Fix toplevel-global behaviour in ExprSplitter (#511)

Co-authored-by: Shuhei Kadowaki <40514306+aviatesk@users.noreply.github.com>

src/construct.jl

@@ -435,10 +435,12 @@ function push_modex!(iter::ExprSplitter, mod::Module, ex::Expr)
     if ex.head === :toplevel || ex.head === :block
         # Issue #427
         modifies_scope = false
-        for a in ex.args
-            if isa(a, Expr) && a.head ∈ (:local, :global)
-                modifies_scope = true
-                break
+        if ex.head === :block
+            for a in ex.args
+                if isa(a, Expr) && a.head ∈ (:local, :global)
+                    modifies_scope = true
+                    break
+                end
             end
         end
         push!(iter.index, modifies_scope ? 0 : 1)

test/toplevel.jl

@@ -540,3 +540,25 @@ end
     modexs = collect(ExprSplitter(@__MODULE__, ex))
     @test length(modexs) == 3
 end
+
+@testset "toplevel scope annotation" begin
+    ex = Base.parse_input_line("""
+    global foo_g = 10
+    sin(foo_g)
+    """)
+    modexs = collect(ExprSplitter(@__MODULE__, ex))
+    for (mod, ex) in modexs
+        @test JuliaInterpreter.finish!(Frame(mod, ex), true) === nothing
+    end
+    @test length(modexs) == 2
+
+    ex = Base.parse_input_line("""
+    local foo = 10
+    sin(42)
+    """)
+    modexs = collect(ExprSplitter(@__MODULE__, ex))
+    for (mod, ex) in modexs
+        @test JuliaInterpreter.finish!(Frame(mod, ex), true) === nothing
+    end
+    @test length(modexs) == 2
+end