From b403b05765897ed3d3c68e8e36f7ec82ea92658d Mon Sep 17 00:00:00 2001
From: Josh <josh.t.richards@gmail.com>
Date: Mon, 6 Jul 2026 11:06:15 -0400
Subject: [PATCH 1/3] perf(files_sharing): simplify tag population in
 ShareAPIController

Signed-off-by: Josh <josh.t.richards@gmail.com>
---
 .../lib/Controller/ShareAPIController.php     | 31 ++++++++++---------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/apps/files_sharing/lib/Controller/ShareAPIController.php b/apps/files_sharing/lib/Controller/ShareAPIController.php
index 64845f15cf541..36f5a1f33f7da 100644
--- a/apps/files_sharing/lib/Controller/ShareAPIController.php
+++ b/apps/files_sharing/lib/Controller/ShareAPIController.php
@@ -2227,29 +2227,30 @@ public function generateToken(): DataResponse {
 	 * @return list<T> file list populated with tags
 	 */
 	private function populateTags(array $fileList): array {
+		if ($fileList === []) {
+			return [];
+		}
+
 		$tagger = $this->tagManager->load('files');
-		$tags = $tagger->getTagsForObjects(array_map(static fn (array $fileData) => $fileData['file_source'], $fileList));
+		$tags = $tagger->getTagsForObjects(array_map(
+			static fn (array $fileData) => $fileData['file_source'],
+			$fileList
+		));
 
 		if (!is_array($tags)) {
 			throw new \UnexpectedValueException('$tags must be an array');
 		}
 
-		// Set empty tag array
-		foreach ($fileList as &$fileData) {
-			$fileData['tags'] = [];
+		$index = [];
+		foreach ($fileList as $i => $fileData) {
+			$fileList[$i]['tags'] = [];
+			// Multiple share rows can point to the same file_source, so store all positions.
+			$index[$fileData['file_source']][] = $i;
 		}
-		unset($fileData);
 
-		if (!empty($tags)) {
-			foreach ($tags as $fileId => $fileTags) {
-				foreach ($fileList as &$fileData) {
-					if ($fileId !== $fileData['file_source']) {
-						continue;
-					}
-
-					$fileData['tags'] = $fileTags;
-				}
-				unset($fileData);
+		foreach ($tags as $fileSource => $fileTags) {
+			foreach ($index[$fileSource] ?? [] as $i) {
+				$fileList[$i]['tags'] = $fileTags;
 			}
 		}
 

From 0fd8479d35b21572cd17ae06e856d884d8932d67 Mon Sep 17 00:00:00 2001
From: Josh <josh.t.richards@gmail.com>
Date: Mon, 6 Jul 2026 11:40:04 -0400
Subject: [PATCH 2/3] test(files_sharing): cover duplicate file_source entries
 in populateTags

Signed-off-by: Josh <josh.t.richards@gmail.com>
---
 .../Controller/ShareAPIControllerTest.php     | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/apps/files_sharing/tests/Controller/ShareAPIControllerTest.php b/apps/files_sharing/tests/Controller/ShareAPIControllerTest.php
index 097de4fa43740..984b0cb02c9d0 100644
--- a/apps/files_sharing/tests/Controller/ShareAPIControllerTest.php
+++ b/apps/files_sharing/tests/Controller/ShareAPIControllerTest.php
@@ -5257,6 +5257,31 @@ public function testPopulateTags(): void {
 		], $result);
 	}
 
+	public function testPopulateTagsWithDuplicateFileSource(): void {
+		$tagger = $this->createMock(ITags::class);
+		$this->tagManager->method('load')
+			->with('files')
+			->willReturn($tagger);
+		$data = [
+			['file_source' => 42, 'foo' => 'bar'],
+			['file_source' => 10],
+			['file_source' => 42, 'x' => 'y'],
+		];
+		$tags = [
+			42 => ['tag1', 'tag2'],
+		];
+		$tagger->method('getTagsForObjects')
+			->with([42, 10, 42])
+			->willReturn($tags);
+
+		$result = self::invokePrivate($this->ocs, 'populateTags', [$data]);
+		$this->assertSame([
+			['file_source' => 42, 'foo' => 'bar', 'tags' => ['tag1', 'tag2']],
+			['file_source' => 10, 'tags' => []],
+			['file_source' => 42, 'x' => 'y', 'tags' => ['tag1', 'tag2']],
+		], $result);
+	}
+
 	public static function trustedServerProvider(): array {
 		return [
 			'Trusted server' => [true, true],

From 8dec059db1c4fb2bede35d29fe7f1cf26904dc5f Mon Sep 17 00:00:00 2001
From: Josh <josh.t.richards@gmail.com>
Date: Tue, 7 Jul 2026 07:50:26 -0400
Subject: [PATCH 3/3] fix(files_sharing): adjust populateTags Psalm return type

Adjust the Psalm docblock for populateTags() to reflect the internal implementation change without changing the returned data shape.

Signed-off-by: Josh <josh.t.richards@gmail.com>
---
 apps/files_sharing/lib/Controller/ShareAPIController.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/apps/files_sharing/lib/Controller/ShareAPIController.php b/apps/files_sharing/lib/Controller/ShareAPIController.php
index 36f5a1f33f7da..b084691db72ca 100644
--- a/apps/files_sharing/lib/Controller/ShareAPIController.php
+++ b/apps/files_sharing/lib/Controller/ShareAPIController.php
@@ -2224,7 +2224,7 @@ public function generateToken(): DataResponse {
 	 *
 	 * @psalm-template T of array{tags?: list<string>, file_source: int, ...array<string, mixed>}
 	 * @param list<T> $fileList
-	 * @return list<T> file list populated with tags
+	 * @return list<T&array{tags: list<string>}> file list populated with tags
 	 */
 	private function populateTags(array $fileList): array {
 		if ($fileList === []) {