Fix stupid iteration bug.

Iteration would terminate at ID size() rather than capacity(),
where size() is the number of allocated entities. Depending on where
deleted entities were, this would likely miss entities at the end of
the allocated vectors.

Fixes #10.

2 files changed, 26 insertions, 2 deletions

diff --git a/entityx/Entity.h b/entityx/Entity.h
index abb3552..28c1b5d 100644
--- a/entityx/Entity.h
+++ b/entityx/Entity.h
@@ -302,6 +302,7 @@ class EntityManager : boost::noncopyable, public enable_shared_from_this<EntityM
         while (i_ < capacity_ && !predicate()) {
           ++i_;
         }
+
         if (i_ < capacity_ && !unpackers_.empty()) {
           Entity::Id id = manager_->create_id(i_);
           for (auto &unpacker : unpackers_) {
@@ -333,9 +334,9 @@ class EntityManager : boost::noncopyable, public enable_shared_from_this<EntityM
     }
 
     Iterator begin() { return Iterator(manager_, predicates_, unpackers_, 0); }
-    Iterator end() { return Iterator(manager_, predicates_, unpackers_, manager_->size()); }
+    Iterator end() { return Iterator(manager_, predicates_, unpackers_, manager_->capacity()); }
     const Iterator begin() const { return Iterator(manager_, predicates_, unpackers_, 0); }
-    const Iterator end() const { return Iterator(manager_, predicates_, unpackers_, manager_->size()); }
+    const Iterator end() const { return Iterator(manager_, predicates_, unpackers_, manager_->capacity()); }
 
     template <typename A>
     View &unpack_to(ptr<A> &a) {
diff --git a/entityx/Entity_test.cc b/entityx/Entity_test.cc
index 701c15b..bdc217b 100644
--- a/entityx/Entity_test.cc
+++ b/entityx/Entity_test.cc
@@ -8,6 +8,7 @@
  * Author: Alec Thomas <alec@swapoff.org>
  */
 
+#include <algorithm>
 #include <iterator>
 #include <string>
 #include <utility>
@@ -369,3 +370,25 @@ TEST_F(EntityManagerTest, TestEntityDestroyAll) {
   ASSERT_FALSE(a.valid());
   ASSERT_FALSE(b.valid());
 }
+
+
+TEST_F(EntityManagerTest, TestEntityDestroyHole) {
+  std::vector<Entity> entities;
+
+  auto count = [this]() {
+    auto e = em->entities_with_components<Position>();
+    return std::count_if(e.begin(), e.end(), [] (const Entity &) { return true; });
+  };
+
+  for (int i = 0; i < 5000; i++) {
+    auto e = em->create();
+    e.assign<Position>();
+    entities.push_back(e);
+  }
+
+  ASSERT_EQ(count(), 5000);
+
+  entities[2500].destroy();
+
+  ASSERT_EQ(count(), 4999);
+}