARG_OPTIONAL))
 		{
 		  mu_parseopt_error (po,
-			       _("option '--%s' doesn't allow an argument"),
-			       long_opt);
+			       _("option '%s%s' doesn't allow an argument"),
+				     po->po_long_opt_start,
+				     uopt->opt_long);
 		  po->po_opterr = po->po_ind;
 		  if (po->po_flags & MU_PARSEOPT_NO_ERREXIT)
 		    {
@@ -455,6 +506,9 @@ parse (struct mu_parseopt *po)
 		}
 	      arg = NULL;
 	    }
+
+	  if (!arg && value)
+	    arg = value;
 	  
 	  add_option_cache (po, opt, arg);
 	}
@@ -515,6 +569,13 @@ parseopt_init (struct mu_parseopt *po, struct mu_option **options,
     po->po_version_hook = NULL;
   if (!(flags & MU_PARSEOPT_PROG_DOC_HOOK))
     po->po_prog_doc_hook = NULL;
+  if (!(flags & MU_PARSEOPT_NEGATION))
+    po->po_negation = NULL;
+  
+  if (flags & MU_PARSEOPT_SINGLE_DASH)
+    po->po_long_opt_start = "-";
+  else
+    po->po_long_opt_start = "--";    
   
   /* Count the options */
   po->po_optc = 0;
@@ -686,3 +747,9 @@ mu_option_set_value (struct mu_parseopt *po, struct mu_option *opt,
 	}
     }
 }
+
+int
+mu_option_possible_negation (struct mu_parseopt *po, struct mu_option *opt)
+{
+  return po->po_negation && opt->opt_type == mu_c_bool && !opt->opt_arg;
+}

@@ -141,6 +141,10 @@ static struct parseopt_param parseopt_param[] = {
   { "MU_PARSEOPT_EXIT_ERROR", MU_PARSEOPT_EXIT_ERROR,
     mu_c_int, mu_offsetof(struct mu_parseopt, po_exit_error) },
   { "MU_PARSEOPT_VERSION_HOOK", MU_PARSEOPT_VERSION_HOOK, mu_c_void },
+  { "MU_PARSEOPT_SINGLE_DASH", MU_PARSEOPT_SINGLE_DASH, mu_c_void },
+  { "MU_PARSEOPT_NEGATION", MU_PARSEOPT_NEGATION,
+    mu_c_string, mu_offsetof(struct mu_parseopt, po_negation) },
+    
   { NULL }
 };