Enhancement - Supports '--' on the command line

- Using '--' on the command line separates the left hand side, where
  task is free to interpret arguments in the usual way, and the right
  hand side, which is then assumed to be part of the task description,
  and is not interpreted by task.

src/parse.cpp

@@ -478,6 +478,7 @@ void parse (
 {
   command = "";
 
+  bool terminated = false;
   bool foundSequence = false;
   bool foundSomethingAfterSequence = false;
 
@@ -490,87 +491,104 @@ void parse (
     // specified rc file.
     if (arg.substr (0, 3) != "rc:")
     {
-      size_t colon;               // Pointer to colon in argument.
-      std::string from;
-      std::string to;
-      bool global;
-      std::vector <int> sequence;
-
-      // An id is the first argument found that contains all digits.
-      if (lowerCase (command) != "add"  && // "add" doesn't require an ID
-          validSequence (arg, sequence) &&
-          ! foundSomethingAfterSequence)
+      if (!terminated)
       {
-        foundSequence = true;
-        foreach (id, sequence)
-          task.addId (*id);
-      }
+        size_t colon;               // Pointer to colon in argument.
+        std::string from;
+        std::string to;
+        bool global;
+        std::vector <int> sequence;
 
-      // Tags begin with + or - and contain arbitrary text.
-      else if (validTag (arg))
-      {
-        if (foundSequence)
-          foundSomethingAfterSequence = true;
+        // The '--' argument shuts off all parsing - everything is an argument.
+        if (arg == "--")
+          terminated = true;
 
-        if (arg[0] == '+')
-          task.addTag (arg.substr (1, std::string::npos));
-        else if (arg[0] == '-')
-          task.addRemoveTag (arg.substr (1, std::string::npos));
-      }
-
-      // Attributes contain a constant string followed by a colon, followed by a
-      // value.
-      else if ((colon = arg.find (":")) != std::string::npos)
-      {
-        if (foundSequence)
-          foundSomethingAfterSequence = true;
-
-        std::string name  = lowerCase (arg.substr (0, colon));
-        std::string value = arg.substr (colon + 1, std::string::npos);
-
-        if (validAttribute (name, value, conf))
+        // An id is the first argument found that contains all digits.
+        else if (lowerCase (command) != "add"  && // "add" doesn't require an ID
+            validSequence (arg, sequence) &&
+            ! foundSomethingAfterSequence)
         {
-          if (name != "recur" || validDuration (value))
-            task.setAttribute (name, value);
+          foundSequence = true;
+          foreach (id, sequence)
+            task.addId (*id);
         }
 
-        // If it is not a valid attribute, then allow the argument as part of
-        // the description.
+        // Tags begin with + or - and contain arbitrary text.
+        else if (validTag (arg))
+        {
+          if (foundSequence)
+            foundSomethingAfterSequence = true;
+
+          if (arg[0] == '+')
+            task.addTag (arg.substr (1, std::string::npos));
+          else if (arg[0] == '-')
+            task.addRemoveTag (arg.substr (1, std::string::npos));
+        }
+
+        // Attributes contain a constant string followed by a colon, followed by a
+        // value.
+        else if ((colon = arg.find (":")) != std::string::npos)
+        {
+          if (foundSequence)
+            foundSomethingAfterSequence = true;
+
+          std::string name  = lowerCase (arg.substr (0, colon));
+          std::string value = arg.substr (colon + 1, std::string::npos);
+
+          if (validAttribute (name, value, conf))
+          {
+            if (name != "recur" || validDuration (value))
+              task.setAttribute (name, value);
+          }
+
+          // If it is not a valid attribute, then allow the argument as part of
+          // the description.
+          else
+          {
+            if (descCandidate.length ())
+              descCandidate += " ";
+            descCandidate += arg;
+          }
+        }
+
+        // Substitution of description text.
+        else if (validSubstitution (arg, from, to, global))
+        {
+          if (foundSequence)
+            foundSomethingAfterSequence = true;
+
+          task.setSubstitution (from, to, global);
+        }
+
+        // Command.
+        else if (command == "")
+        {
+          if (foundSequence)
+            foundSomethingAfterSequence = true;
+
+          std::string l = lowerCase (arg);
+          if (isCommand (l) && validCommand (l))
+            command = l;
+          else
+          {
+            if (descCandidate.length ())
+              descCandidate += " ";
+            descCandidate += arg;
+          }
+        }
+
+        // Anything else is just considered description.
         else
         {
+          if (foundSequence)
+            foundSomethingAfterSequence = true;
+
           if (descCandidate.length ())
             descCandidate += " ";
           descCandidate += arg;
         }
       }
-
-      // Substitution of description text.
-      else if (validSubstitution (arg, from, to, global))
-      {
-        if (foundSequence)
-          foundSomethingAfterSequence = true;
-
-        task.setSubstitution (from, to, global);
-      }
-
-      // Command.
-      else if (command == "")
-      {
-        if (foundSequence)
-          foundSomethingAfterSequence = true;
-
-        std::string l = lowerCase (arg);
-        if (isCommand (l) && validCommand (l))
-          command = l;
-        else
-        {
-          if (descCandidate.length ())
-            descCandidate += " ";
-          descCandidate += arg;
-        }
-      }
-
-      // Anything else is just considered description.
+      // terminated, therefore everything subsequently is a description.
       else
       {
         if (foundSequence)