core: turn trip-table into our own sorted_owning_table

Since the sorted_owning_table depends on the fact that
different elements never compare as equal, make the
comparison function safer in that respect. If all failes,
compare the pointers.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/owning_table.h

@@ -140,6 +140,10 @@ public:
 		}
 		return it - this->begin();
 	}
+	// Note: this is silly - finding the pointer by a linear search
+	// is probably significantly faster than doing a binary search.
+	// But it helps finding consistency problems for now. Remove in
+	// due course.
 	pull_result pull(const T *item) {
 		size_t idx = get_idx(item);
 		if (idx == std::string::npos) {
@@ -148,6 +152,9 @@ public:
 		}
 		return { this->pull_at(idx), idx };
 	}
+	void sort() {
+		std::sort(this->begin(), this->end(), [](const auto &a, const auto &b) { return CMP(*a, *b) < 0; });
+	}
 };
 
 #endif