Document Security - Coverage, Testing, and Bug-fixing (#2128)

Having a parallel project to complete cover Document Properties, I turned my attention to to Document Security. As happens, this particular change grew a bit over time.

Coverage and Testing Changes:
- Since the Security object has no members which are themselves objects, there is no need for a deep clone. The untested __clone method is removed.
- Almost all of the coverage for the Security Object came about through samples 11 and 41, not through formal tests with assertions. Formal tests have been added.
- All methods now use type-hinting via the function signature rather than doc block.
- Coverage is now 100%.

<!-- end of coverage and testing changes list -->

Bug:
- Xlsx Reader was not evaluating the Lock values correctly. This revelation came as a result of the new tests ...
- Which showed that Xlsx Reader was testing SimpleXmlElement as a boolean rather than the stringified version of that ...
- Which didn't matter all that much because Xlsx Writer was writing the values as 'true' or 'false' rather than '1' or '0', and (bool) 'false' is true.
- Xlsx Reader clearly needed a change. I was trying to avoid that while awaiting the namespacing change. At least this is restricted to a very small self-contained piece of the code.
- It is less clear whether Xlsx Writer should be changed. It is true that Excel itself uses 1/0 when writing; however it is equally true that it recognizes true/false as well as 1/0 when reading. For now, I have left Xlsx Writer alone to limit the change to what is absolutely needed.

<!-- end of bug list -->

Other Changes:
- I was at a complete loss as to what "lock revisions" was supposed to do, and it took a while to find anything on the web that explained it. Thank you, openpyxl, for coming through. I have documented it for PhpSpreadsheet now.

<!-- end of other changes list -->

Miscellaneous Note:
- There remains no support for Document Security in Xls Reader or Writer (nor in any of the other readers/writers except Xlsx).
- No Phpstan baseline changes, possibly for the first time in any of my PRs since Phpstan was introduced.

Co-authored-by: Mark Baker <mark@lange.demon.co.uk>

tests/PhpSpreadsheetTests/Document/SecurityTest.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Document;
+
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
+
+class SecurityTest extends AbstractFunctional
+{
+    public function testSecurity(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $spreadsheet->getActiveSheet()->getCell('A1')->setValue('Hello');
+        $security = $spreadsheet->getSecurity();
+        $security->setLockRevision(true);
+        $revisionsPassword = 'revpasswd';
+        $security->setRevisionsPassword($revisionsPassword);
+        $hashedRevisionsPassword = $security->getRevisionsPassword();
+        self::assertNotEquals($revisionsPassword, $hashedRevisionsPassword);
+        $security->setLockWindows(true);
+        $security->setLockStructure(true);
+        $workbookPassword = 'wbpasswd';
+        $security->setWorkbookPassword($workbookPassword);
+        $hashedWorkbookPassword = $security->getWorkbookPassword();
+        self::assertNotEquals($workbookPassword, $hashedWorkbookPassword);
+
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx');
+        $reloadedSecurity = $reloadedSpreadsheet->getSecurity();
+        self::assertTrue($reloadedSecurity->getLockRevision());
+        self::assertTrue($reloadedSecurity->getLockWindows());
+        self::assertTrue($reloadedSecurity->getLockStructure());
+        self::assertSame($hashedWorkbookPassword, $reloadedSecurity->getWorkbookPassword());
+        self::assertSame($hashedRevisionsPassword, $reloadedSecurity->getRevisionsPassword());
+
+        $reloadedSecurity->setRevisionsPassword($hashedWorkbookPassword, true);
+        self::assertSame($hashedWorkbookPassword, $reloadedSecurity->getRevisionsPassword());
+        $reloadedSecurity->setWorkbookPassword($hashedRevisionsPassword, true);
+        self::assertSame($hashedRevisionsPassword, $reloadedSecurity->getWorkbookPassword());
+    }
+
+    public function providerLocks(): array
+    {
+        return [
+            [false, false, false],
+            [false, false, true],
+            [false, true, false],
+            [false, true, true],
+            [true, false, false],
+            [true, false, true],
+            [true, true, false],
+            [true, true, true],
+        ];
+    }
+
+    /**
+     * @dataProvider providerLocks
+     */
+    public function testLocks(bool $revision, bool $windows, bool $structure): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $spreadsheet->getActiveSheet()->getCell('A1')->setValue('Hello');
+        $security = $spreadsheet->getSecurity();
+        $security->setLockRevision($revision);
+        $security->setLockWindows($windows);
+        $security->setLockStructure($structure);
+        $enabled = $security->isSecurityEnabled();
+        self::assertSame($enabled, $revision || $windows || $structure);
+
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx');
+        $reloadedSecurity = $reloadedSpreadsheet->getSecurity();
+        self::assertSame($revision, $reloadedSecurity->getLockRevision());
+        self::assertSame($windows, $reloadedSecurity->getLockWindows());
+        self::assertSame($structure, $reloadedSecurity->getLockStructure());
+    }
+}