From cd4384bc3eaafd018ec067faa7b0247ba79d353d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Jakes=CC=8C?= <jan@jakes.pro>
Date: Tue, 27 Oct 2026 13:47:32 +0100
Subject: [PATCH] Pad odd-length hexadecimal literals

Add a leading zero to odd-length 0x literals before translating them to SQLite blob literals. Preserve leading zeros and keep rejecting odd-length quoted hexadecimal literals.

Cover SELECT, HEX(), INSERT, UPDATE, and literal edge cases.

Fixes https://github.com/WordPress/sqlite-database-integration/issues/543
---
 .../src/sqlite/class-wp-mysql-on-sqlite.php   |  8 +-
 .../tests/WP_MySQL_On_SQLite_Tests.php        | 80 +++++++++++++++++--
 .../WP_MySQL_On_SQLite_Translation_Tests.php  | 10 +++
 3 files changed, 90 insertions(+), 8 deletions(-)

diff --git a/packages/mysql-on-sqlite/src/sqlite/class-wp-mysql-on-sqlite.php b/packages/mysql-on-sqlite/src/sqlite/class-wp-mysql-on-sqlite.php
index ff92b9480..522b66b52 100644
--- a/packages/mysql-on-sqlite/src/sqlite/class-wp-mysql-on-sqlite.php
+++ b/packages/mysql-on-sqlite/src/sqlite/class-wp-mysql-on-sqlite.php
@@ -4541,7 +4541,13 @@ private function translate_token( WP_MySQL_Token $token ): ?string {
 				 */
 				$value = $token->get_value();
 				if ( '0' === $value[0] && 'x' === $value[1] ) {
-					return sprintf( "x'%s'", substr( $value, 2 ) );
+					$hex = substr( $value, 2 );
+
+					// MySQL pads odd-length 0x literals with a leading zero.
+					if ( 1 === strlen( $hex ) % 2 ) {
+						$hex = '0' . $hex;
+					}
+					return sprintf( "x'%s'", $hex );
 				}
 				return $value;
 			case WP_MySQL_Lexer::AUTO_INCREMENT_SYMBOL:
diff --git a/packages/mysql-on-sqlite/tests/WP_MySQL_On_SQLite_Tests.php b/packages/mysql-on-sqlite/tests/WP_MySQL_On_SQLite_Tests.php
index 63fdb9ea5..aac2728a4 100644
--- a/packages/mysql-on-sqlite/tests/WP_MySQL_On_SQLite_Tests.php
+++ b/packages/mysql-on-sqlite/tests/WP_MySQL_On_SQLite_Tests.php
@@ -11153,15 +11153,81 @@ public function testBinaryLiterals(): void {
 		$this->assertEquals( array( (object) array( '0b000000001' => pack( 'H*', '0001' ) ) ), $result );
 	}
 
-	public function testHexadecimalLiterals(): void {
-		$result = $this->assertQuery( 'SELECT 0x417a' );
-		$this->assertEquals( array( (object) array( '0x417a' => 'Az' ) ), $result );
+	/**
+	 * @dataProvider hexadecimalLiterals
+	 */
+	public function testHexadecimalLiterals( string $literal, string $hex ): void {
+		$result = $this->assertQuery( "SELECT $literal" );
+		$this->assertEquals( array( (object) array( $literal => hex2bin( $hex ) ) ), $result );
+
+		$result = $this->assertQuery( "SELECT HEX($literal) AS value" );
+		$this->assertSame( $hex, $result[0]->value );
+	}
 
-		$result = $this->assertQuery( "SELECT x'417a'" );
-		$this->assertEquals( array( (object) array( "x'417a'" => 'Az' ) ), $result );
+	public static function hexadecimalLiterals(): array {
+		return array(
+			array( '0x0', '00' ),
+			array( '0x1', '01' ),
+			array( '0xF', '0F' ),
+			array( '0x711', '0711' ),
+			array( '0xaBc', '0ABC' ),
+			array( '0x0711', '0711' ),
+			array( '0x00711', '000711' ),
+			array( '0x000711', '000711' ),
+			array( '0x000', '0000' ),
+			array( '0x123456789abcdef01', '0123456789ABCDEF01' ),
+			array( '0x417a', '417A' ),
+			array( "x'417a'", '417A' ),
+			array( "X'417a'", '417A' ),
+			array( "x''", '' ),
+			array( "X''", '' ),
+		);
+	}
 
-		$result = $this->assertQuery( "SELECT X'417a'" );
-		$this->assertEquals( array( (object) array( "X'417a'" => 'Az' ) ), $result );
+	public function testOddLengthHexadecimalLiteralsInWrites(): void {
+		$this->assertQuery( 'CREATE TABLE t (id INT PRIMARY KEY, title TEXT, name VARCHAR(200), data BLOB)' );
+		$this->assertQuery( 'INSERT INTO t (id, title, name, data) VALUES (51701, 0x711, 0x711, 0x711)' );
+		$this->assertEquals(
+			array(
+				(object) array(
+					'id'    => '51701',
+					'title' => '0711',
+					'name'  => '0711',
+					'data'  => '0711',
+				),
+			),
+			$this->assertQuery( 'SELECT id, HEX(title) AS title, HEX(name) AS name, HEX(data) AS data FROM t' )
+		);
+
+		$this->assertQuery( 'UPDATE t SET title = 0x00711, name = 0x00711, data = 0x00711 WHERE id = 51701' );
+		$this->assertEquals(
+			array(
+				(object) array(
+					'id'    => '51701',
+					'title' => '000711',
+					'name'  => '000711',
+					'data'  => '000711',
+				),
+			),
+			$this->assertQuery( 'SELECT id, HEX(title) AS title, HEX(name) AS name, HEX(data) AS data FROM t' )
+		);
+	}
+
+	/**
+	 * @dataProvider oddLengthQuotedHexadecimalLiterals
+	 */
+	public function testOddLengthQuotedHexadecimalLiteralsAreRejected( string $literal ): void {
+		$this->expectException( WP_MySQL_On_SQLite_Exception::class );
+		$this->assertQuery( "SELECT $literal" );
+	}
+
+	public static function oddLengthQuotedHexadecimalLiterals(): array {
+		return array(
+			array( "x'1'" ),
+			array( "X'1'" ),
+			array( "x'711'" ),
+			array( "X'711'" ),
+		);
 	}
 
 	public function testColumnInfo(): void {
diff --git a/packages/mysql-on-sqlite/tests/WP_MySQL_On_SQLite_Translation_Tests.php b/packages/mysql-on-sqlite/tests/WP_MySQL_On_SQLite_Translation_Tests.php
index e170f3395..d0d522db4 100644
--- a/packages/mysql-on-sqlite/tests/WP_MySQL_On_SQLite_Translation_Tests.php
+++ b/packages/mysql-on-sqlite/tests/WP_MySQL_On_SQLite_Translation_Tests.php
@@ -1742,6 +1742,16 @@ public function testHexadecimalLiterals(): void {
 			"SELECT x'417a' AS `0x417a`",
 			'SELECT 0x417a'
 		);
+
+		// Odd-length 0x... values need a leading zero to form full bytes.
+		$this->assertQuery(
+			"SELECT x'0711' AS `0x711`",
+			'SELECT 0x711'
+		);
+		$this->assertQuery(
+			"SELECT x'000711' AS `0x00711`",
+			'SELECT 0x00711'
+		);
 	}
 
 	public function testSystemVariables(): void {