Bug #892

- Possible fix for bug #892, which I cannot replicate anyway.  This fix
  involves testing my suspicion that std::map autovivifies via
  std::map::operator[], which is not nice.  Will ask Dmitriy to confirm.

src/A3.cpp

@@ -1292,9 +1292,9 @@ bool A3::is_attr (Nibbler& n, Arg& arg)
         // therefore not stored.
 
         // I suspect this is auto-vivifying context.columns["limit"].  Bugger.
-        Column* col = context.columns[name];
-        if (col)
-          arg._type = Arg::type_id (col->type ());
+        std::map<std::string, Column*>::iterator i = context.columns.find (name);
+        if (i != context.columns.end ())
+          arg._type = Arg::type_id (i->second->type ());
         else
           arg._type = Arg::type_pseudo;
 

src/columns/Column.cpp

@@ -25,7 +25,6 @@
 //
 ////////////////////////////////////////////////////////////////////////////////
 
-
 #define L10N                                           // Localization complete.
 
 #include <Context.h>