An empty string is a valid encoded result

Signed-off-by: Julius Härtl <jus@bitgrid.net>

3 files changed, 4 insertions, 3 deletions

diff --git a/lib/Service/ApiService.php b/lib/Service/ApiService.php
index 5ed1b3e79..651b1eefc 100644
--- a/lib/Service/ApiService.php
+++ b/lib/Service/ApiService.php
@@ -111,7 +111,7 @@ class ApiService {
 			$content = $baseFile->getContent();
 
 			$content = $this->encodingService->encodeToUtf8($content);
-			if (!$content) {
+			if ($content === null) {
 				$this->logger->log(ILogger::WARN, 'Failed to encode file to UTF8. File ID: ' . $file->getId());
 			}
 		} catch (NotFoundException $e) {
diff --git a/lib/Service/EncodingService.php b/lib/Service/EncodingService.php
index 3f5bada06..5026cd9a3 100644
--- a/lib/Service/EncodingService.php
+++ b/lib/Service/EncodingService.php
@@ -42,7 +42,8 @@ class EncodingService {
 			return null;
 		}
 
-		return mb_convert_encoding($string, 'UTF-8', $encoding);
+		$encoded = mb_convert_encoding($string, 'UTF-8', $encoding);
+		return is_string($encoded) ? $encoded : null;
 	}
 
 	public function detectEncoding(string $string): ?string {
diff --git a/lib/TextFile.php b/lib/TextFile.php
index 30b58c84c..9d632dcfe 100644
--- a/lib/TextFile.php
+++ b/lib/TextFile.php
@@ -63,7 +63,7 @@ class TextFile implements ISimpleFile {
 
 	public function getContent() {
 		$content = $this->encodingService->encodeToUtf8($this->file->getContent());
-		if (!$content) {
+		if ($content === null) {
 			throw new NotFoundException('File not compatible with text because it could not be encoded to UTF-8.');
 		}