bug #28228 [Validator] Fix precision issue regarding floats and Divis…

…ibleBy constraint (apfelbox)

This PR was merged into the 4.2-dev branch.

Discussion
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[Validator] Fix precision issue regarding floats and DivisibleBy constraint

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Alternative to #28212

Commits
-------

ae04b48 [Validator] Fix precision issue regarding floats and DivisibleBy constraint

src/Symfony/Component/Validator/Constraints/DivisibleByValidator.php

@@ -23,7 +23,17 @@ class DivisibleByValidator extends AbstractComparisonValidator
      */
     protected function compareValues($value1, $value2)
     {
-        return (float) 0 === fmod($value1, $value2);
+        if (!$value2 = abs($value2)) {
+            return false;
+        }
+        if (\is_int($value1 = abs($value1)) && \is_int($value2)) {
+            return 0 === ($value1 % $value2);
+        }
+        if (!$remainder = fmod($value1, $value2)) {
+            return true;
+        }
+
+        return sprintf('%.12e', $value2) === sprintf('%.12e', $remainder);
     }
 
     /**

src/Symfony/Component/Validator/Tests/Constraints/DivisibleByValidatorTest.php

@@ -46,6 +46,8 @@ public function provideValidComparisons()
             array(42, 21),
             array(3.25, 0.25),
             array('100', '10'),
+            array(4.1, 0.1),
+            array(-4.1, 0.1),
         );
     }
 
@@ -69,6 +71,7 @@ public function provideInvalidComparisons()
             array(10, '10', 3, '3', 'integer'),
             array(10, '10', 0, '0', 'integer'),
             array(42, '42', INF, 'INF', 'double'),
+            array(4.15, '4.15', 0.1, '0.1', 'double'),
             array('22', '"22"', '10', '"10"', 'string'),
         );
     }