From 0bbb7562cdf25405ca160c604222cf6d1ae25842 Mon Sep 17 00:00:00 2001
From: odow <o.dowson@gmail.com>
Date: Tue, 18 Jun 2024 09:27:52 +1200
Subject: [PATCH] Fix methods for calling value on a ::Number

---
 src/variables.jl      |  8 ++++++--
 test/test_variable.jl | 11 +++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/variables.jl b/src/variables.jl
index 89f649580ef..64189327e34 100644
--- a/src/variables.jl
+++ b/src/variables.jl
@@ -2457,8 +2457,12 @@ function value(::AbstractArray{<:AbstractJuMPScalar})
     )
 end
 
-value(::_MA.Zero) = 0.0
-value(x::Number) = x
+# Fallback. See JuMP#3775
+value(::_MA.Zero; result::Int = 1) = 0.0
+
+value(x::Number; result::Int = 1) = x
+
+value(::Function, x::Number) = x
 
 function _info_from_variable(v::GenericVariableRef)
     has_lb = has_lower_bound(v)
diff --git a/test/test_variable.jl b/test/test_variable.jl
index e744ae85723..22b5ff2ba93 100644
--- a/test/test_variable.jl
+++ b/test/test_variable.jl
@@ -1651,4 +1651,15 @@ function test_variable_normalized_coefficient_vector_quadratic()
     return
 end
 
+function test_value_number()
+    model = Model()
+    @variable(model, x, start = 2)
+    @expression(model, expr[i in 0:2], (1 + x)^i)
+    y = Containers.DenseAxisArray([1, 3, 9], 0:2)
+    @test ≈(value.(start_value, expr), y)
+    @test value(expr[0]; result = 1) == 1
+    @test value(expr[0]; result = 2) == 1
+    return
+end
+
 end  # module TestVariable