From 196de2efe3f7d64a165f13fb3627449479bd0220 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Tue, 8 Oct 2019 21:44:33 +0200
Subject: [PATCH] Explicitly bypass resize and memmoves when there is already
 the exact right number of elements available.

---
 Eigen/src/SparseCore/SparseBlock.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Eigen/src/SparseCore/SparseBlock.h b/Eigen/src/SparseCore/SparseBlock.h
index 5ed7c437b..d4535d866 100644
--- a/Eigen/src/SparseCore/SparseBlock.h
+++ b/Eigen/src/SparseCore/SparseBlock.h
@@ -164,7 +164,7 @@ public:
       }
       else
       {
-        if(m_matrix.isCompressed())
+        if(m_matrix.isCompressed() && nnz!=block_size)
         {
           // no need to realloc, simply copy the tail at its respective position and insert tmp
           matrix.data().resize(start + nnz + tail_size);