compiler: Fix occurence of NullInterval after rebase

Author: georgebisbas

devito/deprecations.py

@@ -6,14 +6,14 @@ class DevitoDeprecation():
 
     @cached_property
     def coeff_warn(self):
-        warn("The Coefficient API is deprecated and will be removed, coefficients should"
+        warn("The Coefficient API is deprecated and will be removed, coefficients should "
              "be passed directly to the derivative object `u.dx(weights=...)",
              DeprecationWarning, stacklevel=2)
         return
 
     @cached_property
     def symbolic_warn(self):
-        warn("coefficients='symbolic' is deprecated, coefficients should"
+        warn("coefficients='symbolic' is deprecated, coefficients should "
              "be passed directly to the derivative object `u.dx(weights=...)",
              DeprecationWarning, stacklevel=2)
         return

devito/ir/clusters/cluster.py

@@ -393,11 +393,12 @@ def dspace(self):
         # intersecting intervals with matching only dimensions
         for f, v in parts.items():
             for i in v:
-                # oobs check is not required but helps reduce
-                # interval reconstruction
-                if i.dim in oobs and i.dim in f.dimensions:
+                if i.dim in self.ispace and i.dim in f.dimensions:
+                    # oobs check is not required but helps reduce
+                    # interval reconstruction
                     ii = intervals[i.dim].intersection(v[i.dim])
-                    intervals = intervals.set_upper(i.dim, ii.upper)
+                    if not ii.is_Null:
+                        intervals = intervals.set_upper(i.dim, ii.upper)
 
         # E.g., `db0 -> time`, but `xi NOT-> x`
         intervals = intervals.promote(lambda d: not d.is_Sub)