#
#
# patch "option.cc"
#  from [6697c789f4b6dd082bbab6c2c7bea70dc549b308]
#    to [5f78f36e5c5a6ba6000ed6bba4354965cd96636a]
# 
# patch "option.hh"
#  from [a120f75cc822a8ff7a0e0602d2385f3d730f2588]
#    to [4b8b3b06e05e716358a3da600f0c0a948104af8c]
#
============================================================
--- option.cc	6697c789f4b6dd082bbab6c2c7bea70dc549b308
+++ option.cc	5f78f36e5c5a6ba6000ed6bba4354965cd96636a
@@ -53,9 +53,15 @@ bad_arg_internal::bad_arg_internal(strin
 
 
 
-void splitname(char const * f, string & name, string & n)
+void splitname(char const * f, string & name, string & n, string & cancel)
 {
   string from(f);
+  if (from.find("/") != string::npos)
+    {
+      string::size_type slash = from.find("/");
+      cancel = from.substr(slash+1);
+      from.erase(slash);
+    }
   // from looks like "foo" or "foo,f"
   string::size_type comma = from.find(',');
   name = from.substr(0, comma);
@@ -86,8 +92,10 @@ concrete_option::concrete_option(char co
                                  boost::function<void ()> reset)
 {
   description = desc;
-  splitname(names, longname, shortname);
+  splitname(names, longname, shortname, cancelname);
   I((desc && desc[0]) || !longname.empty() || !shortname.empty());
+  // not sure how to display if it can only be reset (and what would that mean?)
+  I((!longname.empty() || !shortname.empty()) || cancelname.empty());
   // If an option has a name (ie, can be set), it must have a setter function
   I(set || (longname.empty() && shortname.empty()));
   has_arg = arg;
@@ -101,6 +109,8 @@ bool concrete_option::operator<(concrete
     return longname < other.longname;
   if (shortname != other.shortname)
     return shortname < other.shortname;
+  if (cancelname != other.cancelname)
+    return cancelname < other.cancelname;
   return description < other.description;
 }
 
@@ -272,6 +282,8 @@ get_by_name(std::set<concrete_option> co
         by_name.insert(make_pair(i->longname, *i));
       if (!i->shortname.empty())
         by_name.insert(make_pair(i->shortname, *i));
+      if (!i->cancelname.empty())
+        by_name.insert(make_pair(i->cancelname, *i));
     }
   return by_name;
 }
@@ -287,6 +299,7 @@ void concrete_option_set::from_command_l
       concrete_option o;
       string name;
       arg_type arg;
+      bool is_cancel;
       bool separate_arg(false);
       if (idx(args,i)() == "--" || seen_dashdash)
         {
@@ -299,6 +312,7 @@ void concrete_option_set::from_command_l
           name = "--";
           o = getopt(by_name, name);
           arg = idx(args,i);
+          is_cancel = false;
         }
       else if (idx(args,i)().substr(0,2) == "--")
         {
@@ -309,10 +323,11 @@ void concrete_option_set::from_command_l
             name = idx(args,i)().substr(2, equals-2);
 
           o = getopt(by_name, name);
-          if (!o.has_arg && equals != string::npos)
+          is_cancel = (name == o.cancelname);
+          if ((!o.has_arg || is_cancel) && equals != string::npos)
             throw extra_arg(name);
 
-          if (o.has_arg)
+          if (o.has_arg && !is_cancel)
             {
               if (equals == string::npos)
                 {
@@ -330,6 +345,8 @@ void concrete_option_set::from_command_l
           name = idx(args,i)().substr(1,1);
 
           o = getopt(by_name, name);
+          is_cancel = (name == o.cancelname);
+          I(!is_cancel);
           if (!o.has_arg && idx(args,i)().size() != 2)
             throw extra_arg(name);
 
@@ -351,6 +368,7 @@ void concrete_option_set::from_command_l
           name = "--";
           o = getopt(by_name, name);
           arg = idx(args,i);
+          is_cancel = false;
         }
 
       if (allow_xargs && (name == "xargs" || name == "@"))
@@ -373,8 +391,16 @@ void concrete_option_set::from_command_l
             ++i;
           try
             {
-              if (o.setter)
-                o.setter(arg());
+              if (!is_cancel)
+                {
+                  if (o.setter)
+                    o.setter(arg());
+                }
+              else
+                {
+                  if (o.resetter)
+                    o.resetter();
+                }
             }
           catch (boost::bad_lexical_cast)
             {
@@ -423,7 +449,7 @@ void concrete_option_set::from_key_value
 }
 
 // Get the non-description part of the usage string,
-// looks like "--long [ -s ] <arg>".
+// looks like "--long [ -s ] <arg> / --cancel".
 static string usagestr(concrete_option const & opt)
 {
   string out;
@@ -435,8 +461,17 @@ static string usagestr(concrete_option c
     out = "--" + opt.longname;
   else if (!opt.shortname.empty())
     out = "-" + opt.shortname;
-  else
-    return "";
+
+  if (out.empty())
+    return out;
+
+  if (!opt.cancelname.empty())
+    {
+      if (!out.empty())
+        out += " / ";
+      out += "--" + opt.cancelname;
+    }
+
   if (opt.has_arg)
     return out + " <arg>";
   else
============================================================
--- option.hh	a120f75cc822a8ff7a0e0602d2385f3d730f2588
+++ option.hh	4b8b3b06e05e716358a3da600f0c0a948104af8c
@@ -78,7 +78,7 @@ namespace option {
   };
 
   // Split a "long,s" option name into long and short names.
-  void splitname(char const * from, std::string & name, std::string & n);
+  void splitname(char const * from, std::string & name, std::string & n, std::string & cancelname);
 
   // An option that can be set and reset.
   struct concrete_option
@@ -86,6 +86,7 @@ namespace option {
     char const * description;
     std::string longname;
     std::string shortname;
+    std::string cancelname;
     bool has_arg;
     boost::function<void (std::string)> setter;
     boost::function<void ()> resetter;
@@ -246,7 +247,7 @@ namespace option {
     {
       concrete_option out;
       out.description = description;
-      splitname(names, out.longname, out.shortname);
+      splitname(names, out.longname, out.shortname, out.cancelname);
       out.has_arg = has_arg;
 
       if (setter)