TW-1688: task fails to import

- Thanks to Rainer Müller.

ChangeLog

@@ -150,6 +150,7 @@
           Patrick).
 - TW-1687 task add due:som appears to be interpreted as 'someday' (thanks to
           Alan Young).
+- TW-1688 task fails to import (thanks to Rainer Müller).
 - Prevent potential task duplication during import for non-pending tasks.
 - Show the active context in "context list", if any is active.
 - Fix "task edit" dropping annotation text after newlines.

src/dependency.cpp

@@ -67,15 +67,14 @@ void dependencyGetBlocking (const Task& task, std::vector <Task>& blocking)
 // Returns true if the supplied task adds a cycle to the dependency chain.
 bool dependencyIsCircular (const Task& task)
 {
-  std::stack <Task> s;
-  std::vector <std::string> deps_current;
-
   std::string task_uuid = task.get ("uuid");
 
+  std::stack <Task> s;
   s.push (task);
-  while (!s.empty ())
+  while (! s.empty ())
   {
     Task& current = s.top ();
+    std::vector <std::string> deps_current;
     current.getDependencies (deps_current);
 
     // This is a basic depth first search that always terminates given the
@@ -85,16 +84,18 @@ bool dependencyIsCircular (const Task& task)
     // function, this is a reasonable assumption.
     for (unsigned int i = 0; i < deps_current.size (); i++)
     {
-      context.tdb2.get (deps_current[i], current);
-
-      if (task_uuid == current.get ("uuid"))
+      if (context.tdb2.get (deps_current[i], current))
+      {
+        if (task_uuid == current.get ("uuid"))
         {
           // Cycle found, initial task reached for the second time!
           return true;
         }
 
-      s.push (current);
+        s.push (current);
+      }
     }
+
     s.pop ();
   }
 

test/tw-1688.t

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+. bash_tap_tw.sh
+
+# TW-1688 task fails to import
+#   The problem is when a completed task, with a dependency is exported, then
+#   imported after the data is removed. On import, the circular dependency
+#   check didn't notice that a UUID failed to exist, and generated a JSON error.
+#
+#   Although an unusual circumstance, people do delete data from their
+#   completed.data file.
+
+task add one
+task log two depends:1
+
+JSON=$(mktemp /tmp/tw-1688.XXXXXXXXXX)
+task /two/ export > $JSON
+
+rm $TASKDATA/pending.data $TASKDATA/completed.data
+task import $JSON
+

test/tw-46.t

@@ -42,7 +42,6 @@ class TestBug46(TestCase):
         self.t("add two")
         self.t("add three")
 
-    @unittest.expectedFailure
     def test_bug46(self):
         """Circular dependency detection broken by deletion of completed.data"""
         self.t("1 mod dep:2")