Fix tests

src/Compilers/VisualBasic/Test/CommandLine/CommandLineTests.vb

@@ -10088,7 +10088,7 @@ dotnet_diagnostic.BC42024.severity = warning;
             VerifyOutput(dir, src, includeCurrentAssemblyAsAnalyzerReference:=False, additionalFlags:={"/nowarn:42024", globalOption})
 
             VerifyOutput(dir, src, includeCurrentAssemblyAsAnalyzerReference:=False, expectedWarningCount:=1, additionalFlags:={globalOption, specificOption})
-            VerifyOutput(dir, src, includeCurrentAssemblyAsAnalyzerReference:=False, expectedWarningCount:=1, additionalFlags:={"/nowarn:BC42024", globalOption, specificOption})
+            VerifyOutput(dir, src, includeCurrentAssemblyAsAnalyzerReference:=False, expectedWarningCount:=0, additionalFlags:={"/nowarn:BC42024", globalOption, specificOption})
         End Sub
 
         <Theory, CombinatorialData>

src/Workspaces/Core/Portable/Shared/Extensions/DiagnosticDescriptorExtensions.cs

@@ -31,8 +31,8 @@ public static ReportDiagnostic GetEffectiveSeverity(this DiagnosticDescriptor de
             // Apply analyzer config options, unless configured with a non-default value in compilation options.
             // Note that compilation options (/nowarn, /warnaserror) override analyzer config options.
             if (analyzerConfigOptions.HasValue &&
-                !compilationOptions.SpecificDiagnosticOptions.TryGetValue(descriptor.Id, out var reportDiagnostic) &&
-                reportDiagnostic != ReportDiagnostic.Default)
+                (!compilationOptions.SpecificDiagnosticOptions.TryGetValue(descriptor.Id, out var reportDiagnostic) ||
+                 reportDiagnostic == ReportDiagnostic.Default))
             {
                 if (analyzerConfigOptions.Value.TreeOptions.TryGetValue(descriptor.Id, out reportDiagnostic) && reportDiagnostic != ReportDiagnostic.Default ||
                     TryGetSeverityFromBulkConfiguration(descriptor, analyzerConfigOptions.Value, out reportDiagnostic))