[10.x] Improve decimal shape validation (#47954)

* improve decimal shape validation

* Additional tests

Author: timacdonald

src/Illuminate/Validation/Concerns/ValidatesAttributes.php

@@ -599,7 +599,9 @@ public function validateDecimal($attribute, $value, $parameters)
 
         $matches = [];
 
-        preg_match('/^[+-]?\d*.(\d*)$/', $value, $matches);
+        if (preg_match('/^[+-]?\d*\.?(\d*)$/', $value, $matches) !== 1) {
+            return false;
+        }
 
         $decimals = strlen(end($matches));
 

tests/Validation/ValidationValidatorTest.php

@@ -2860,6 +2860,50 @@ public function testValidateDecimal()
 
         $v = new Validator($trans, ['foo' => '1.88888888888888888888'], ['foo' => 'Decimal:20|Max:1.88888888888888888888']);
         $this->assertTrue($v->passes());
+
+        $v = new Validator($trans, [
+            // these are the same number
+            'decimal' => '0.555',
+            'scientific' => '5.55e-1',
+        ], [
+            'decimal' => 'Decimal:0,2',
+            'scientific' => 'Decimal:0,2',
+        ]);
+        $this->assertSame(['decimal', 'scientific'], $v->errors()->keys());
+
+        $v = new Validator($trans, [
+            // these are the same number
+            'decimal' => '0.555',
+            'scientific' => '5.55e-1',
+        ], [
+            'decimal' => 'Decimal:0,3',
+            'scientific' => 'Decimal:0,3',
+        ]);
+        $this->assertSame(['scientific'], $v->errors()->keys());
+
+        $v = new Validator($trans, ['foo' => '+'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->fails());
+        $v = new Validator($trans, ['foo' => '-'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->fails());
+        $v = new Validator($trans, ['foo' => '10@12'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->fails());
+
+        $v = new Validator($trans, ['foo' => '+123'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->passes());
+        $v = new Validator($trans, ['foo' => '-123'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->passes());
+        $v = new Validator($trans, ['foo' => '+123.'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->passes());
+        $v = new Validator($trans, ['foo' => '-123.'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->passes());
+        $v = new Validator($trans, ['foo' => '123.'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->passes());
+        $v = new Validator($trans, ['foo' => '123.'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->passes());
+        $v = new Validator($trans, ['foo' => '123.34'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->passes());
+        $v = new Validator($trans, ['foo' => '123.34'], ['foo' => 'Decimal:0,2']);
+        $this->assertTrue($v->passes());
     }
 
     public function testValidateInt()