VB

src/Compilers/VisualBasic/Portable/Compilation/VisualBasicCompilation.vb

@@ -661,7 +661,13 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                 Return Me
             End If
 
-            ' Reference binding doesn't depend on previous submission so we can reuse it.
+            ' Metadata references are inherited from the previous submission,
+            ' so we can only reuse the manager if we can guarantee that these references are the same.
+            ' Check if the previous script compilation doesn't change. 
+
+            ' TODO Consider comparing the metadata references if they have been bound already.
+            ' https://github.com/dotnet/roslyn/issues/43397
+            Dim reuseReferenceManager = ReferenceEquals(ScriptCompilationInfo?.PreviousScriptCompilation, info?.PreviousScriptCompilation)
 
             Return New VisualBasicCompilation(
                 Me.AssemblyName,
@@ -677,7 +683,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                 info?.GlobalsType,
                 info IsNot Nothing,
                 _referenceManager,
-                reuseReferenceManager:=True)
+                reuseReferenceManager)
         End Function
 
         ''' <summary>

src/Compilers/VisualBasic/Test/Semantic/Compilation/CompilationAPITests.vb

@@ -2176,6 +2176,43 @@ End Class
             Assert.False(arc.ReferenceManagerEquals(ars))
         End Sub
 
+        <Fact>
+        Public Sub ReferenceManagerReuse_WithScriptCompilationInfo()
+            ' Note The following results would change if we optimized sharing more: https://github.com/dotnet/roslyn/issues/43397
+
+            Dim c1 = VisualBasicCompilation.CreateScriptCompilation("c1")
+            Assert.NotNull(c1.ScriptCompilationInfo)
+            Assert.Null(c1.ScriptCompilationInfo.PreviousScriptCompilation)
+
+            Dim c2 = c1.WithScriptCompilationInfo(Nothing)
+            Assert.Null(c2.ScriptCompilationInfo)
+            Assert.True(c2.ReferenceManagerEquals(c1))
+
+            Dim c3 = c2.WithScriptCompilationInfo(New VisualBasicScriptCompilationInfo(previousCompilationOpt:=Nothing, returnType:=GetType(Integer), globalsType:=Nothing))
+            Assert.NotNull(c3.ScriptCompilationInfo)
+            Assert.Null(c3.ScriptCompilationInfo.PreviousScriptCompilation)
+            Assert.True(c3.ReferenceManagerEquals(c2))
+
+            Dim c4 = c3.WithScriptCompilationInfo(Nothing)
+            Assert.Null(c4.ScriptCompilationInfo)
+            Assert.True(c4.ReferenceManagerEquals(c3))
+
+            Dim c5 = c4.WithScriptCompilationInfo(New VisualBasicScriptCompilationInfo(previousCompilationOpt:=c1, returnType:=GetType(Integer), globalsType:=Nothing))
+            Assert.False(c5.ReferenceManagerEquals(c4))
+
+            Dim c6 = c5.WithScriptCompilationInfo(New VisualBasicScriptCompilationInfo(previousCompilationOpt:=c1, returnType:=GetType(Boolean), globalsType:=Nothing))
+            Assert.True(c6.ReferenceManagerEquals(c5))
+
+            Dim c7 = c6.WithScriptCompilationInfo(New VisualBasicScriptCompilationInfo(previousCompilationOpt:=c2, returnType:=GetType(Boolean), globalsType:=Nothing))
+            Assert.False(c7.ReferenceManagerEquals(c6))
+
+            Dim c8 = c7.WithScriptCompilationInfo(New VisualBasicScriptCompilationInfo(previousCompilationOpt:=Nothing, returnType:=GetType(Boolean), globalsType:=Nothing))
+            Assert.False(c8.ReferenceManagerEquals(c7))
+
+            Dim c9 = c8.WithScriptCompilationInfo(Nothing)
+            Assert.True(c9.ReferenceManagerEquals(c8))
+        End Sub
+
         Private Class EvolvingTestReference
             Inherits PortableExecutableReference