From 6b9fc98fc8e7d334ce078279d3133b22aeabbc44 Mon Sep 17 00:00:00 2001
From: Ray Speth <speth@mit.edu>
Date: Tue, 5 Mar 2013 17:02:47 +0000
Subject: [PATCH] [1D] Pruning may not remove adjacent grid points

---
 src/oneD/refine.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/oneD/refine.cpp b/src/oneD/refine.cpp
index 63800cb53..042b2dac0 100644
--- a/src/oneD/refine.cpp
+++ b/src/oneD/refine.cpp
@@ -151,6 +151,14 @@ int Refiner::analyze(size_t n, const doublereal* z,
         }
     }
 
+    // Don't allow pruning to remove multiple adjacent grid points
+    // in a single pass.
+    for (size_t j = 2; j < n-1; j++) {
+        if (m_keep[j] == -1 && m_keep[j-1] == -1) {
+            m_keep[j] = 1;
+        }
+    }
+
     return int(m_loc.size());
 }