TW-1723: task info causes segfault

- Thanks to Roman Golovin.
- Calls like 'context.columns[name]' autovivify the key 'name' with a default
  ctor value, which ends up polluting the context.columns map with every unique
  attribute name, which is a lot of 'annotation_nnnnnnnnnn' attributes.

ChangeLog

@@ -17,6 +17,7 @@
 - TW-1704 Use Task::identifier to reference the Task in the output
 - TW-1720 CmdContext uses a mix of both throw and std::cout to convey
           errors (thanks to Paul Beckingham).
+- TW-1723 task info causes segfault (thanks to Roman Golovin).
 - Fixed broken build for Cygwin and older GCC (thanks to Richard Boß).
 - The default configuration is now 256-color only.
 - The 'columns' report now shows whether a column is modifiable or read only.

src/Task.cpp

@@ -501,7 +501,6 @@ bool Task::is_dueyear () const
 bool Task::is_udaPresent () const
 {
   for (auto& col : context.columns)
-    if (col.first.compare (0, 11, "annotation_", 11) != 0)
     if (col.second->is_uda () &&
         has (col.first))
       return true;

src/commands/CmdInfo.cpp

@@ -361,9 +361,11 @@ int CmdInfo::execute (std::string& output)
     std::vector <std::string> all = task.all ();
     std::string type;
     for (auto& att: all)
+    {
+      if (context.columns.find (att) != context.columns.end ())
       {
         Column* col = context.columns[att];
-      if (col && col->is_uda ())
+        if (col->is_uda ())
         {
           std::string value = task.get (att);
           if (value != "")
@@ -387,13 +389,14 @@ int CmdInfo::execute (std::string& output)
           }
         }
       }
+    }
 
     // Show any orphaned UDAs, which are identified by not being represented in
     // the context.columns map.
     for (auto& att : all)
     {
       if (att.substr (0, 11) != "annotation_" &&
-          ! context.columns[att])
+          context.columns.find (att) == context.columns.end ())
       {
          row = view.addRow ();
          view.set (row, 0, "[" + att);

src/feedback.cpp

@@ -261,6 +261,8 @@ std::string taskInfoDifferences (
 
 ////////////////////////////////////////////////////////////////////////////////
 std::string renderAttribute (const std::string& name, const std::string& value, const std::string& format /* = "" */)
+{
+  if (context.columns.find (name) != context.columns.end ())
   {
     Column* col = context.columns[name];
     if (col                    &&
@@ -273,6 +275,7 @@ std::string renderAttribute (const std::string& name, const std::string& value,
 
       return d.toString (format);
     }
+  }
 
   return value;
 }