From 65830dd7058b3a0fbb5dbcd67d235b5ada722b09 Mon Sep 17 00:00:00 2001
From: "Dustin J. Mitchell" <dustin@v.igoro.us>
Date: Sat, 18 Dec 2021 02:37:41 +0000
Subject: [PATCH] replace the global contextTask with a Context field

---
 src/Context.h  |  1 +
 src/Eval.cpp   | 18 +++++++++++-------
 src/Filter.cpp | 10 +++-------
 src/Task.cpp   |  4 +---
 4 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/src/Context.h b/src/Context.h
index 06159f6d2..4475f9dc7 100644
--- a/src/Context.h
+++ b/src/Context.h
@@ -129,6 +129,7 @@ public:
 // CurrentTask resets Context::currentTask to NULL on destruction; this ensures
 // that this context value is not a dangling pointer.
 class CurrentTask {
+public:
   ~CurrentTask();
 
 private:
diff --git a/src/Eval.cpp b/src/Eval.cpp
index 40045bafb..5319a0804 100644
--- a/src/Eval.cpp
+++ b/src/Eval.cpp
@@ -35,8 +35,6 @@
 #include <shared.h>
 #include <format.h>
 
-extern Task* contextTask;
-
 ////////////////////////////////////////////////////////////////////////////////
 // Supported operators, borrowed from C++, particularly the precedence.
 // Note: table is sorted by length of operator string, so searches match
@@ -106,7 +104,7 @@ static bool namedConstants (const std::string& name, Variant& value)
 // Support for evaluating DOM references (add with `e.AddSource(domSource)`)
 bool domSource (const std::string& identifier, Variant& value)
 {
-  if (getDOM (identifier, contextTask, value))
+  if (getDOM (identifier, Context::getContext ().currentTask, value))
   {
     value.source (identifier);
     return true;
@@ -292,6 +290,8 @@ void Eval::evaluatePostfixStack (
       Variant left = values.back ();
       values.pop_back ();
 
+      auto contextTask = Context::getContext ().currentTask;
+
       // Ordering these by anticipation frequency of use is a good idea.
       Variant result;
            if (token.first == "and")      result = left && right;
@@ -313,10 +313,14 @@ void Eval::evaluatePostfixStack (
       else if (token.first == "^")        result = left ^ right;
       else if (token.first == "%")        result = left % right;
       else if (token.first == "xor")      result = left.operator_xor (right);
-      else if (token.first == "~")        result = left.operator_match (right, *contextTask);
-      else if (token.first == "!~")       result = left.operator_nomatch (right, *contextTask);
-      else if (token.first == "_hastag_") result = left.operator_hastag (right, *contextTask);
-      else if (token.first == "_notag_")  result = left.operator_notag (right, *contextTask);
+      else if (contextTask) {
+             if (token.first == "~")        result = left.operator_match (right, *contextTask);
+        else if (token.first == "!~")       result = left.operator_nomatch (right, *contextTask);
+        else if (token.first == "_hastag_") result = left.operator_hastag (right, *contextTask);
+        else if (token.first == "_notag_")  result = left.operator_notag (right, *contextTask);
+        else
+          throw format ("Unsupported operator '{1}'.", token.first);
+      }
       else
         throw format ("Unsupported operator '{1}'.", token.first);
 
diff --git a/src/Filter.cpp b/src/Filter.cpp
index 7fb1f963e..15efac912 100644
--- a/src/Filter.cpp
+++ b/src/Filter.cpp
@@ -35,10 +35,6 @@
 #include <format.h>
 #include <shared.h>
 
-////////////////////////////////////////////////////////////////////////////////
-// Context for DOM evaluations
-const Task* contextTask = NULL;
-
 ////////////////////////////////////////////////////////////////////////////////
 // Take an input set of tasks and filter into a subset.
 void Filter::subset (const std::vector <Task>& input, std::vector <Task>& output)
@@ -66,7 +62,7 @@ void Filter::subset (const std::vector <Task>& input, std::vector <Task>& output
     for (auto& task : input)
     {
       // Set up context for any DOM references.
-      contextTask = &task;
+      auto currentTask = Context::getContext ().withCurrentTask(&task);
 
       Variant var;
       eval.evaluateCompiledExpression (var);
@@ -118,7 +114,7 @@ void Filter::subset (std::vector <Task>& output)
     for (auto& task : pending)
     {
       // Set up context for any DOM references.
-      contextTask = &task;
+      auto currentTask = Context::getContext ().withCurrentTask(&task);
 
       Variant var;
       eval.evaluateCompiledExpression (var);
@@ -137,7 +133,7 @@ void Filter::subset (std::vector <Task>& output)
       for (auto& task : completed)
       {
         // Set up context for any DOM references.
-        contextTask = &task;
+        auto currentTask = Context::getContext ().withCurrentTask(&task);
 
         Variant var;
         eval.evaluateCompiledExpression (var);
diff --git a/src/Task.cpp b/src/Task.cpp
index ec81251de..de1507302 100644
--- a/src/Task.cpp
+++ b/src/Task.cpp
@@ -60,8 +60,6 @@
 
 #define APPROACHING_INFINITY 1000   // Close enough.  This isn't rocket surgery.
 
-extern Task* contextTask;
-
 static const float epsilon = 0.000001;
 #endif
 
@@ -2273,7 +2271,7 @@ void Task::modify (modType type, bool text_required /* = false */)
 
   // while reading the parse tree, consider DOM references in the context of
   // this task
-  contextTask = this;
+  auto currentTask = Context::getContext ().withCurrentTask(this);
 
   // Need this for later comparison.
   auto originalStatus = getStatus ();