From 7a87e395c4afcc678493cd250cf1c535586723dd Mon Sep 17 00:00:00 2001
From: josh <josh@45c1a28c-8058-47b2-ae61-ca45b979098e>
Date: Mon, 8 Dec 2008 23:29:48 +0000
Subject: [PATCH] avoid segfault when num_pixels is not an even multiple of
 task_size

git-svn-id: svn://anubis/gvsu@346 45c1a28c-8058-47b2-ae61-ca45b979098e
---
 cs677/final/mpi-fractals.cc | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/cs677/final/mpi-fractals.cc b/cs677/final/mpi-fractals.cc
index e62af76..d560166 100644
--- a/cs677/final/mpi-fractals.cc
+++ b/cs677/final/mpi-fractals.cc
@@ -341,7 +341,11 @@ void draw(int rank, int world_size, int nprocs, int width, int height,
                 MPI_Send(&done_val, 1, MPI_INT,
                     mpi_status.MPI_SOURCE, 0, MPI_COMM_WORLD);
             }
-            memcpy(pixels + taskVals[0], taskVals + 1, task_size * sizeof(int));
+            int num_to_copy = task_size;
+            if (taskVals[0] + num_to_copy > num_pixels)
+                num_to_copy = num_pixels - taskVals[0];
+            memcpy(pixels + taskVals[0], taskVals + 1,
+                num_to_copy * sizeof(int));
         }
     }
     else