diff --git a/res/composer-schema.json b/res/composer-schema.json
index f636fc9f5..1d99030ff 100644
--- a/res/composer-schema.json
+++ b/res/composer-schema.json
@@ -132,6 +132,12 @@
                 }
             }
         },
+        "source": {
+            "$ref": "#/definitions/source"
+        },
+        "dist": {
+            "$ref": "#/definitions/dist"
+        },
         "_comment": {
             "type": ["array", "string"],
             "description": "A key to store comments in"
@@ -953,46 +959,52 @@
                     }
                 },
                 "source": {
-                    "type": "object",
-                    "required": ["type", "url", "reference"],
-                    "properties": {
-                        "type": {
-                            "type": "string"
-                        },
-                        "url": {
-                            "type": "string"
-                        },
-                        "reference": {
-                            "type": "string"
-                        },
-                        "mirrors": {
-                            "type": "array"
-                        }
-                    }
+                    "$ref": "#/definitions/source"
                 },
                 "dist": {
-                    "type": "object",
-                    "required": ["type", "url"],
-                    "properties": {
-                        "type": {
-                            "type": "string"
-                        },
-                        "url": {
-                            "type": "string"
-                        },
-                        "reference": {
-                            "type": "string"
-                        },
-                        "shasum": {
-                            "type": "string"
-                        },
-                        "mirrors": {
-                            "type": "array"
-                        }
-                    }
+                    "$ref": "#/definitions/dist"
                 }
             },
             "additionalProperties": true
+        },
+        "source": {
+            "type": "object",
+            "required": ["type", "url", "reference"],
+            "properties": {
+                "type": {
+                    "type": "string"
+                },
+                "url": {
+                    "type": "string"
+                },
+                "reference": {
+                    "type": "string"
+                },
+                "mirrors": {
+                    "type": "array"
+                }
+            }
+        },
+        "dist": {
+            "type": "object",
+            "required": ["type", "url"],
+            "properties": {
+                "type": {
+                    "type": "string"
+                },
+                "url": {
+                    "type": "string"
+                },
+                "reference": {
+                    "type": "string"
+                },
+                "shasum": {
+                    "type": "string"
+                },
+                "mirrors": {
+                    "type": "array"
+                }
+            }
         }
     }
 }
diff --git a/src/Composer/Downloader/ArchiveDownloader.php b/src/Composer/Downloader/ArchiveDownloader.php
index 50c00ac24..6c01e947f 100644
--- a/src/Composer/Downloader/ArchiveDownloader.php
+++ b/src/Composer/Downloader/ArchiveDownloader.php
@@ -114,7 +114,9 @@ abstract class ArchiveDownloader extends FileDownloader
         }
 
         return $promise->then(function () use ($package, $filesystem, $fileName, $temporaryDir, $path): \React\Promise\PromiseInterface {
-            $filesystem->unlink($fileName);
+            if (file_exists($fileName)) {
+                $filesystem->unlink($fileName);
+            }
 
             /**
              * Returns the folder content, excluding .DS_Store
diff --git a/src/Composer/Downloader/ZipDownloader.php b/src/Composer/Downloader/ZipDownloader.php
index f04007d3b..1feec5b4d 100644
--- a/src/Composer/Downloader/ZipDownloader.php
+++ b/src/Composer/Downloader/ZipDownloader.php
@@ -179,7 +179,12 @@ class ZipDownloader extends ArchiveDownloader
         $zipArchive = $this->zipArchiveObject ?: new ZipArchive();
 
         try {
-            if (true === ($retval = $zipArchive->open($file))) {
+            if (!file_exists($file) || ($filesize = filesize($file)) === false || $filesize === 0) {
+                $retval = -1;
+            } else {
+                $retval = $zipArchive->open($file);
+            }
+            if (true === $retval) {
                 $extractResult = $zipArchive->extractTo($path);
 
                 if (true === $extractResult) {
@@ -241,6 +246,8 @@ class ZipDownloader extends ArchiveDownloader
                 return sprintf("Zip read error (%s)", $file);
             case ZipArchive::ER_SEEK:
                 return sprintf("Zip seek error (%s)", $file);
+            case -1:
+                return sprintf("'%s' is a corrupted zip archive (0 bytes), try again.", $file);
             default:
                 return sprintf("'%s' is not a valid zip archive, got error code: %s", $file, $retval);
         }
diff --git a/src/Composer/Repository/Vcs/GitBitbucketDriver.php b/src/Composer/Repository/Vcs/GitBitbucketDriver.php
index 30f35235f..be998f377 100644
--- a/src/Composer/Repository/Vcs/GitBitbucketDriver.php
+++ b/src/Composer/Repository/Vcs/GitBitbucketDriver.php
@@ -390,7 +390,7 @@ class GitBitbucketDriver extends VcsDriver
         } catch (TransportException $e) {
             $bitbucketUtil = new Bitbucket($this->io, $this->config, $this->process, $this->httpDownloader);
 
-            if (403 === $e->getCode() || (401 === $e->getCode() && strpos($e->getMessage(), 'Could not authenticate against') === 0)) {
+            if (in_array($e->getCode(), array(403, 404), true) || (401 === $e->getCode() && strpos($e->getMessage(), 'Could not authenticate against') === 0)) {
                 if (!$this->io->hasAuthentication($this->originUrl)
                     && $bitbucketUtil->authorizeOAuth($this->originUrl)
                 ) {
diff --git a/tests/Composer/Test/Downloader/ZipDownloaderTest.php b/tests/Composer/Test/Downloader/ZipDownloaderTest.php
index 9c6e7c05d..2d3e319ee 100644
--- a/tests/Composer/Test/Downloader/ZipDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/ZipDownloaderTest.php
@@ -32,6 +32,8 @@ class ZipDownloaderTest extends TestCase
     private $config;
     /** @var \Composer\Package\PackageInterface&\PHPUnit\Framework\MockObject\MockObject */
     private $package;
+    /** @var string */
+    private $filename;
 
     public function setUp(): void
     {
@@ -41,6 +43,9 @@ class ZipDownloaderTest extends TestCase
         $dlConfig = $this->getMockBuilder('Composer\Config')->getMock();
         $this->httpDownloader = new HttpDownloader($this->io, $dlConfig);
         $this->package = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
+
+        $this->filename = $this->testDir.'/composer-test.zip';
+        file_put_contents($this->filename, 'zip');
     }
 
     protected function tearDown(): void
@@ -126,7 +131,7 @@ class ZipDownloaderTest extends TestCase
             ->will($this->returnValue(false));
 
         $this->setPrivateProperty('zipArchiveObject', $zipArchive, $downloader);
-        $promise = $downloader->extract($this->package, 'testfile.zip', 'vendor/dir');
+        $promise = $downloader->extract($this->package, $this->filename, 'vendor/dir');
         $this->wait($promise);
     }
 
@@ -149,7 +154,7 @@ class ZipDownloaderTest extends TestCase
             ->will($this->throwException(new \ErrorException('Not a directory')));
 
         $this->setPrivateProperty('zipArchiveObject', $zipArchive, $downloader);
-        $promise = $downloader->extract($this->package, 'testfile.zip', 'vendor/dir');
+        $promise = $downloader->extract($this->package, $this->filename, 'vendor/dir');
         $this->wait($promise);
     }
 
@@ -170,7 +175,7 @@ class ZipDownloaderTest extends TestCase
             ->will($this->returnValue(true));
 
         $this->setPrivateProperty('zipArchiveObject', $zipArchive, $downloader);
-        $promise = $downloader->extract($this->package, 'testfile.zip', 'vendor/dir');
+        $promise = $downloader->extract($this->package, $this->filename, 'vendor/dir');
         $this->wait($promise);
     }
 
@@ -199,7 +204,7 @@ class ZipDownloaderTest extends TestCase
             ->will($this->returnValue(\React\Promise\resolve($procMock)));
 
         $downloader = new MockedZipDownloader($this->io, $this->config, $this->httpDownloader, null, null, null, $processExecutor);
-        $promise = $downloader->extract($this->package, 'testfile.zip', 'vendor/dir');
+        $promise = $downloader->extract($this->package, $this->filename, 'vendor/dir');
         $this->wait($promise);
     }
 
@@ -226,7 +231,7 @@ class ZipDownloaderTest extends TestCase
             ->will($this->returnValue(\React\Promise\resolve($procMock)));
 
         $downloader = new MockedZipDownloader($this->io, $this->config, $this->httpDownloader, null, null, null, $processExecutor);
-        $promise = $downloader->extract($this->package, 'testfile.zip', 'vendor/dir');
+        $promise = $downloader->extract($this->package, $this->filename, 'vendor/dir');
         $this->wait($promise);
     }
 
@@ -265,7 +270,7 @@ class ZipDownloaderTest extends TestCase
 
         $downloader = new MockedZipDownloader($this->io, $this->config, $this->httpDownloader, null, null, null, $processExecutor);
         $this->setPrivateProperty('zipArchiveObject', $zipArchive, $downloader);
-        $promise = $downloader->extract($this->package, 'testfile.zip', 'vendor/dir');
+        $promise = $downloader->extract($this->package, $this->filename, 'vendor/dir');
         $this->wait($promise);
     }
 
@@ -306,7 +311,7 @@ class ZipDownloaderTest extends TestCase
 
         $downloader = new MockedZipDownloader($this->io, $this->config, $this->httpDownloader, null, null, null, $processExecutor);
         $this->setPrivateProperty('zipArchiveObject', $zipArchive, $downloader);
-        $promise = $downloader->extract($this->package, 'testfile.zip', 'vendor/dir');
+        $promise = $downloader->extract($this->package, $this->filename, 'vendor/dir');
         $this->wait($promise);
     }