Merge pull request #20451 from exussum12/AllowPreviewWhenGeneratorHasBeenRemoved

Always try and show pre rendered preview

2 files changed, 77 insertions, 13 deletions

diff --git a/lib/private/Preview/Generator.php b/lib/private/Preview/Generator.php
index e47a7e5927c..d55aa1cb287 100644
--- a/lib/private/Preview/Generator.php
+++ b/lib/private/Preview/Generator.php
@@ -126,9 +126,6 @@ class Generator {
 		if ($mimeType === null) {
 			$mimeType = $file->getMimeType();
 		}
-		if (!$this->previewManager->isMimeSupported($mimeType)) {
-			throw new NotFoundException();
-		}
 
 		$previewFolder = $this->getPreviewFolder($file);
 
@@ -155,7 +152,7 @@ class Generator {
 			$crop = $specification['crop'] ?? false;
 			$mode = $specification['mode'] ?? IPreview::MODE_FILL;
 
-			// If both width and heigth are -1 we just want the max preview
+			// If both width and height are -1 we just want the max preview
 			if ($width === -1 && $height === -1) {
 				$width = $maxWidth;
 				$height = $maxHeight;
@@ -176,6 +173,10 @@ class Generator {
 				try {
 					$preview = $this->getCachedPreview($previewFolder, $width, $height, $crop, $maxPreview->getMimeType(), $previewVersion);
 				} catch (NotFoundException $e) {
+					if (!$this->previewManager->isMimeSupported($mimeType)) {
+						throw new NotFoundException();
+					}
+
 					if ($maxPreviewImage === null) {
 						$maxPreviewImage = $this->helper->getImage($maxPreview);
 					}
diff --git a/tests/lib/Preview/GeneratorTest.php b/tests/lib/Preview/GeneratorTest.php
index d2bfcad9955..43f5c1e0d36 100644
--- a/tests/lib/Preview/GeneratorTest.php
+++ b/tests/lib/Preview/GeneratorTest.php
@@ -256,25 +256,92 @@ class GeneratorTest extends \Test\TestCase {
 		$file = $this->createMock(File::class);
 		$file->method('isReadable')
 			->willReturn(true);
+		$file->method('getId')
+			->willReturn(42);
 
 		$this->previewManager->method('isMimeSupported')
 			->with('invalidType')
 			->willReturn(false);
 
+		$previewFolder = $this->createMock(ISimpleFolder::class);
+		$this->appData->method('getFolder')
+			->with($this->equalTo(42))
+			->willReturn($previewFolder);
+
+		$maxPreview = $this->createMock(ISimpleFile::class);
+		$maxPreview->method('getName')
+			->willReturn('2048-2048-max.png');
+		$maxPreview->method('getMimeType')
+			->willReturn('image/png');
+
+		$previewFolder->method('getDirectoryListing')
+			->willReturn([$maxPreview]);
+
+		$previewFolder->method('getFile')
+			->with($this->equalTo('1024-512-crop.png'))
+			->willThrowException(new NotFoundException());
+
+		$this->eventDispatcher->expects($this->once())
+			->method('dispatch')
+			->with(
+				$this->equalTo(IPreview::EVENT),
+				$this->callback(function (GenericEvent $event) use ($file) {
+					return $event->getSubject() === $file &&
+						$event->getArgument('width') === 1024 &&
+						$event->getArgument('height') === 512 &&
+						$event->getArgument('crop') === true &&
+						$event->getArgument('mode') === IPreview::MODE_COVER;
+				})
+			);
+
+		$this->generator->getPreview($file, 1024, 512, true, IPreview::MODE_COVER, 'invalidType');
+	}
+
+	public function testReturnCachedPreviewsWithoutCheckingSupportedMimetype() {
+		$file = $this->createMock(File::class);
+		$file->method('isReadable')
+			->willReturn(true);
+		$file->method('getId')
+			->willReturn(42);
+
+
+		$previewFolder = $this->createMock(ISimpleFolder::class);
+		$this->appData->method('getFolder')
+			->with($this->equalTo(42))
+			->willReturn($previewFolder);
+
+		$maxPreview = $this->createMock(ISimpleFile::class);
+		$maxPreview->method('getName')
+			->willReturn('2048-2048-max.png');
+		$maxPreview->method('getMimeType')
+			->willReturn('image/png');
+
+		$previewFolder->method('getDirectoryListing')
+			->willReturn([$maxPreview]);
+
+		$preview = $this->createMock(ISimpleFile::class);
+		$previewFolder->method('getFile')
+			->with($this->equalTo('1024-512-crop.png'))
+			->willReturn($preview);
+
+		$this->previewManager->expects($this->never())
+			->method('isMimeSupported');
+
 		$this->eventDispatcher->expects($this->once())
 			->method('dispatch')
 			->with(
 				$this->equalTo(IPreview::EVENT),
 				$this->callback(function (GenericEvent $event) use ($file) {
 					return $event->getSubject() === $file &&
-					$event->getArgument('width') === 0 &&
-					$event->getArgument('height') === 0 &&
-					$event->getArgument('crop') === true &&
-					$event->getArgument('mode') === IPreview::MODE_COVER;
+						$event->getArgument('width') === 1024 &&
+						$event->getArgument('height') === 512 &&
+						$event->getArgument('crop') === true &&
+						$event->getArgument('mode') === IPreview::MODE_COVER;
 				})
 			);
 
-		$this->generator->getPreview($file, 0, 0, true, IPreview::MODE_COVER, 'invalidType');
+		$result = $this->generator->getPreview($file, 1024, 512, true, IPreview::MODE_COVER, 'invalidType');
+		$this->assertSame($preview, $result);
 	}
 
 	public function testNoProvider() {
@@ -286,10 +353,6 @@ class GeneratorTest extends \Test\TestCase {
 		$file->method('getId')
 			->willReturn(42);
 
-		$this->previewManager->method('isMimeSupported')
-			->with($this->equalTo('myMimeType'))
-			->willReturn(true);
-
 		$previewFolder = $this->createMock(ISimpleFolder::class);
 		$this->appData->method('getFolder')
 			->with($this->equalTo(42))