Fix and test InexactError

Author: odow

src/functions.jl

@@ -1213,8 +1213,8 @@ function Base.convert(
     ::Type{VectorAffineFunction{T}},
     f::VectorQuadraticFunction{T},
 ) where {T}
-    if any(!iszero(t.coef) for t in f.quadratic_terms)
-        throw(InexactError, :convert, VectorAffineFunction{T}, f)
+    if any(!iszero(t.scalar_term.coefficient) for t in f.quadratic_terms)
+        throw(InexactError(:convert, VectorAffineFunction{T}, f))
     end
     return VectorAffineFunction{T}(f.affine_terms, f.constants)
 end