fix an issue with large work counts...

My testing machine has 10 cpus, and so didn't trigger the failure
where not all the work was submitted..  We need to pop the completed
work items, and keep doing the for loop while we have futures to
process...  this submits and processes all work..

ui/medashare/btv/__init__.py

@@ -275,20 +275,21 @@ def validate(torrent, basedir, with_file_hashes=None):
 
 			futures[fut] = num, hash, i
 
-		for i in range(min(len(pending_work), os.cpu_count() + 1)):
+		for i in range(min(len(pending_work), os.cpu_count() + 2)):
 			submit_work(*pending_work.pop(0))
 
-		for future in concurrent.futures.as_completed(futures):
-			if pending_work:
-				submit_work(*pending_work.pop(0))
+		while futures:
+			for future in concurrent.futures.as_completed(futures):
+				if pending_work:
+					submit_work(*pending_work.pop(0))
 
-			future.result()
-			num, hash, i = futures[future]
+				future.result()
+				num, hash, i = futures.pop(future)
 
-			if hash.digest() == i:
-				valid[num] = True
-			else:
-				valid[num] = False
+				if hash.digest() == i:
+					valid[num] = True
+				else:
+					valid[num] = False
 
 	if files is None:
 		filesizes = { pathlib.PurePosixPath(info['name'].decode(
@@ -448,7 +449,8 @@ class _TestCases(unittest.TestCase):
 			    list(origrglob(pathlib.PosixPath('.'), 'somedir'))
 
 		with unittest.mock.patch.object(pathlib.PosixPath, 'rglob',
-		    side_effect=_rglob_patch):
+		    side_effect=_rglob_patch), unittest.mock.patch.object(os,
+		    'cpu_count', side_effect=lambda: 3):
 			good, bad = validate_file(tf)
 
 		self.assertFalse(bad)
@@ -512,7 +514,7 @@ class _TestCases(unittest.TestCase):
 		with open(sd / '40plus1.txt', 'w') as fp:
 			fp.write('w')
 
-		good, bad, hashes = validate_file(tor, with_file_hashes=sha512)
+			good, bad, hashes = validate_file(tor, with_file_hashes=sha512)
 
 		self.assertEqual(bad, { sd / '40plus1.txt' })
 		self.assertFalse(good)