Always use similar as fallback when resize throws in applying composite maps (#221)

Co-authored-by: Daniel Karrasch <[email protected]>

Author: krcools

Project.toml

@@ -1,6 +1,6 @@
 name = "LinearMaps"
 uuid = "7a12625a-238d-50fd-b39a-03d52299707e"
-version = "3.11.1"
+version = "3.11.2"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

src/composition.jl

@@ -239,11 +239,7 @@ function _resize(dest::AbstractVector, sz::Tuple{<:Integer})
     try
         resize!(dest, sz[1])
     catch err
-        if err == ErrorException("cannot resize array with shared data")
-            dest = similar(dest, sz)
-        else
-            rethrow(err)
-        end
+        dest = similar(dest, sz)
     end
     dest
 end

test/nontradaxes.jl

@@ -70,4 +70,19 @@ using Test, LinearMaps, LinearAlgebra, BlockArrays
     B2u = B2*u; L2u = L2*u
     @test axes(B2u)[1] == axes(L2u)[1] == axes(B2)[1] == axes(L2)[1]
     @test blocklengths(axes(B2u)[1]) == blocklengths(axes(L2u)[1]) == [2,2]
+
+    D1 = rand(4,5)
+    D2 = rand(5,3)
+    D3 = rand(3,6)
+    D4 = rand(6,6)
+    A1 = PseudoBlockMatrix(D1, [1,3], [2,3])
+    A2 = PseudoBlockMatrix(D2, [2,3], [2,1])
+    A3 = PseudoBlockMatrix(D3, [2,1], [3,2,1])
+    A4 = PseudoBlockMatrix(D4, [3,2,1], [3,2,1])
+    u = rand(6)
+    x = PseudoBlockVector(u, [3,2,1])
+    L = LinearMap(A1) * LinearMap(A2) * LinearMap(A3) * LinearMap(A4)
+    y = L * x
+    v = Vector(y)
+    @test v ≈ D1*(D2*(D3*(D4*u)))
 end