From 5313dbc6bf9cac80e59adba7e6d203394217b825 Mon Sep 17 00:00:00 2001
From: Paul Beckingham <paul@beckingham.net>
Date: Fri, 22 Apr 2016 00:16:42 -0400
Subject: [PATCH] helper: Fixed bug that lost results when no ranges were
 subtracted from another range

---
 src/helper.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/helper.cpp b/src/helper.cpp
index 8feacde0..fbb4e4e6 100644
--- a/src/helper.cpp
+++ b/src/helper.cpp
@@ -447,8 +447,10 @@ std::vector <Daterange> subtractRanges (
   const std::vector <Daterange>& ranges,
   const std::vector <Daterange>& subtractions)
 {
-  std::vector <Daterange> results;
+  if (! subtractions.size ())
+    return ranges;
 
+  std::vector <Daterange> results;
   for (auto& r1 : ranges)
     for (auto& r2 : subtractions)
       for (auto& r3 : r1.subtract (r2))