Make StreamWrapper::stream_stat() returns false if inner stream's…

… size is `null` (#594)

src/StreamWrapper.php

@@ -136,10 +136,14 @@ public function stream_cast(int $cast_as)
      *   ctime: int,
      *   blksize: int,
      *   blocks: int
-     * }
+     * }|false
      */
-    public function stream_stat(): array
+    public function stream_stat()
     {
+        if ($this->stream->getSize() === null) {
+            return false;
+        }
+
         static $modeMap = [
             'r' => 33060,
             'rb' => 33060,

tests/StreamWrapperTest.php

@@ -6,6 +6,7 @@
 
 use GuzzleHttp\Psr7;
 use GuzzleHttp\Psr7\StreamWrapper;
+use GuzzleHttp\Psr7\Utils;
 use PHPUnit\Framework\TestCase;
 use Psr\Http\Message\StreamInterface;
 
@@ -187,4 +188,15 @@ public function testXmlWriterWithStream(): void
         $stream->rewind();
         self::assertXmlStringEqualsXmlString('<?xml version="1.0"?><foo />', (string) $stream);
     }
+
+    public function testWrappedNullSizedStreamStaysNullSized(): void
+    {
+        $nullSizedStream = new Psr7\PumpStream(function () { return ''; });
+        $this->assertNull($nullSizedStream->getSize());
+
+        $resource = StreamWrapper::getResource($nullSizedStream);
+        $stream = Utils::streamFor($resource);
+
+        $this->assertNull($stream->getSize());
+    }
 }