From 185018b2c8ccafd2602087a4e21f746e0616510f Mon Sep 17 00:00:00 2001
From: Nehal J Wani <nehaljw.kkd1@gmail.com>
Date: Tue, 11 Dec 2018 16:19:55 -0600
Subject: [PATCH 1/2] _marching_cubes_lewiner_cy: mark char as signed

xref: https://github.com/scikit-image/scikit-image/issues/2982
---
 skimage/measure/_marching_cubes_lewiner_cy.pyx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/skimage/measure/_marching_cubes_lewiner_cy.pyx b/skimage/measure/_marching_cubes_lewiner_cy.pyx
index 502d29a..47c11d9 100644
--- a/skimage/measure/_marching_cubes_lewiner_cy.pyx
+++ b/skimage/measure/_marching_cubes_lewiner_cy.pyx
@@ -748,7 +748,7 @@ cdef class Lut:
     This class defines functions to look up values using 1, 2 or 3 indices.
     """ 
     
-    cdef char* VALUES
+    cdef signed char* VALUES
     cdef int L0 # Length
     cdef int L1 # size of tuple
     cdef int L2 # size of tuple in tuple (if any)
@@ -769,7 +769,7 @@ cdef class Lut:
         array = array.ravel()
         cdef int n, N
         N = self.L0 * self.L1 * self.L2
-        self.VALUES = <char *> malloc(N * sizeof(char)) 
+        self.VALUES = <signed char *> malloc(N * sizeof(signed char))
         for n in range(N):
             self.VALUES[n] = array[n]
     
-- 
2.19.1

