Avoid division by zero if minimum == maximum of slice to output.

git-svn-id: http://svn.cactuscode.org/arrangements/CactusIO/IOJpeg/trunk@25 eff87b29-5268-4891-90a3-a07138403961

1 files changed, 11 insertions, 1 deletions

diff --git a/src/JPEG.c b/src/JPEG.c
index 588facc..990d9d1 100644
--- a/src/JPEG.c
+++ b/src/JPEG.c
@@ -229,7 +229,17 @@ void AutoColorDataSlice(int nx,int ny, /* size of the image x & y */
   int i,last;
   CCTK_REAL F=(CCTK_REAL)rdfac; /* cast to CCTK_REAL... don't know how the original worked at all without a cast */
   for(i=0,last=nx*ny;i<last;i++,dataout+=3){
-    CCTK_REAL f=bias-(*datain++ - min)/(max-min);
+    CCTK_REAL f;
+
+    /* check for division by 0 */
+    if (min == max)
+    {
+      f = bias;
+    }
+    else
+    {
+      f = bias-(*datain++ - min)/(max-min);
+    }
     /* f-=(max-min); zero-center it */
     /* well it can't be less than 0 */
     if(f>0){