fix: propagate and respect use_union for get_u0 and get_u0_p

Author: AayushSabharwal

src/systems/diffeqs/abstractodesystem.jl

@@ -722,7 +722,7 @@ function get_u0_p(sys,
     if symbolic_u0
         u0 = varmap_to_vars(u0map, dvs; defaults = defs, tofloat = false, use_union = false)
     else
-        u0 = varmap_to_vars(u0map, dvs; defaults = defs, tofloat = true)
+        u0 = varmap_to_vars(u0map, dvs; defaults = defs, tofloat = true, use_union)
     end
     p = varmap_to_vars(parammap, ps; defaults = defs, tofloat, use_union)
     p = p === nothing ? SciMLBase.NullParameters() : p
@@ -732,7 +732,7 @@ end
 
 function get_u0(
         sys, u0map, parammap = nothing; symbolic_u0 = false,
-        toterm = default_toterm, t0 = nothing)
+        toterm = default_toterm, t0 = nothing, use_union = true)
     dvs = unknowns(sys)
     ps = parameters(sys)
     defs = defaults(sys)
@@ -757,7 +757,7 @@ function get_u0(
         u0 = varmap_to_vars(
             u0map, dvs; defaults = defs, tofloat = false, use_union = false, toterm)
     else
-        u0 = varmap_to_vars(u0map, dvs; defaults = defs, tofloat = true, toterm)
+        u0 = varmap_to_vars(u0map, dvs; defaults = defs, tofloat = true, use_union, toterm)
     end
     t0 !== nothing && delete!(defs, get_iv(sys))
     return u0, defs
@@ -836,7 +836,7 @@ function process_DEProblem(constructor, sys::AbstractODESystem, u0map, parammap;
 
     if has_index_cache(sys) && get_index_cache(sys) !== nothing
         u0, defs = get_u0(sys, trueinit, parammap; symbolic_u0,
-            t0 = constructor <: Union{DDEFunction, SDDEFunction} ? nothing : t)
+            t0 = constructor <: Union{DDEFunction, SDDEFunction} ? nothing : t, use_union)
         check_eqs_u0(eqs, dvs, u0; kwargs...)
         p = if parammap === nothing ||
                parammap == SciMLBase.NullParameters() && isempty(defs)

src/utils.jl

@@ -689,8 +689,9 @@ function promote_to_concrete(vs; tofloat = true, use_union = true)
         if use_union
             C = Union{C, E}
         else
-            @assert C==E "`promote_to_concrete` can't make type $E uniform with $C"
-            C = E
+            C2 = promote_type(C, E)
+            @assert C2==E || C2==C "`promote_to_concrete` can't make type $E uniform with $C"
+            C = C2
         end
     end
 

test/odesystem.jl

@@ -1177,7 +1177,7 @@ end
     sys = structural_simplify(ODESystem([D(x) ~ P], t, [x], [P]; name = :sys))
 
     function x_at_1(P)
-        prob = ODEProblem(sys, [x => P], (0.0, 1.0), [sys.P => P])
+        prob = ODEProblem(sys, [x => P], (0.0, 1.0), [sys.P => P], use_union = false)
         return solve(prob, Tsit5())(1.0)
     end