Simple quick fix for refactor issue

Author: rayegun

src/factorization.jl

@@ -267,6 +267,7 @@ end
 
 Base.@kwdef struct UMFPACKFactorization <: AbstractFactorization
     reuse_symbolic::Bool = true
+    check::Bool = true # Check factorization re-use
 end
 
 function init_cacheval(alg::UMFPACKFactorization, A, b, u, Pl, Pr, maxiters::Int, abstol,
@@ -290,7 +291,13 @@ function SciMLBase.solve(cache::LinearCache, alg::UMFPACKFactorization; kwargs..
     if cache.isfresh
         if cache.cacheval !== nothing && alg.reuse_symbolic
             # Caches the symbolic factorization: https://github.com/JuliaLang/julia/pull/33738
-            fact = lu!(cache.cacheval, A)
+            if alg.check && !(SuiteSparse.decrement(SparseArrays.getcolptr(A)) ==
+                 cache.cacheval.colptr &&
+                 SuiteSparse.decrement(SparseArrays.getrowval(A)) == cache.cacheval.rowval)
+                fact = lu(A)
+            else
+                fact = lu!(cache.cacheval, A)
+            end
         else
             fact = lu(A)
         end
@@ -303,6 +310,7 @@ end
 
 Base.@kwdef struct KLUFactorization <: AbstractFactorization
     reuse_symbolic::Bool = true
+    check::Bool = true
 end
 
 function init_cacheval(alg::KLUFactorization, A, b, u, Pl, Pr, maxiters::Int, abstol,
@@ -316,14 +324,20 @@ function SciMLBase.solve(cache::LinearCache, alg::KLUFactorization; kwargs...)
     A = convert(AbstractMatrix, A)
     if cache.isfresh
         if cache.cacheval !== nothing && alg.reuse_symbolic
-            # If we have a cacheval already, run umfpack_symbolic to ensure the symbolic factorization exists
-            # This won't recompute if it does.
-            KLU.klu_analyze!(cache.cacheval)
-            copyto!(cache.cacheval.nzval, A.nzval)
-            if cache.cacheval._numeric === C_NULL # We MUST have a numeric factorization for reuse, unlike UMFPACK.
-                KLU.klu_factor!(cache.cacheval)
+            if alg.check && !(SuiteSparse.decrement(SparseArrays.getcolptr(A)) ==
+                 cache.cacheval.colptr &&
+                 SuiteSparse.decrement(SparseArrays.getrowval(A)) == cache.cacheval.rowval)
+                fact = KLU.klu(A)
+            else
+                # If we have a cacheval already, run umfpack_symbolic to ensure the symbolic factorization exists
+                # This won't recompute if it does.
+                KLU.klu_analyze!(cache.cacheval)
+                copyto!(cache.cacheval.nzval, A.nzval)
+                if cache.cacheval._numeric === C_NULL # We MUST have a numeric factorization for reuse, unlike UMFPACK.
+                    KLU.klu_factor!(cache.cacheval)
+                end
+                fact = KLU.klu!(cache.cacheval, A)
             end
-            fact = KLU.klu!(cache.cacheval, A)
         else
             # New fact each time since the sparsity pattern can change
             # and thus it needs to reallocate

test/basictests.jl

@@ -91,11 +91,11 @@ end
         test_interface(UMFPACKFactorization(), prob1, prob2)
         test_interface(UMFPACKFactorization(reuse_symbolic = false), prob1, prob2)
 
-        # Test that refactoring wrong throws.
+        # Test that refactoring is checked and handled.
         cache = SciMLBase.init(prob1, UMFPACKFactorization(); cache_kwargs...) # initialize cache
         y = solve(cache)
         cache = LinearSolve.set_A(cache, sprand(n, n, 0.8))
-        @test_throws ArgumentError solve(cache)
+        y2 = solve(cache) # we just need to know this doesn't fail.
     end
 
     @testset "KLU Factorization" begin
@@ -111,14 +111,11 @@ end
         test_interface(KLUFactorization(), prob1, prob2)
         test_interface(KLUFactorization(reuse_symbolic = false), prob1, prob2)
 
-        # Test that refactoring wrong throws.
+        # Test that refactoring wrong is checked and handled.
         cache = SciMLBase.init(prob1, KLUFactorization(); cache_kwargs...) # initialize cache
         y = solve(cache)
-        X = copy(A1)
-        X[8, 8] = 0.0
-        X[7, 8] = 1.0
-        cache = LinearSolve.set_A(cache, sparse(X))
-        @test_throws ArgumentError solve(cache)
+        cache = LinearSolve.set_A(cache, sprand(n, n, 0.8))
+        y2 = solve(cache)
     end
 
     @testset "FastLAPACK Factorizations" begin

test/zeroinittests.jl

@@ -4,6 +4,8 @@ A = Diagonal(ones(4))
 b = rand(4)
 A = sparse(A)
 Anz = deepcopy(A)
+C = copy(A)
+C[begin, end] = 1e-8
 A.nzval .= 0
 cache_kwargs = (; verbose = true, abstol = 1e-8, reltol = 1e-8, maxiter = 30)
 
@@ -14,6 +16,9 @@ function test_nonzero_init(alg = nothing)
     cache = LinearSolve.set_A(cache, Anz)
     sol = solve(cache; cache_kwargs...)
     @test sol.u == b
+    cache = LinearSolve.set_A(cache, C)
+    sol = solve(cache; cache_kwargs...)
+    @test sol.u ≈ b
 end
 
 test_nonzero_init()