Fix error parsing -- comments in SQL. Fixes #429

Author: bgrainger

src/MySqlConnector/Core/SqlParser.cs

@@ -75,7 +75,6 @@ public int Parse(string sql)
 				{
 					if (ch == ' ')
 					{
-						beforeCommentState = state;
 						state = State.EndOfLineComment;
 					}
 					else
@@ -121,7 +120,10 @@ public int Parse(string sql)
 						throw new InvalidOperationException("Unexpected state: {0}".FormatInvariant(state));
 
 					if (ch == '-')
+					{
+						beforeCommentState = state;
 						state = State.Hyphen;
+					}
 					else if (ch == '/')
 						state = State.ForwardSlash;
 					else if (ch == '\'')

tests/MySqlConnector.Tests/MySqlConnector.Tests.csproj

@@ -34,7 +34,7 @@
 
   <ItemGroup Condition=" '$(Configuration)' == 'Baseline' ">
     <PackageReference Include="MySql.Data" Version="6.9.9" />
-    <Compile Remove="ConnectionTests.cs;FakeMySqlServer.cs;FakeMySqlServerConnection.cs;LoadBalancerTests.cs;NormalizeTests.cs;TypeMapperTests.cs;Utf8Tests.cs" />
+    <Compile Remove="ConnectionTests.cs;FakeMySqlServer.cs;FakeMySqlServerConnection.cs;LoadBalancerTests.cs;NormalizeTests.cs;StatementPreparerTests.cs;TypeMapperTests.cs;Utf8Tests.cs" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net462' ">

tests/MySqlConnector.Tests/StatementPreparerTests.cs

@@ -0,0 +1,46 @@
+using System.Text;
+using MySql.Data.MySqlClient;
+using MySqlConnector.Core;
+using MySqlConnector.Utilities;
+using Xunit;
+
+namespace MySqlConnector.Tests
+{
+	public class StatementPreparerTests
+	{
+		[Theory]
+		[InlineData(GoodSqlText)]
+		[InlineData(AnotherGoodSqlText)]
+		[InlineData(AnotherGoodSqlText2)]
+		[InlineData(BadSqlText)]
+		public void PrepareQuery(string sql)
+		{
+			var parameters = new MySqlParameterCollection();
+			parameters.AddWithValue("c2", 3);
+
+			var parsedRequest1 = Encoding.UTF8.GetString(new StatementPreparer(sql, parameters, StatementPreparerOptions.None).ParseAndBindParameters().Slice(1));
+
+			Assert.Matches("column2 = 3", parsedRequest1);
+		}
+
+		private const string BadSqlText = @"SELECT Id
+FROM mytable
+WHERE column1 = 2 -- mycomment
+  AND column2 = @c2";
+
+		private const string GoodSqlText = @"SELECT Id
+FROM mytable
+WHERE column1 = 2
+AND column2 = @c2";
+
+		private const string AnotherGoodSqlText = @"SELECT Id
+FROM mytable
+WHERE column1 = 2  -- mycomment
+AND column2 = @c2";
+
+		private const string AnotherGoodSqlText2 = @"SELECT Id
+FROM mytable
+WHERE column1 = 2 -- mycomment
+AND column2 = @c2";
+	}
+}