Null parameters of C# decimal? type cause NullReferenceException

[ghost]

In our project, we are using Dapper for SqlServer database and MiniProfiler.
After upgrading to MiniProfiler 4.0.133, following sample code (assuming the stored procedure has all respective parameters that accept NULL values):

decimal? a = null;
int? b = null;
Guid? c = null;

await profiledDbConnection.ExecuteScalarAsync<int>("SomeStoredProcedure",
 new { a, b, c },
 commandType: CommandType.StoredProcedure).ConfigureAwait(false)

throws NullReferenceException:

at StackExchange.Profiling.SqlFormatters.SqlServerFormatter.<>c__DisplayClass3_0.<GetWithDecimalFormatter>b__0(SqlTimingParameter p)
at StackExchange.Profiling.SqlFormatters.SqlServerFormatter.GenerateParamText(StringBuilder buffer, List`1 parameters)
at StackExchange.Profiling.SqlFormatters.SqlServerFormatter.FormatSql(String commandText, List`1 parameters, IDbCommand command)
at StackExchange.Profiling.SqlFormatters.SqlServerFormatter.FormatSql(String commandText, List`1 parameters)
at StackExchange.Profiling.SqlFormatters.SqlFormatterExtensions.GetFormattedSql(ISqlFormatter sqlFormatter, String commandText, List`1 parameters, IDbCommand command)
at StackExchange.Profiling.SqlFormatters.SqlFormatterExtensions.GetFormattedSql(ISqlFormatter sqlFormatter, IDbCommand command)
at StackExchange.Profiling.Internal.IDbCommandExtensions.GetTiming(IDbCommand command, String commandType, MiniProfiler profiler, String customType)
at StackExchange.Profiling.MiniProfiler.StackExchange.Profiling.Data.IDbProfiler.ExecuteStart(IDbCommand profiledDbCommand, SqlExecuteType executeType)
at StackExchange.Profiling.Data.ProfiledDbCommand.<ExecuteDbDataReaderAsync>d__35.MoveNext()

If we remove the decimal? parameter, the query works OK. The MiniProfiler version 4.0.0 has no issues with decimal? parameters.

I believe the issue has been introduced in the dotnet/src/MiniProfiler.Shared/SqlFormatters/SqlServerFormatter.cs commit "SQL formatting for numeric types" on Jun 12, 2018

[NickCraver]

Thanks for the report! Fixed for the next release in fb4b1a9, it'll be up on MyGet shortly.

[robertmiles3]

I just hit this in the latest version on NuGet (4.0.133). Since it's in the latest, is there any chance of getting a new package up with this fix?

[NickCraver]

@robertmiles3 absolutely - have a stack trace by chance?

[NickCraver]

Going to close this out since latest should have all the fixes...if anyone's hitting it in 4.0.138 a repro would be super helpful!