Bug #1022

- Fixed bug #1022, where dependencies were note released when a blocking task
  was completed (thanks to Arkady Grudzinsky).
- The Task object now caches ::is_blocked and ::is_blocking Booleans that are
  determined on pending.data load.
- Simplified and sped up color rule processing using cached values, reducing
  the number of map lookups, and removed loop invariants when the rules are
  not defined.
- Simplified urgency calculations given the cached values for blocked/blocking.
- On load, pending.data is scanned for accurate blocked/blocking status
  determination.
- Obsoleted and removed complex single-task dependency calculations.
- Sped up 'nag' processing by using cached values..
- Modified the 'show' command to consider color.blocking to be valid.
- Added default config value for color.blocking, and included it in the
  precedence list ahead of blocked, as it is more important.
- Updated taskrc.5 man page to include the new color.blocking rule, and its
  place in the rule precedence.

src/Task.cpp

@@ -100,6 +100,8 @@ Task::Task ()
 : id (0)
 , urgency_value (0.0)
 , recalc_urgency (true)
+, is_blocked (false)
+, is_blocking (false)
 {
 }
 
@@ -119,6 +121,8 @@ Task& Task::operator= (const Task& other)
     id             = other.id;
     urgency_value  = other.urgency_value;
     recalc_urgency = other.recalc_urgency;
+    is_blocked     = other.is_blocked;
+    is_blocking    = other.is_blocking;
   }
 
   return *this;
@@ -1409,22 +1413,8 @@ float Task::urgency_waiting () const
 // A task is blocked only if the task it depends upon is pending/waiting.
 float Task::urgency_blocked () const
 {
-  if (has ("depends"))
-  {
-    std::vector <std::string> deps;
-    getDependencies (deps);
-
-    std::vector <std::string>::iterator d;
-    for (d = deps.begin (); d != deps.end (); ++d)
-    {
-      Task t;
-      if (context.tdb2.get (*d, t) &&
-          (t.getStatus () == Task::pending || t.getStatus () == Task::waiting))
-      {
-        return 1.0;
-      }
-    }
-  }
+  if (is_blocked)
+    return 1.0;
 
   return 0.0;
 }
@@ -1524,7 +1514,7 @@ float Task::urgency_age () const
 ////////////////////////////////////////////////////////////////////////////////
 float Task::urgency_blocking () const
 {
-  if (dependencyIsBlocking (*this))
+  if (is_blocking)
     return 1.0;
 
   return 0.0;