From 65b16fbfe557ec744909a54662cd3c802520672a Mon Sep 17 00:00:00 2001
From: Stephan <stephane@umbraco.dk>
Date: Fri, 11 Mar 2016 14:18:08 +0100
Subject: [PATCH] U4-8154 - bugfix Sql query expressions parsing

---
 .../Querying/BaseExpressionHelper.cs          | 78 +++++++++++++++----
 .../Persistence/Querying/PetaPocoSqlTests.cs  | 22 ++++++
 2 files changed, 86 insertions(+), 14 deletions(-)

diff --git a/src/Umbraco.Core/Persistence/Querying/BaseExpressionHelper.cs b/src/Umbraco.Core/Persistence/Querying/BaseExpressionHelper.cs
index f3cbe5a583..ab6cdb341c 100644
--- a/src/Umbraco.Core/Persistence/Querying/BaseExpressionHelper.cs
+++ b/src/Umbraco.Core/Persistence/Querying/BaseExpressionHelper.cs
@@ -128,6 +128,34 @@ namespace Umbraco.Core.Persistence.Querying
                     right = Visit(b.Right);
                 }
             }
+            else if (operand == "=")
+            {
+                // deal with (x == true|false) - most common
+                var constRight = b.Right as ConstantExpression;
+                if (constRight != null && constRight.Type == typeof (bool))
+                    return ((bool) constRight.Value) ? VisitNotNot(b.Left) : VisitNot(b.Left);
+                right = Visit(b.Right);
+
+                // deal with (true|false == x) - why not
+                var constLeft = b.Left as ConstantExpression;
+                if (constLeft != null && constLeft.Type == typeof (bool))
+                    return ((bool) constLeft.Value) ? VisitNotNot(b.Right) : VisitNot(b.Right);
+                left = Visit(b.Left);
+            }
+            else if (operand == "<>")
+            {
+                // deal with (x != true|false) - most common
+                var constRight = b.Right as ConstantExpression;
+                if (constRight != null && constRight.Type == typeof(bool))
+                    return ((bool) constRight.Value) ? VisitNot(b.Left) : VisitNotNot(b.Left);
+                right = Visit(b.Right);
+
+                // deal with (true|false != x) - why not
+                var constLeft = b.Left as ConstantExpression;
+                if (constLeft != null && constLeft.Type == typeof(bool))
+                    return ((bool) constLeft.Value) ? VisitNot(b.Right) : VisitNotNot(b.Right);
+                left = Visit(b.Left);
+            }
             else
             {
                 left = Visit(b.Left);
@@ -231,25 +259,47 @@ namespace Umbraco.Core.Persistence.Querying
             switch (u.NodeType)
             {
                 case ExpressionType.Not:
-                    var o = Visit(u.Operand);
-
-                    //use a Not equal operator instead of <> since we don't know that <> works in all sql servers
-
-                    switch (u.Operand.NodeType)
-                    {
-                        case ExpressionType.MemberAccess:
-                            //In this case it wil be a false property , i.e. x => !Trashed
-                            SqlParameters.Add(true);
-                            return string.Format("NOT ({0} = @0)", o);                            
-                        default:
-                            //In this case it could be anything else, such as: x => !x.Path.StartsWith("-20")
-                            return string.Format("NOT ({0})", o);                            
-                    }
+                    return VisitNot(u.Operand);
                 default:
                     return Visit(u.Operand);
             }
         }
 
+        private string VisitNot(Expression exp)
+        {
+            var o = Visit(exp);
+
+            // use a "NOT (...)" syntax instead of "<>" since we don't know whether "<>" works in all sql servers
+            // also, x.StartsWith(...) translates to "x LIKE '...%'" which we cannot "<>" and have to "NOT (...")
+
+            switch (exp.NodeType)
+            {
+                case ExpressionType.MemberAccess:
+                    // false property , i.e. x => !Trashed
+                    SqlParameters.Add(true);
+                    return "NOT (" + o + " = @0)";
+                default:
+                    // could be anything else, such as: x => !x.Path.StartsWith("-20")
+                    return "NOT (" + o + ")";
+            }
+        }
+
+        private string VisitNotNot(Expression exp)
+        {
+            var o = Visit(exp);
+
+            switch (exp.NodeType)
+            {
+                case ExpressionType.MemberAccess:
+                    // true property, i.e. x => Trashed
+                    SqlParameters.Add(true);
+                    return o + " = @0";
+                default:
+                    // could be anything else, such as: x => x.Path.StartsWith("-20")
+                    return o;
+            }
+        }
+
         protected virtual string VisitNewArray(NewArrayExpression na)
         {
 
diff --git a/src/Umbraco.Tests/Persistence/Querying/PetaPocoSqlTests.cs b/src/Umbraco.Tests/Persistence/Querying/PetaPocoSqlTests.cs
index f934b0c536..98d9d9551c 100644
--- a/src/Umbraco.Tests/Persistence/Querying/PetaPocoSqlTests.cs
+++ b/src/Umbraco.Tests/Persistence/Querying/PetaPocoSqlTests.cs
@@ -51,6 +51,18 @@ namespace Umbraco.Tests.Persistence.Querying
             Assert.AreEqual("-20%", sql.Arguments[1]);
         }
 
+        [Test]
+        public void Where_Clause_With_EqualsFalse_Starts_With()
+        {
+            var level = 1;
+            var sql = new Sql("SELECT *").From<NodeDto>().Where<NodeDto>(x => x.Level == level && x.Path.StartsWith("-20") == false);
+
+            Assert.AreEqual("SELECT * FROM [umbracoNode] WHERE ([umbracoNode].[level] = @0 AND NOT (upper([umbracoNode].[path]) LIKE upper(@1)))", sql.SQL.Replace("\n", " "));
+            Assert.AreEqual(2, sql.Arguments.Length);
+            Assert.AreEqual(level, sql.Arguments[0]);
+            Assert.AreEqual("-20%", sql.Arguments[1]);
+        }
+
         [Test]
         public void Where_Clause_With_Equals_Clause()
         {
@@ -71,6 +83,16 @@ namespace Umbraco.Tests.Persistence.Querying
             Assert.AreEqual(true, sql.Arguments[0]);
         }
 
+        [Test]
+        public void Where_Clause_With_EqualsFalse_Boolean()
+        {
+            var sql = new Sql("SELECT *").From<NodeDto>().Where<NodeDto>(x => x.Trashed == false);
+
+            Assert.AreEqual("SELECT * FROM [umbracoNode] WHERE (NOT ([umbracoNode].[trashed] = @0))", sql.SQL.Replace("\n", " "));
+            Assert.AreEqual(1, sql.Arguments.Length);
+            Assert.AreEqual(true, sql.Arguments[0]);
+        }
+
         [Test]
         public void Where_Clause_With_Boolean()
         {