From 1eabc0da092cedad98ebc133c3a2e8a46df9cff8 Mon Sep 17 00:00:00 2001
From: Joas Schilling <coding@schilljs.com>
Date: Wed, 15 May 2024 23:38:24 +0200
Subject: [PATCH] fix: Extend SVG reference check

Signed-off-by: Joas Schilling <coding@schilljs.com>
---
 lib/private/Preview/SVG.php   |  2 +-
 tests/lib/Preview/SVGTest.php | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/lib/private/Preview/SVG.php b/lib/private/Preview/SVG.php
index 690a6b50ffe74..094c96b271a96 100644
--- a/lib/private/Preview/SVG.php
+++ b/lib/private/Preview/SVG.php
@@ -53,7 +53,7 @@ public function getThumbnail(File $file, int $maxX, int $maxY): ?IImage {
 			}
 
 			// Do not parse SVG files with references
-			if (stripos($content, 'xlink:href') !== false) {
+			if (preg_match('/["\s](xlink:)?href\s*=/i', $content)) {
 				return null;
 			}
 
diff --git a/tests/lib/Preview/SVGTest.php b/tests/lib/Preview/SVGTest.php
index e48018a301b17..07e96eec9ab65 100644
--- a/tests/lib/Preview/SVGTest.php
+++ b/tests/lib/Preview/SVGTest.php
@@ -43,4 +43,33 @@ protected function setUp(): void {
 			$this->markTestSkipped('No SVG provider present');
 		}
 	}
+
+	public function dataGetThumbnailSVGHref(): array {
+		return [
+			['href'],
+			[' href'],
+			["\nhref"],
+			['xlink:href'],
+			[' xlink:href'],
+			["\nxlink:href"],
+		];
+	}
+
+	/**
+	 * @dataProvider dataGetThumbnailSVGHref
+	 * @requires extension imagick
+	 */
+	public function testGetThumbnailSVGHref(string $content): void {
+		$handle = fopen('php://temp', 'w+');
+		fwrite($handle, '<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+  <image x="0" y="0"' . $content . '="fxlogo.png" height="100" width="100" />
+</svg>');
+		rewind($handle);
+
+		$file = $this->createMock(\OCP\Files\File::class);
+		$file->method('fopen')
+			->willReturn($handle);
+
+		self::assertNull($this->provider->getThumbnail($file, 512, 512));
+	}
 }