Columns: Removed _fixed_width for indicator columns

- Column indicator formats (depends.indicator, for example), should not set the
  ::_fixed_width flag because then the column does not have the opportunity to
  be suppressed via rc.print.empty.colums=1.

src/columns/ColDepends.cpp

@@ -83,8 +83,10 @@ void ColumnDepends::measure (Task& task, unsigned int& minimum, unsigned int& ma
 
   if (_style == "indicator")
   {
+    if (task.has ("depends"))
       minimum = maximum = utf8_width (context.config.get ("dependency.indicator"));
-    _fixed_width = true;
+    else
+      minimum = maximum = 0;
   }
   else if (_style == "count")
   {

src/columns/ColRecur.cpp

@@ -86,8 +86,10 @@ void ColumnRecur::measure (Task& task, unsigned int& minimum, unsigned int& maxi
     }
     else if (_style == "indicator")
     {
+      if (task.has ("recur"))
         minimum = maximum = utf8_width (context.config.get ("recurrence.indicator"));
-      _fixed_width = true;
+      else
+        minimum = maximum = 0;
     }
     else
       throw format (STRING_COLUMN_BAD_FORMAT, _name, _style);

src/columns/ColStart.cpp

@@ -74,8 +74,10 @@ void ColumnStart::measure (Task& task, unsigned int& minimum, unsigned int& maxi
   {
     if (_style == "active")
     {
+      if (task.has ("start"))
         minimum = maximum = utf8_width (context.config.get ("active.indicator"));
-      _fixed_width = true;
+      else
+        minimum = maximum = 0;
     }
     else
       ColumnDate::measure (task, minimum, maximum);

src/columns/ColTags.cpp

@@ -85,8 +85,10 @@ void ColumnTags::measure (Task& task, unsigned int& minimum, unsigned int& maxim
   {
     if (_style == "indicator")
     {
+      if (task.has ("tags"))
         minimum = maximum = utf8_width (context.config.get ("tag.indicator"));
-      _fixed_width = true;
+      else
+        minimum = maximum = 0;
     }
     else if (_style == "count")
     {

src/columns/ColUDA.cpp

@@ -116,8 +116,10 @@ void ColumnUDA::measure (Task& task, unsigned int& minimum, unsigned int& maximu
     }
     else if (_style == "indicator")
     {
+      if (task.has (_name))
         minimum = maximum = utf8_width (context.config.get ("uda." + _name + ".indicator"));
-      _fixed_width = true;
+      else
+        minimum = maximum = 0;
     }
     else
       throw format (STRING_COLUMN_BAD_FORMAT, _name, _style);

src/columns/Column.h

@@ -52,7 +52,7 @@ public:
   const std::string& type () const            { return _type;        }
   bool modifiable () const                    { return _modifiable;  }
   bool is_uda () const                        { return _uda;         }
-  bool is_fixed_width () const                { return _fixed_width;}
+  bool is_fixed_width () const                { return _fixed_width; }
   std::vector <std::string> styles () const   { return _styles;      }
   std::vector <std::string> examples () const { return _examples;    }