1 files changed, 28 insertions, 0 deletions
diff --git a/gcc/testsuite/gfortran.dg/interface_36.f90 b/gcc/testsuite/gfortran.dg/interface_36.f90
new file mode 100644
index 000000000..503229134
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/interface_36.f90
@@ -0,0 +1,28 @@
+! { dg-do compile }
+!
+! PR fortran/48800
+!
+! Contributed by Daniel Carrera
+!
+     pure function runge_kutta_step(t, r_, dr, h) result(res)
+         real, intent(in) :: t, r_(:), h
+         real, dimension(:), allocatable :: k1, k2, k3, k4, res
+         integer :: N
+
+         interface
+             pure function dr(t, r_)  ! { dg-error "cannot have a deferred shape" }
+                 real, intent(in) :: t, r_(:)
+                 real :: dr(:)
+             end function
+         end interface
+
+         N = size(r_)
+         allocate(k1(N),k2(N),k3(N),k4(N),res(N))
+
+         k1 = dr(t, r_)
+         k2 = dr(t + h/2, r_ + k1*h/2)
+         k3 = dr(t + h/2, r_ + k2*h/2)
+         k4 = dr(t + h  , r_ + k3*h)
+
+         res = r_ + (k1 + 2*k2 + 2*k3 + k4) * h/6
+     end function