fix: Prevent NPE when bucket doesn't exit #857

Fixes a NullPointerException when creating a Path object with a bucket
that doesn't exist. This only occurred when autoDetectRequesterPays = true.

Refs: #857

google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/CloudStorageFileSystemProvider.java

@@ -963,8 +963,13 @@ public String toString() {
   public boolean requesterPays(String bucketName) {
     initStorage();
     try {
-      // instead of true/false, this method returns true/null.
-      Boolean isRP = storage.get(bucketName).requesterPays();
+      final Bucket bucket = storage.get(bucketName);
+      // If the bucket doesn't exist it can't be requester pays.
+      if (bucket == null) {
+        return false;
+      }
+      // instead of true/false, this method returns true/null
+      Boolean isRP = bucket.requesterPays();
       return isRP != null && isRP.booleanValue();
     } catch (StorageException ex) {
       if ("userProjectMissing".equals(ex.getReason())) {

google-cloud-nio/src/test/java/com/google/cloud/storage/contrib/nio/it/ITGcsNio.java

@@ -49,6 +49,7 @@
 import java.io.IOException;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
+import java.net.URISyntaxException;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.nio.channels.ReadableByteChannel;
@@ -327,6 +328,24 @@ public void testAutodetectWhenNotRequesterPays() throws IOException {
         "");
   }
 
+  @Test
+  public void assertNoCrashWhenBucketDoesntExist() throws URISyntaxException {
+    CloudStorageConfiguration config =
+        CloudStorageConfiguration.builder()
+            .autoDetectRequesterPays(true)
+            .userProject(project)
+            .usePseudoDirectories(true)
+            .build();
+
+    final String bucketThatDoesntExist = "abuckethatdoesntexist";
+    final String subPath = "hello";
+    CloudStorageFileSystem testBucket =
+        CloudStorageFileSystem.forBucket(bucketThatDoesntExist, config, storageOptions);
+    final CloudStoragePath aPathThatDoesntExist = testBucket.getPath(subPath);
+    Assert.assertEquals(
+        aPathThatDoesntExist.toUri().toString(), "gs://" + bucketThatDoesntExist + "/" + subPath);
+  }
+
   @Test
   public void testAutoDetectNoUserProject() throws IOException {
     CloudStorageFileSystem testBucket = getRequesterPaysBucket(false, "");