Bug Fixes - autofilter

- Auto filter now only creates a filter for read-only commands.
- Fixed bug whereby ambiguities were reported twice:
    "could be one of a, b, a, b".

src/Att.cpp

@@ -259,7 +259,6 @@ bool Att::validNameValue (
 
     std::string combined;
     join (combined, ", ", matches);
-    error += combined;
 
     throw error + combined;
   }

src/Context.cpp

@@ -463,11 +463,12 @@ std::cout << "# parse post-termination description '" << *arg << "'"
   if (descCandidate != "" && noVerticalSpace (descCandidate))
     task.set ("description", descCandidate);
 
-  // TODO task.validate ()
-  // TODO if readOnlyCommand (cmd.command) then any attributes are allowed
-  // TODO if writeCommand (cmd.command) then only modifiable attributes are allowed
+  // TODO task.validate () ?
 
-  constructFilter ();
+  // Read-only command (reports, status, info ...) use filters.  Write commands
+  // (add, done ...) do not.
+  if (cmd.isReadOnlyCommand ())
+    autoFilter ();
 
   // If no command was specified, and there were no command line arguments
   // then invoke the default command.
@@ -490,7 +491,7 @@ std::cout << "# parse post-termination description '" << *arg << "'"
 
 ////////////////////////////////////////////////////////////////////////////////
 // Add all the attributes in the task to the filter.  All except uuid.
-void Context::constructFilter ()
+void Context::autoFilter ()
 {
   foreach (att, task)
   {

src/Context.h

@@ -58,7 +58,7 @@ public:
 private:
   void loadCorrectConfigFile ();
   void parse ();
-  void constructFilter ();
+  void autoFilter ();
 
 public:
   Config                    config;