Make broadcast!(f, A) populate A via independent f() calls rather tha…

…n fill!(A, f()). (#19722) (cherry picked from commit 50a8b96)
JuliaLang · Mar 1, 2017 · 4efacb6 · 4efacb6
1 parent cea0818
commit 4efacb6
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diff --git a/base/broadcast.jl b/base/broadcast.jl
@@ -17,7 +17,7 @@ broadcast(f, x::Number...) = f(x...)
 
 # special cases for "X .= ..." (broadcast!) assignments
 broadcast!(::typeof(identity), X::AbstractArray, x::Number) = fill!(X, x)
-broadcast!(f, X::AbstractArray) = fill!(X, f())
+broadcast!(f, X::AbstractArray) = (@inbounds for I in eachindex(X); X[I] = f(); end; X)
 broadcast!(f, X::AbstractArray, x::Number...) = fill!(X, f(x...))
 function broadcast!{T,S,N}(::typeof(identity), x::AbstractArray{T,N}, y::AbstractArray{S,N})
     check_broadcast_shape(size(x), size(y))

diff --git a/test/broadcast.jl b/test/broadcast.jl
@@ -320,3 +320,6 @@ end
 let A17984 = []
     @test isa(abs.(A17984), Array{Any,1})
 end
+
+# Check that broadcast!(f, A) populates A via independent calls to f (#12277, #19722).
+@test let z = 1; A = broadcast!(() -> z += 1, zeros(2)); A[1] != A[2]; end