New patch release

Author: YingboMa

Project.toml

@@ -1,7 +1,7 @@
 name = "ModelingToolkit"
 uuid = "961ee093-0014-501f-94e3-6117800e7a78"
 authors = ["Chris Rackauckas <[email protected]>"]
-version = "4.3.0"
+version = "4.3.1"
 
 [deps]
 ArrayInterface = "4fba245c-0d91-5ea0-9b3e-6abc04ee57a9"

src/differentials.jl

@@ -89,8 +89,11 @@ function expand_derivatives(O::Term, simplify=true; occurances=nothing)
             else
                 inner = expand_derivatives(D(o.args[1]), false)
                 # if the inner expression is not expandable either, return
-                operation(inner) isa Differential && return O
-                return expand_derivatives(o.op(inner), simplify)
+                if operation(inner) isa Differential
+                    return O
+                else
+                    return expand_derivatives(o.op(inner), simplify)
+                end
             end
         end