Test that similar throws a MethodError for unsupported dims types

test/offsetarray.jl

@@ -166,6 +166,21 @@ B = similar(A, (-3:3,1:4))
 B = similar(parent(A), (-3:3,1:4))
 @test isa(B, OffsetArray{Int,2})
 @test indices(B) === (-3:3, 1:4)
+# Check that similar throws a MethodError rather than a
+# StackOverflowError if no appropriate method has been defined
+# (#18107)
+module SimilarUR
+    immutable MyURange <: AbstractUnitRange{Int}
+        start::Int
+        stop::Int
+    end
+    ur = MyURange(1,3)
+    a = Array{Int}(2)
+    @test_throws MethodError similar(a, ur)
+    @test_throws MethodError similar(a, Float64, ur)
+    @test_throws MethodError similar(a, Float64, (ur,))
+    @test_throws MethodError similar(a, (2.0,3.0))
+end
 
 # Indexing with OffsetArray indices
 i1 = OffsetArray([2,1], (-5,))