Issue #1630568 by sokru, Laureatus, quietone, smustgrave, ravi.shankar:...

Issue #1630568 by sokru, Laureatus, quietone, smustgrave, ravi.shankar: Validate that uploaded .po files are UTF8

core/modules/file/src/Plugin/Validation/Constraint/FileEncodingConstraint.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\file\Plugin\Validation\Constraint;
+
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\Validation\Attribute\Constraint;
+use Symfony\Component\Validator\Constraint as SymfonyConstraint;
+
+/**
+ * Defines an encoding constraint for files.
+ */
+#[Constraint(
+  id: 'FileEncoding',
+  label: new TranslatableMarkup('File encoding', [], ['context' => 'Validation'])
+)]
+class FileEncodingConstraint extends SymfonyConstraint {
+
+  /**
+   * The error message.
+   *
+   * @var string
+   */
+  public string $message = "The file is encoded with %detected. It must be encoded with %encoding";
+
+  /**
+   * The allowed file encodings.
+   *
+   * @var array
+   */
+  public array $encodings;
+
+}

core/modules/file/src/Plugin/Validation/Constraint/FileEncodingConstraintValidator.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\file\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\Exception\UnexpectedTypeException;
+
+/**
+ * Validates the file encoding constraint.
+ */
+class FileEncodingConstraintValidator extends BaseFileConstraintValidator {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validate(mixed $value, Constraint $constraint): void {
+
+    /** @var \Drupal\file\Entity\FileInterface $file */
+    $file = $this->assertValueIsFile($value);
+    if (!$constraint instanceof FileEncodingConstraint) {
+      throw new UnexpectedTypeException($constraint, FileEncodingConstraint::class);
+    }
+
+    $encodings = $constraint->encodings;
+    $data = file_get_contents($file->getFileUri());
+    foreach ($encodings as $encoding) {
+      $this->validateEncoding($data, $encoding, $constraint);
+    }
+  }
+
+  /**
+   * Validates the encoding of the file.
+   *
+   * @param string $data
+   *   The file data.
+   * @param string $encoding
+   *   The encoding to validate.
+   * @param \Drupal\file\Plugin\Validation\Constraint\FileEncodingConstraint $constraint
+   *   The constraint.
+   */
+  protected function validateEncoding(string $data, string $encoding, FileEncodingConstraint $constraint): void {
+    if (mb_check_encoding($data, $encoding)) {
+      return;
+    }
+    $this->context->addViolation($constraint->message, [
+      '%encoding' => $encoding,
+      '%detected' => mb_detect_encoding($data),
+    ]);
+  }
+
+}

core/modules/file/tests/src/Kernel/Plugin/Validation/Constraint/FileEncodingConstraintValidatorTest.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\file\Kernel\Plugin\Validation\Constraint;
+
+use Drupal\file\Entity\File;
+use Drupal\Tests\file\Kernel\Validation\FileValidatorTestBase;
+
+// cspell:ignore räme
+
+/**
+ * Tests the FileEncodingConstraintValidator.
+ *
+ * @group file
+ * @coversDefaultClass \Drupal\file\Plugin\Validation\Constraint\FileEncodingConstraintValidator
+ */
+class FileEncodingConstraintValidatorTest extends FileValidatorTestBase {
+
+  /**
+   * Tests the FileEncodingConstraintValidator.
+   *
+   * @param array $file_properties
+   *   The properties of the file being validated.
+   * @param string[] $encodings
+   *   An array of the allowed file encodings.
+   * @param string[] $expected_errors
+   *   The expected error messages as string.
+   *
+   * @dataProvider providerTestFileValidateEncodings
+   * @covers ::validate
+   */
+  public function testFileEncodings(array $file_properties, array $encodings, array $expected_errors): void {
+    $data = 'Räme';
+    $data = mb_convert_encoding($data, $file_properties['encoding']);
+    file_put_contents($file_properties['uri'], $data);
+    $file = File::create($file_properties);
+    // Test for failure.
+    $validators = [
+      'FileEncoding' => [
+        'encodings' => $encodings,
+      ],
+    ];
+
+    $violations = $this->validator->validate($file, $validators);
+    $actual_errors = [];
+    foreach ($violations as $violation) {
+      $actual_errors[] = $violation->getMessage();
+    }
+    $this->assertEquals($expected_errors, $actual_errors);
+  }
+
+  /**
+   * Data provider for ::testFileEncoding.
+   *
+   * @return array[][]
+   *   The test cases.
+   */
+  public static function providerTestFileValidateEncodings(): array {
+    $utf8_encoded_txt_file_properties = [
+      'filename' => 'druplicon.txt',
+      'uri' => 'public://druplicon.txt',
+      'status' => 0,
+      'encoding' => 'UTF-8',
+    ];
+    $windows1252_encoded_txt_file = [
+      'filename' => 'druplicon-win.txt',
+      'uri' => 'public://druplicon-win.txt',
+      'status' => 1,
+      'encoding' => 'windows-1252',
+    ];
+    return [
+      'UTF-8 encoded file validated with "UTF-8" encoding' => [
+        'file_properties' => $utf8_encoded_txt_file_properties,
+        'encodings' => ['UTF-8'],
+        'expected_errors' => [],
+      ],
+      'Windows-1252 encoded file validated with "UTF-8" encoding' => [
+        'file_properties' => $windows1252_encoded_txt_file,
+        'encodings' => ['UTF-8'],
+        'expected_errors' => [
+          'The file is encoded with ASCII. It must be encoded with UTF-8',
+        ],
+      ],
+    ];
+  }
+
+  /**
+   * Helper function that returns a .po file with invalid encoding.
+   */
+  public function getInvalidEncodedPoFile() {
+    return <<< EOF
+msgid ""
+msgstr ""
+"Project-Id-Version: Drupal 8\\n"
+"MIME-Version: 1.0\\n"
+"Content-Type: text/plain; charset=Windows-1252\\n"
+"Content-Transfer-Encoding: 8bit\\n"
+"Plural-Forms: nplurals=2; plural=(n > 1);\\n"
+
+msgid "Swamp"
+msgstr "Räme"
+EOF;
+  }
+
+}

core/modules/locale/src/Form/ImportForm.php

@@ -101,6 +101,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     $validators = [
       'FileExtension' => ['extensions' => 'po'],
       'FileSizeLimit' => ['fileLimit' => Environment::getUploadMaxSize()],
+      'FileEncoding' => ['encodings' => ['UTF-8']],
     ];
     $form['file'] = [
       '#type' => 'file',

core/modules/locale/tests/src/Functional/LocaleImportFunctionalTest.php

@@ -11,7 +11,7 @@
 use Drupal\Tests\BrowserTestBase;
 
 // cspell:ignore chien chiens deutsch januari lundi montag moutons műveletek
-// cspell:ignore svibanj
+// cspell:ignore svibanj räme
 
 /**
  * Tests the import of locale files.
@@ -250,6 +250,9 @@ public function testStandalonePoFile(): void {
     $this->submitForm($search, 'Filter');
     $this->assertSession()->pageTextNotContains('No strings available.');
 
+    // Try importing a .po file with invalid encoding.
+    $this->importPoFile($this->getInvalidEncodedPoFile(), [], ['Windows-1252']);
+    $this->assertSession()->pageTextContains('The file is encoded with ASCII. It must be encoded with UTF-8');
   }
 
   /**
@@ -402,10 +405,15 @@ public function testCreatedLanguageTranslation(): void {
    *   Contents of the .po file to import.
    * @param array $options
    *   (optional) Additional options to pass to the translation import form.
+   * @param array $encodings
+   *   (optional) The encoding of the file.
    */
-  public function importPoFile($contents, array $options = []) {
+  public function importPoFile($contents, array $options = [], array $encodings = []) {
     $file_system = \Drupal::service('file_system');
     $name = $file_system->tempnam('temporary://', "po_") . '.po';
+    foreach ($encodings as $encoding) {
+      $contents = mb_convert_encoding($contents, $encoding);
+    }
     file_put_contents($name, $contents);
     $options['files[file]'] = $name;
     $this->drupalGet('admin/config/regional/translate/import');
@@ -672,6 +680,24 @@ public function getPoFileWithConfigDe() {
 msgid "German"
 msgstr "Deutsch"
 
+EOF;
+  }
+
+  /**
+   * Helper function that returns a .po file with invalid encoding.
+   */
+  public function getInvalidEncodedPoFile() {
+    return <<< EOF
+msgid ""
+msgstr ""
+"Project-Id-Version: Drupal 8\\n"
+"MIME-Version: 1.0\\n"
+"Content-Type: text/plain; charset=Windows-1252\\n"
+"Content-Transfer-Encoding: 8bit\\n"
+"Plural-Forms: nplurals=2; plural=(n > 1);\\n"
+
+msgid "Swamp"
+msgstr "Räme"
 EOF;
   }