Review fixes and additional comments in test

CHANGELOG.md

@@ -26,18 +26,8 @@ at anytime.
   * `get` failing with a non-useful error message when given a uri for a channel claim
   * exception checking in several wallet unit tests
   * daemon not erring properly for non-numeric values being passed to the `bid` parameter for the `publish` method
+  * `publish` command to allow updating claims with a `bid` amount higher than the wallet balance, so long as the amount is less than the wallet balance plus the bid amount of the claim being updated (https://github.com/lbryio/lbry/issues/748)
   * 
-  * Fixed unnecessarily verbose exchange rate error (https://github.com/lbryio/lbry/issues/984)
-  * Merged two separate dht test folders into one
-  * Fixed value error due to a race condition when saving to the claim cache (https://github.com/lbryio/lbry/issues/1013)
-  * Fixed being unable to re-download updated content (#951)
-  * Fixed sending error messages for failed api requests
-  * Fixed the file manager startup being slow when handling thousands of files
-  * Fixed handling decryption error for blobs encrypted with an invalid key
-  * Fixed handling stream with no data blob (https://github.com/lbryio/lbry/issues/905)
-  * Fixed fetching the external ip
-  * Fixed API call to blob_list with --uri parameter (https://github.com/lbryio/lbry/issues/895)
-  * Fixed publish command to allow updating claims with bid amount higher than wallet balance(by spending the claimtrietx coin) (https://github.com/lbryio/lbry/issues/748)
 
 ### Deprecated
   * `channel_list_mine`, replaced with `channel_list`

lbrynet/core/Wallet.py

@@ -768,6 +768,9 @@ class Wallet(object):
     def encrypt_wallet(self, new_password, update_keyring=False):
         return defer.fail(NotImplementedError())
 
+    def get_max_usable_balance_for_claim(self, claim_name):
+        return defer.fail(NotImplementedError())
+
     def _start(self):
         return defer.fail(NotImplementedError())
 
@@ -976,10 +979,8 @@ class LBRYumWallet(Wallet):
             lambda result: Decimal(result['confirmed']) + Decimal(result.get('unconfirmed', 0.0)))
         return d
 
-    @defer.inlineCallbacks
     def get_max_usable_balance_for_claim(self, claim_name):
-        amt = yield self._run_cmd_as_defer_to_thread('get_max_spendable_amt_for_claim', claim_name)
-        defer.returnValue(amt)
+        return self._run_cmd_as_defer_to_thread('get_max_spendable_amount_for_claim', claim_name)
 
     # Always create and return a brand new address
     def get_new_address(self, for_change=False, account=None):

lbrynet/daemon/Daemon.py

@@ -93,6 +93,7 @@ CONNECTION_MESSAGES = {
 }
 
 SHORT_ID_LEN = 20
+MAX_UPDATE_FEE_ESTIMATE = 0.3
 
 
 class IterableContainer(object):
@@ -2008,8 +2009,8 @@ class Daemon(AuthJSONRPCServer):
         amt = yield self.session.wallet.get_max_usable_balance_for_claim(name)
         if bid > amt:
             raise InsufficientFundsError(
-                "Please lower the bid value, the max amount you can specify for this claim is {}"
-                .format(amt))
+                "Please lower the bid value, the maximum amount you can specify for this claim is {}"
+                .format(amt - MAX_UPDATE_FEE_ESTIMATE))
 
         metadata = metadata or {}
         if fee is not None:

lbrynet/tests/unit/core/test_Wallet.py

@@ -37,7 +37,7 @@ test_claim_dict = {
 
 
 class MocLbryumWallet(LBRYumWallet):
-    def __init__(self, db_dir):
+    def __init__(self, db_dir, max_usable_balance=3):
         LBRYumWallet.__init__(self, SQLiteStorage(db_dir), SimpleConfig(
             {"lbryum_path": db_dir, "wallet_path": os.path.join(db_dir, "testwallet")}
         ))
@@ -46,6 +46,7 @@ class MocLbryumWallet(LBRYumWallet):
         self.total_reserved_points = Decimal(0.0)
         self.queued_payments = defaultdict(Decimal)
         self.network = FakeNetwork()
+        self._mock_max_usable_balance = max_usable_balance
         assert self.config.get_wallet_path() == os.path.join(self.db_dir, "testwallet")
 
     @defer.inlineCallbacks
@@ -74,7 +75,9 @@ class MocLbryumWallet(LBRYumWallet):
         return defer.succeed(True)
 
     def get_max_usable_balance_for_claim(self, name):
-        return defer.succeed(3)
+        # The amount is returned on the basis of test_point_reservation_and_claim unittest
+        # Also affects test_successful_send_name_claim
+        return defer.succeed(self._mock_max_usable_balance)
 
 class WalletTest(unittest.TestCase):
     @defer.inlineCallbacks