Fix for negative number handling (DECIMAL -51.1234 could not read). (#80)

* Fix for negative number handling (DECIMAL -51.1234 could not read). This seems to fix it.
Inspired by fengxiangyun/mysql-replication@a9da836

Author: dominiquegerber

src/MySQLReplication/BinaryDataReader/BinaryDataReader.php

@@ -229,28 +229,27 @@ public function readIntBeBySize(int $size): int
 
     public function readInt8(): int
     {
-        return unpack('c', $this->read(self::UNSIGNED_CHAR_LENGTH))[1];
+        $re = unpack('c', $this->read(self::UNSIGNED_CHAR_LENGTH))[1];
+        return $re >= 0x80 ? $re - 0x100 : $re;
     }
 
     public function readInt16Be(): int
     {
-        return unpack('n', $this->read(self::UNSIGNED_SHORT_LENGTH))[1];
+        $re = unpack('n', $this->read(self::UNSIGNED_SHORT_LENGTH))[1];
+        return $re >= 0x8000 ? $re - 0x10000 : $re;
     }
 
     public function readInt24Be(): int
     {
         $data = unpack('C3', $this->read(self::UNSIGNED_INT24_LENGTH));
-        $res = ($data[1] << 16) | ($data[2] << 8) | $data[3];
-        if ($res >= 0x800000) {
-            $res -= 0x1000000;
-        }
-
-        return $res;
+        $re = ($data[1] << 16) | ($data[2] << 8) | $data[3];
+        return $re >= 0x800000 ? $re - 0x1000000 : $re;
     }
 
     public function readInt32Be(): int
     {
-        return unpack('i', strrev($this->read(self::UNSIGNED_INT32_LENGTH)))[1];
+        $re = unpack('N', $this->read(self::UNSIGNED_INT32_LENGTH))[1];
+        return $re >= 0x80000000 ? $re - 0x100000000 : $re;
     }
 
     public function readInt40Be(): int

tests/Integration/TypesTest.php

@@ -56,12 +56,14 @@ public function shouldBeDecimalLongValues2(): void
      */
     public function shouldBeDecimalNegativeValues(): void
     {
-        $create_query = 'CREATE TABLE test (test DECIMAL(20,10))';
-        $insert_query = 'INSERT INTO test VALUES(-42000.123456)';
+        $create_query = 'CREATE TABLE test (test DECIMAL(20,10), test2 DECIMAL(11,4), test3 DECIMAL(40,30))';
+        $insert_query = 'INSERT INTO test VALUES(-42000.123456, -51.1234, -51.123456789098765432123456789)';
 
         $event = $this->createAndInsertValue($create_query, $insert_query);
 
         self::assertEquals('-42000.1234560000', $event->getValues()[0]['test']);
+        self::assertEquals('-51.1234', $event->getValues()[0]['test2']);
+        self::assertEquals('-51.123456789098765432123456789000', $event->getValues()[0]['test3']);
     }
 
     /**