gridGenXvals/gridGenYvals: recheck xinc/yinc if fi(xfirst+(size-1)*inc) > last

src/grid.c

@@ -3,6 +3,7 @@
 #endif
 
 #include <string.h>
+#include <float.h>  /* FLT_EPSILON */
 
 #ifdef USE_MPI
 #include <mpi.h>
@@ -210,22 +211,27 @@ int gridSize(void)
 
 void gridGenXvals(int xsize, double xfirst, double xlast, double xinc, double *xvals)
 {
-  long i;
-
-  if ( (! (fabs(xinc) > 0)) && xsize > 1 )
+  if ( xsize > 1 )
     {
-      if ( xfirst >= xlast )
+      if ( (fabs(xinc) > 0) && (xlast > xfirst) && (fabs(xinc*1000 - NINT(xinc*1000)) <= FLT_EPSILON) )
         {
-          while ( xfirst >= xlast ) xlast += 360;
-          xinc = (xlast-xfirst)/(xsize);
+          if ( (xfirst + (xsize-1)*xinc) > xlast ) xinc = (xlast-xfirst)/(xsize-1);
         }
       else
         {
-          xinc = (xlast-xfirst)/(xsize-1);
+          if ( xfirst >= xlast )
+            {
+              while ( xfirst >= xlast ) xlast += 360;
+              xinc = (xlast-xfirst)/(xsize);
+            }
+          else
+            {
+              xinc = (xlast-xfirst)/(xsize-1);
+            }
         }
     }
 
-  for ( i = 0; i < xsize; i++ )
+  for ( int i = 0; i < xsize; ++i )
     xvals[i] = xfirst + i*xinc;
 }
 
@@ -311,9 +317,13 @@ void gridGenYvals(int gridtype, int ysize, double yfirst, double ylast, double y
         }
     }
   /*     else if ( gridtype == GRID_LONLAT || gridtype == GRID_GENERIC ) */
-  else
+  else if ( ysize > 1 )
     {
-      if ( (! (fabs(yinc) > 0)) && ysize > 1 )
+      if ( (fabs(yinc) > 0) && (fabs(yinc*1000 - NINT(yinc*1000)) <= FLT_EPSILON) )
+        {
+          if ( (yfirst + (ysize-1)*yinc) > ylast ) yinc = (ylast-yfirst)/(ysize-1);
+        }
+      else
         {
           if ( IS_EQUAL(yfirst, ylast) && IS_NOT_EQUAL(yfirst, 0) ) ylast *= -1;