From fff327e69c313dc5b1cbae63e912c95b45ca94a8 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Mon, 31 Mar 2025 13:00:07 -0700
Subject: [PATCH 1/3] fix double negatives

---
 enginetest/queries/script_queries.go | 34 ++++++++++++++++++++++++++++
 sql/analyzer/optimization_rules.go   |  4 +++-
 sql/types/typecheck.go               |  5 ++++
 3 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/enginetest/queries/script_queries.go b/enginetest/queries/script_queries.go
index afabb2c3d8..1d1df0b5a6 100644
--- a/enginetest/queries/script_queries.go
+++ b/enginetest/queries/script_queries.go
@@ -7799,6 +7799,40 @@ where
 			},
 		},
 	},
+	{
+		Name:    "not expression optimization",
+		Dialect: "mysql",
+		SetUpScript: []string{
+			"create table t (i int);",
+			"insert into t values (123);",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query:    "select * from t where 1 = (not(not(i)))",
+				Expected: []sql.Row{
+					{123},
+				},
+			},
+			{
+				Query:    "select * from t where true = (not(not(i)))",
+				Expected: []sql.Row{
+					{123},
+				},
+			},
+			{
+				Query:    "select * from t where true = (not(not(i = 123)))",
+				Expected: []sql.Row{
+					{123},
+				},
+			},
+			{
+				Query:    "select * from t where false = (not(not(i != 123)))",
+				Expected: []sql.Row{
+					{123},
+				},
+			},
+		},
+	},
 }
 
 var SpatialScriptTests = []ScriptTest{
diff --git a/sql/analyzer/optimization_rules.go b/sql/analyzer/optimization_rules.go
index 71c4c5e520..329b83af1a 100644
--- a/sql/analyzer/optimization_rules.go
+++ b/sql/analyzer/optimization_rules.go
@@ -431,7 +431,9 @@ func pushNotFiltersHelper(e sql.Expression) (sql.Expression, error) {
 	// NOT(NOT(c))=>c
 	if not, _ := e.(*expression.Not); not != nil {
 		if f, _ := not.Child.(*expression.Not); f != nil {
-			return pushNotFiltersHelper(f.Child)
+			if types.IsBoolean(f.Child.Type()) {
+				return pushNotFiltersHelper(f.Child)
+			}
 		}
 	}
 
diff --git a/sql/types/typecheck.go b/sql/types/typecheck.go
index b2cb7f818d..5c090d72af 100644
--- a/sql/types/typecheck.go
+++ b/sql/types/typecheck.go
@@ -20,6 +20,11 @@ import (
 	"github.com/dolthub/go-mysql-server/sql"
 )
 
+// IsBoolean checks if t is a boolean type.
+func IsBoolean(t sql.Type) bool {
+	return t == Boolean
+}
+
 // IsBlobType checks if t is BLOB
 func IsBlobType(t sql.Type) bool {
 	if t == nil {

From 9bfbcaf4712018877ce34587a67954c29ce333e5 Mon Sep 17 00:00:00 2001
From: jycor <jycor@users.noreply.github.com>
Date: Mon, 31 Mar 2025 20:03:56 +0000
Subject: [PATCH 2/3] [ga-format-pr] Run ./format_repo.sh to fix formatting

---
 enginetest/queries/script_queries.go | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/enginetest/queries/script_queries.go b/enginetest/queries/script_queries.go
index 1d1df0b5a6..122a7f75a2 100644
--- a/enginetest/queries/script_queries.go
+++ b/enginetest/queries/script_queries.go
@@ -7808,25 +7808,25 @@ where
 		},
 		Assertions: []ScriptTestAssertion{
 			{
-				Query:    "select * from t where 1 = (not(not(i)))",
+				Query: "select * from t where 1 = (not(not(i)))",
 				Expected: []sql.Row{
 					{123},
 				},
 			},
 			{
-				Query:    "select * from t where true = (not(not(i)))",
+				Query: "select * from t where true = (not(not(i)))",
 				Expected: []sql.Row{
 					{123},
 				},
 			},
 			{
-				Query:    "select * from t where true = (not(not(i = 123)))",
+				Query: "select * from t where true = (not(not(i = 123)))",
 				Expected: []sql.Row{
 					{123},
 				},
 			},
 			{
-				Query:    "select * from t where false = (not(not(i != 123)))",
+				Query: "select * from t where false = (not(not(i != 123)))",
 				Expected: []sql.Row{
 					{123},
 				},

From 9fdd50dca1d971b8f6ce39ca6a2f2ed3d71aaf00 Mon Sep 17 00:00:00 2001
From: James Cor <james@dolthub.com>
Date: Mon, 31 Mar 2025 13:39:15 -0700
Subject: [PATCH 3/3] fix test

---
 enginetest/queries/script_queries.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/enginetest/queries/script_queries.go b/enginetest/queries/script_queries.go
index 122a7f75a2..2237701910 100644
--- a/enginetest/queries/script_queries.go
+++ b/enginetest/queries/script_queries.go
@@ -5165,9 +5165,9 @@ CREATE TABLE tab3 (
 				},
 			},
 			{
-				Query: "select unix_timestamp(d), unix_timestamp(tt) from t;",
+				Query: "select unix_timestamp(d), substring(cast(unix_timestamp(tt) as char(128)), -6) from t;",
 				Expected: []sql.Row{
-					{"1577898000", "1743140096.123456"},
+					{"1577898000", "123456"},
 				},
 			},
 		},