fixup! Merge pull request #55582 from nextcloud/jtr/chore-app-encryption-desc

Author: artonge

lib/private/Files/ObjectStore/S3ObjectTrait.php

@@ -222,8 +222,20 @@ public function writeObjectWithMetaData(string $urn, $stream, array $metaData):
 				// buffer is fully seekable, so use it directly for the small upload
 				$this->writeSingle($urn, $buffer, $metaData);
 			} else {
-				$psrStream->rewind();
-				$this->writeMultiPart($urn, $psrStream, $metaData);
+				if ($psrStream->isSeekable()) {
+					// If the body is seekable, just rewind the body.
+					$psrStream->rewind();
+					$loadStream = $psrStream;
+				} else {
+					// If the body is non-seekable, stitch the rewind the buffer and
+					// the partially read body together into one stream. This avoids
+					// unnecessary disc usage and does not require seeking on the
+					// original stream.
+					$buffer->rewind();
+					$loadStream = new Psr7\AppendStream([$buffer, $psrStream]);
+				}
+
+				$this->writeMultiPart($urn, $loadStream, $metaData);
 			}
 		} else {
 			if ($size < $this->putSizeLimit) {