[5.3] Backport fixes for image validation (#17983)

* Suppress getimagesize() warnings

Backport of #17944.

`getimagesize` will fail with a notice on files smaller than 12 bytes.
This ends up becoming an ErrorException which is pretty annoying.

Suppressing the warning is enough to still end up with a `false` result
which will fail the validation gracefully instead of grueing up your
stew.

* Proper float comparison in ratio validation

* Convert fixtures to PNG format

* Add test for validation of ratio with no fractional part

src/Illuminate/Validation/Validator.php

@@ -1661,7 +1661,7 @@ protected function validateImage($attribute, $value)
      */
     protected function validateDimensions($attribute, $value, $parameters)
     {
-        if (! $this->isAValidFileInstance($value) || ! $sizeDetails = getimagesize($value->getRealPath())) {
+        if (! $this->isAValidFileInstance($value) || ! $sizeDetails = @getimagesize($value->getRealPath())) {
             return false;
         }
 
@@ -1687,7 +1687,7 @@ protected function validateDimensions($attribute, $value, $parameters)
                 [1, 1], array_filter(sscanf($parameters['ratio'], '%f/%d'))
             );
 
-            return $numerator / $denominator == $width / $height;
+            return abs($numerator / $denominator - $width / $height) < 0.000001;
         }
 
         return true;

tests/Validation/ValidationValidatorTest.php

@@ -1855,8 +1855,8 @@ public function testValidateImage()
 
     public function testValidateImageDimensions()
     {
-        // Knowing that demo image.gif has width = 3 and height = 2
-        $uploadedFile = new \Symfony\Component\HttpFoundation\File\UploadedFile(__DIR__.'/fixtures/image.gif', '', null, null, null, true);
+        // Knowing that demo image.png has width = 3 and height = 2
+        $uploadedFile = new \Symfony\Component\HttpFoundation\File\UploadedFile(__DIR__.'/fixtures/image.png', '', null, null, null, true);
         $trans = $this->getIlluminateArrayTranslator();
 
         $v = new Validator($trans, ['x' => 'file'], ['x' => 'dimensions']);
@@ -1903,6 +1903,21 @@ public function testValidateImageDimensions()
 
         $v = new Validator($trans, ['x' => $uploadedFile], ['x' => 'dimensions:ratio=1']);
         $this->assertTrue($v->fails());
+
+        // This test fails without suppressing warnings on getimagesize() due to a read error.
+        $emptyUploadedFile = new \Symfony\Component\HttpFoundation\File\UploadedFile(__DIR__.'/fixtures/empty.png', '', null, null, null, true);
+        $trans = $this->getIlluminateArrayTranslator();
+
+        $v = new Validator($trans, ['x' => $emptyUploadedFile], ['x' => 'dimensions:min_width=1']);
+        $this->assertTrue($v->fails());
+
+        // Knowing that demo image2.png has width = 4 and height = 2
+        $uploadedFile = new \Symfony\Component\HttpFoundation\File\UploadedFile(__DIR__.'/fixtures/image2.png', '', null, null, null, true);
+        $trans = $this->getIlluminateArrayTranslator();
+
+        // Ensure validation doesn't erroneously fail when ratio has no fractional part
+        $v = new Validator($trans, ['x' => $uploadedFile], ['x' => 'dimensions:ratio=2/1']);
+        $this->assertTrue($v->passes());
     }
 
     /**