Feature: Error on virtual tag modification attempt

- An attempt to add or remove a virtual tag is now an error (thanks to Scott M).

ChangeLog

@@ -24,7 +24,7 @@
   and enabling more flexible use of the function.
 - Enable "task sync" support by default.  "cmake -DENABLE_SYNC=OFF" allows
   disabling it and building Taskwarrior without libgnutls available.
-
+- An attempt to add or remove a virtual tag is now an error (thanks to Scott M).
 
 ------ current release ---------------------------
 

NEWS

@@ -2,6 +2,7 @@
 New Features in Taskwarrior 2.4.5
 
   - The active context, if one is set, is now identified in "task context list"
+  - It is an error to attempt and add or remove of a virtual tag.
 
 New commands in Taskwarrior 2.4.5
 

doc/man/task.1.in

@@ -504,9 +504,10 @@ Shows a report of aggregated task status by project.
 
 .TP
 .B task <filter> tags
-Show a list of all tags used.  Any special tags used are highlighted.  Note that
+Show a list of all tags used. Any special tags used are highlighted. Note that
 virtual tags are not listed - they don't really exist, and are just a convenient
-notation for other task metadata.
+notation for other task metadata. It is an error to attempt to add or remove a
+virtual tag.
 
 .TP
 .B task timesheet [weeks]
@@ -666,7 +667,8 @@ are:
     DELETED      Matches if the task has deleted status
 
 You can use +BLOCKED to filter blocked tasks, or -BLOCKED for unblocked tasks.
-Similarly, -BLOCKED is equivalent to +UNBLOCKED.
+Similarly, -BLOCKED is equivalent to +UNBLOCKED. It is an error to attempt to
+add or remove a virtual tag.
 
 .TP
 .B project:<project-name>

src/Task.cpp

@@ -1092,6 +1092,7 @@ bool Task::hasTag (const std::string& tag) const
 {
   // Synthetic tags - dynamically generated, but do not occupy storage space.
   // Note: This list must match that in CmdInfo::execute.
+  // Note: This list must match that in ::feedback_reserved_tags.
   if (tag == "BLOCKED")   return is_blocked;
   if (tag == "UNBLOCKED") return !is_blocked;
   if (tag == "BLOCKING")  return is_blocking;
@@ -2094,11 +2095,13 @@ void Task::modify (modType type, bool text_required /* = false */)
       else if (a._lextype == Lexer::Type::tag)
       {
         std::string tag = a.attribute ("name");
+        feedback_reserved_tags (tag);
+
         if (a.attribute ("sign") == "+")
         {
           context.debug (label + "tags <-- add '" + tag + "'");
           addTag (tag);
-          feedback_special_tags ((*this), tag);
+          feedback_special_tags (*this, tag);
         }
         else
         {

src/commands/CmdInfo.cpp

@@ -303,6 +303,7 @@ int CmdInfo::execute (std::string& output)
     // Virtual tags.
     {
       // Note: This list must match that in Task::hasTag.
+      // Note: This list must match that in ::feedback_reserved_tags.
       std::string virtualTags = "";
       if (task.hasTag ("ACTIVE"))    virtualTags += "ACTIVE ";
       if (task.hasTag ("ANNOTATED")) virtualTags += "ANNOTATED ";

src/feedback.cpp

@@ -351,6 +351,41 @@ void feedback_affected (const std::string& effect, const Task& task)
   }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// Implements feedback and error when adding a reserved tag name.
+void feedback_reserved_tags (const std::string& tag)
+{
+  // Note: This list must match that in Task::hasTag.
+  // Note: This list must match that in CmdInfo::execute.
+  if (tag == "BLOCKED"   ||
+      tag == "UNBLOCKED" ||
+      tag == "BLOCKING"  ||
+      tag == "READY"     ||
+      tag == "DUE"       ||
+      tag == "DUETODAY"  ||
+      tag == "TODAY"     ||
+      tag == "YESTERDAY" ||
+      tag == "TOMORROW"  ||
+      tag == "OVERDUE"   ||
+      tag == "WEEK"      ||
+      tag == "MONTH"     ||
+      tag == "YEAR"      ||
+      tag == "ACTIVE"    ||
+      tag == "SCHEDULED" ||
+      tag == "CHILD"     ||
+      tag == "UNTIL"     ||
+      tag == "ANNOTATED" ||
+      tag == "TAGGED"    ||
+      tag == "PARENT"    ||
+      tag == "WAITING"   ||
+      tag == "PENDING"   ||
+      tag == "COMPLETED" ||
+      tag == "DELETED")
+  {
+    throw format (STRING_FEEDBACK_TAG_VIRTUAL, tag);
+  }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Implements feedback when adding special tags to a task.
 void feedback_special_tags (const Task& task, const std::string& tag)

src/l10n/deu-DEU.h

@@ -792,6 +792,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "Das besondere Schlagwort 'nonag' verhindert Nachfragen, wenn diese Aufgabe geändert wird."
 #define STRING_FEEDBACK_TAG_NOCAL    "Das besondere Schlagwort 'nocal' verhindert, dass diese Aufgabe im 'calendar'-Report erscheint."
 #define STRING_FEEDBACK_TAG_NEXT     "Das besondere Schlagwort 'next' erhöht die Dringlichkeit dieser Aufgabe, sodass sie im 'next'-Report erscheint."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Aufgabe {1} '{2}' entsperrt."
 #define STRING_FEEDBACK_EXPIRED      "Aufgabe {1} '{2}' ist abgelaufen und wurde gelöscht."
 #define STRING_FEEDBACK_BACKLOG      "Lokale Änderungen.  Datenabgleich erforderlich."

src/l10n/eng-USA.h

@@ -792,6 +792,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "The 'nonag' special tag will prevent nagging when this task is modified."
 #define STRING_FEEDBACK_TAG_NOCAL    "The 'nocal' special tag will keep this task off the 'calendar' report."
 #define STRING_FEEDBACK_TAG_NEXT     "The 'next' special tag will boost the urgency of this task so it appears on the 'next' report."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Unblocked {1} '{2}'."
 #define STRING_FEEDBACK_EXPIRED      "Task {1} '{2}' expired and was deleted."
 #define STRING_FEEDBACK_BACKLOG      "There are local changes.  Sync required."

src/l10n/epo-RUS.h

@@ -792,6 +792,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "Speciala etikedo 'nonag' antaŭmalebligitos molestojn, kiam oni modifus tiun taskon."
 #define STRING_FEEDBACK_TAG_NOCAL    "Speciala etikedo 'nocal' ekskluzivos tiun taskon ĉe raporto 'calendar'."
 #define STRING_FEEDBACK_TAG_NEXT     "Speciala etikedo 'next' pligrandigos la urĝecon de tiu tasko por ke ĝi aperus ĉe raporto 'next'."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Malblokis {1} '{2}'."
 #define STRING_FEEDBACK_EXPIRED      "Tasko {1} '{2}' fortempiĝis do estis viŝata."
 #define STRING_FEEDBACK_BACKLOG      "Estas lokaj ŝanĝoj. Sinkronigo devita."

src/l10n/esp-ESP.h

@@ -804,6 +804,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "La marca especial 'nonag' evitará el recuerdo fastidioso cuando la tarea sea modificada."
 #define STRING_FEEDBACK_TAG_NOCAL    "La marca especial 'nocal' mantendrá esta tarea fuera del informe 'calendar'."
 #define STRING_FEEDBACK_TAG_NEXT     "La etiqueta especial 'next' aumentará la urgencia de esta tarea para que aparezca en el informe 'next'."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Desbloqueada {1} '{2}'."
 #define STRING_FEEDBACK_EXPIRED      "La tarea {1} '{2}' caducó y fue eliminada."
 #define STRING_FEEDBACK_BACKLOG      "Hay modificaciones locales.  Se require una sincronización."

src/l10n/fra-FRA.h

@@ -792,6 +792,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "The 'nonag' special tag will prevent nagging when this task is modified."
 #define STRING_FEEDBACK_TAG_NOCAL    "The 'nocal' special tag will keep this task off the 'calendar' report."
 #define STRING_FEEDBACK_TAG_NEXT     "The 'next' special tag will boost the urgency of this task so it appears on the 'next' report."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Unblocked {1} '{2}'."
 #define STRING_FEEDBACK_EXPIRED      "Tâche {1} '{2}' a expiré et a été supprimée."
 #define STRING_FEEDBACK_BACKLOG      "Il y a des changements locaux.  Synchronisation requise."

src/l10n/ita-ITA.h

@@ -791,6 +791,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "Il tag speciale 'nonag' eviterà problemi quando il task è modificato."
 #define STRING_FEEDBACK_TAG_NOCAL    "Il tag speciale 'nocal' manterrà il task fuori dal report 'calendar'."
 #define STRING_FEEDBACK_TAG_NEXT     "Il tag speciale 'next' aumenterà l'urgenza di questo task in modo che appaia nel report 'next'."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Sbloccato {1} '{2}'."
 #define STRING_FEEDBACK_EXPIRED      "Il task {1} '{2}' è scaduto ed è stato eliminato"
 #define STRING_FEEDBACK_BACKLOG      "There are local changes.  Sync required."

src/l10n/jpn-JPN.h

@@ -792,6 +792,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "The 'nonag' special tag will prevent nagging when this task is modified."
 #define STRING_FEEDBACK_TAG_NOCAL    "The 'nocal' special tag will keep this task off the 'calendar' report."
 #define STRING_FEEDBACK_TAG_NEXT     "The 'next' special tag will boost the urgency of this task so it appears on the 'next' report."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Unblocked {1} '{2}'."
 #define STRING_FEEDBACK_EXPIRED      "Task {1} '{2}' expired and was deleted."
 #define STRING_FEEDBACK_BACKLOG      "There are local changes.  Sync required."

src/l10n/pol-POL.h

@@ -792,6 +792,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "Specjalny tag 'nonag' uchroni przed upierdliwością kiedy zadanie jest modyfikowane."
 #define STRING_FEEDBACK_TAG_NOCAL    "Specjalny tag 'nocal' spowoduje nie dodawanie zadania do kalendarza."
 #define STRING_FEEDBACK_TAG_NEXT     "Specjalny tag 'next' podniesie pilność tego zadania co spowoduje wyświetlenie go w raporcie 'next'."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Odblokowane {1} '{2}'."
 #define STRING_FEEDBACK_EXPIRED      "Zadanie {1} '{2}' jest przedawnione i zostało usunięte."
 #define STRING_FEEDBACK_BACKLOG      "Wykryto lokalne zmiany. Wymagana synchronizacja."

src/l10n/por-PRT.h

@@ -792,6 +792,7 @@
 #define STRING_FEEDBACK_TAG_NONAG    "A marca especial 'nonag' irá prevenir avisos quando a tarefa é modificada."
 #define STRING_FEEDBACK_TAG_NOCAL    "A marca especial 'nocal' irá manter esta tarefa ausente do relatório de 'calendário'."
 #define STRING_FEEDBACK_TAG_NEXT     "A marca especial 'next' irá aumentar a urgência desta tarefa de modo a que apareça no relatório 'next'."
+#define STRING_FEEDBACK_TAG_VIRTUAL  "Virtual tags (including '{1}') are reserved and may not be added or removed."
 #define STRING_FEEDBACK_UNBLOCKED    "Desbloqueada {1} '{2}'."
 #define STRING_FEEDBACK_EXPIRED      "Tarefa {1} '{2}' expirou e foi eliminada."
 #define STRING_FEEDBACK_BACKLOG      "Há modificações locais. Necessário sincronizar (sync)."

src/main.h

@@ -67,6 +67,7 @@ std::string renderAttribute (const std::string&, const std::string&, const std::
 void feedback_affected (const std::string&);
 void feedback_affected (const std::string&, int);
 void feedback_affected (const std::string&, const Task&);
+void feedback_reserved_tags (const std::string&);
 void feedback_special_tags (const Task&, const std::string&);
 void feedback_unblocked (const Task&);
 void feedback_backlog ();