tests: Add additional test

Author: EdCaunt

tests/test_symbolics.py

@@ -7,7 +7,7 @@
 from sympy import Expr, Symbol
 from devito import (Constant, Dimension, Grid, Function, solve, TimeFunction, Eq,  # noqa
                     Operator, SubDimension, norm, Le, Ge, Gt, Lt, Abs, sin, cos,
-                    Min, Max)
+                    Min, Max, SubDomain)
 from devito.finite_differences.differentiable import SafeInv, Weights
 from devito.ir import Expression, FindNodes, ccode
 from devito.symbolics import (retrieve_functions, retrieve_indexed, evalrel,  # noqa
@@ -868,3 +868,23 @@ def test_issue_2577():
     op = Operator(eq)
 
     assert '--' not in str(op.ccode)
+
+
+def test_issue_2577a():
+    class SD0(SubDomain):
+        name = 'sd0'
+
+        def define(self, dimensions):
+            x, = dimensions
+            return {x: ('middle', 1, 1)}
+
+    grid = Grid(shape=(11,))
+
+    sd0 = SD0(grid=grid)
+
+    u = Function(name='u', grid=grid, space_order=2)
+
+    eq_u = Eq(u, -(u*u).dxc, subdomain=sd0)
+
+    op = Operator(eq_u)
+    assert '--' not in str(op.ccode)