Fix some wrong behaviours due to rollbacks

doc/uml/tx_lifecycle.pu

-@startuml

note "With B a Block\nWith W the Median fork window\nWith Cur the current block of the main branch\nWith T a time" as N1
state Local_Tx {
 [*] --> To_send : Signed locally
 To_send : B = none
 To_send --> Awaiting : Node answered\n200 OK to POST
 Awaiting : Time = Cur.MedianTime
 Awaiting --> Refused : Not registered in [T; T+W*MedianTime]
 Refused --> To_send : Send back
 Refused --> [*] : Drop
}
state Registered {
 [*] --> Validating : Posted\nsin the blockchain
 Validating : B = Block containing the Tx
 Awaiting --> Validating : Found in the blockchain
 Validating --> Validated : Cur-B > W
 Validated --> Validating : Blockchain\nrollback
 Validated --> Awaiting : Blockchain\nrollback\ntx local removed
 Validated --> [*] : Blockchain\nrollback\ntx removed
 Validating --> [*] : Blockchain\nrollback\ntx removed
}

@enduml
\ No newline at end of file
+@startuml

note "With B a Block\nWith W the Median fork window\nWith Cur the current block of the main branch\nWith T a time" as N1
state Local_Tx {
 [*] --> To_send : Signed locally
 To_send : B = none
 To_send --> Awaiting : Node answered\n200 OK to POST
 Awaiting : Time = Cur.MedianTime
 Awaiting --> Refused : Not registered in [T; T+W*MedianTime]
 Refused --> To_send : Send back
 Refused --> [*] : Drop
}
state Registered {
 [*] --> Validating : Posted\nsin the blockchain
 Validating : B = Block containing the Tx
 Awaiting --> Validating : Found in the blockchain
 Validating --> Validated : Cur-B > W
 Validated --> Validating : Blockchain\nrollback\ntx in fork window
 Validated --> Awaiting : Blockchain\nrollback\ntx local removed
 Validated --> [*] : Blockchain\nrollback\ntx removed
 Validating --> [*] : Blockchain\nrollback\ntx removed
}

@enduml
\ No newline at end of file

src/cutecoin/core/app.py

@@ -252,6 +252,7 @@ class Application(QObject):
             self.accounts[account_name] = account
 
             for community in account.communities:
+                community.network.blockchain_rollback.connect(community.rollback_cache)
                 community.network.new_block_mined.connect(lambda b, co=community: account.refresh_transactions(self, co))
                 community.network.blockchain_rollback.connect(lambda b, co=community: account.rollback_transaction(self, co))
 

src/cutecoin/core/community.py

@@ -309,6 +309,9 @@ class Community(QObject):
     def stop_coroutines(self):
         self.network.stop_coroutines()
 
+    def rollback_cache(self):
+        self._bma_access.rollback()
+
     def jsonify(self):
         """
         Jsonify the community datas.

src/cutecoin/core/net/api/bma/access.py

@@ -165,6 +165,12 @@ class BmaAccess(QObject):
             return True
         return False
 
+    def rollback(self):
+        """
+        When a rollback is detected, we move the rollback cursor to 0
+        """
+        self._rollback_to = 0
+
     @asyncio.coroutine
     def future_request(self, request, req_args={}, get_args={}):
         """

src/cutecoin/core/transfer.py

@@ -88,9 +88,11 @@ class Transfer(QObject):
             (TransferState.VALIDATING, (bool, Block)):
                 ((self._rollback_and_removed, lambda r, b: self._drop(), TransferState.DROPPED),),
 
+            (TransferState.VALIDATED, (bool, Block, int)):
+                ((self._rollback_in_fork_window, lambda r, b: self._be_validating(b), TransferState.VALIDATING),),
+
             (TransferState.VALIDATED, (bool, Block)):
                 (
-                    (self._rollback_still_present, lambda r, b: self._be_validating(b), TransferState.VALIDATING),
                     (self._rollback_and_removed, lambda r, b: self._drop(), TransferState.DROPPED),
                     (self._rollback_and_local, lambda r, b: self._wait(b), TransferState.AWAITING),
                 ),
@@ -227,15 +229,15 @@ class Transfer(QObject):
                 return self.sha_hash not in [t.sha_hash for t in block.transactions]
         return False
 
-    def _rollback_still_present(self, rollback, block):
+    def _rollback_in_fork_window(self, rollback, current_block, fork_window):
         """
         Check if the transfer is not in the block anymore
         :param bool rollback: True if we are in a rollback procedure
-        :param ucoinpy.documents.Block block: The block to check for the transaction
+        :param ucoinpy.documents.Block current_block: The block to check for the transaction
         :return: True if the transfer is found in the block
         """
-        if rollback and block.blockid == self.blockid:
-            return self.sha_hash in [t.sha_hash for t in block.transactions]
+        if rollback:
+            return self.blockid.number + fork_window > current_block.number
         return False
 
     def _rollback_and_local(self, rollback, block):

src/cutecoin/core/txhistory.py

@@ -74,6 +74,34 @@ class TxHistory():
     def stop_coroutines(self):
         self._stop_coroutines = True
 
+    def _get_block_doc(self, community, number):
+        """
+        Retrieve the current block document
+        :param cutecoin.core.Community community: The community we look for a block
+        :param int number: The block number to retrieve
+        :return: the block doc or None if no block was found
+        """
+        tries = 0
+        block_doc = None
+        block = None
+        while block is None and tries < 3:
+            try:
+                block = yield from community.bma_access.future_request(bma.blockchain.Block,
+                                      req_args={'number': number})
+                signed_raw = "{0}{1}\n".format(block['raw'],
+                                           block['signature'])
+                try:
+                    block_doc = Block.from_signed_raw(signed_raw)
+                except TypeError:
+                    logging.debug("Error in {0}".format(number))
+                    block = None
+                    tries += 1
+            except ValueError as e:
+                if '404' in str(e):
+                    block = None
+                    tries += 1
+        return block_doc
+
     @asyncio.coroutine
     def _parse_transaction(self, community, tx, blockid,
                            mediantime, received_list, txid):
@@ -153,36 +181,17 @@ class TxHistory():
         return None
 
     @asyncio.coroutine
-    def _parse_block(self, community, block_number, received_list, current_block, txmax):
+    def _parse_block(self, community, block_number, received_list, txmax):
         """
         Parse a block
         :param cutecoin.core.Community community: The community
         :param int block_number: The block to request
         :param list received_list: The list where we are appending transactions
-        :param int current_block: The current block of the network
         :param int txmax: Latest tx id
         :return: The list of transfers sent
         """
-        block = None
-        block_doc = None
-        tries = 0
-        while block is None and tries < 3:
-            try:
-                block = yield from community.bma_access.future_request(bma.blockchain.Block,
-                                      req_args={'number': block_number})
-                signed_raw = "{0}{1}\n".format(block['raw'],
-                                           block['signature'])
+        block_doc = yield from self._get_block_doc(community, block_number)
         transfers = []
-                try:
-                    block_doc = Block.from_signed_raw(signed_raw)
-                except TypeError:
-                    logging.debug("Error in {0}".format(block_number))
-                    block = None
-                    tries += 1
-            except ValueError as e:
-                if '404' in str(e):
-                    block = None
-                    tries += 1
         if block_doc:
             for transfer in [t for t in self._transfers if t.state == TransferState.AWAITING]:
                 transfer.run_state_transitions((False, block_doc))
@@ -259,7 +268,7 @@ class TxHistory():
                 # We parse only blocks with transactions
                 if block_number_from in blocks_with_tx:
                     transfers = yield from self._parse_block(community, block_number_from,
-                                                             received_list, block_to,
+                                                             received_list,
                                                              udid + len(new_transfers))
                     new_transfers += transfers
 
@@ -300,25 +309,9 @@ class TxHistory():
         :param cutecoin.core.Community community: The community
         :param int block_number: The block to check for transfers
         """
-        block = None
-        block_doc = None
-        tries = 0
-        while block is None and tries < 3:
-            try:
-                block = yield from community.bma_access.future_request(bma.blockchain.Block,
-                                      req_args={'number': block_number})
-                signed_raw = "{0}{1}\n".format(block['raw'],
-                                           block['signature'])
-                try:
-                    block_doc = Block.from_signed_raw(signed_raw)
-                except TypeError:
-                    logging.debug("Error in {0}".format(block_number))
-                    block = None
-                    tries += 1
-            except ValueError as e:
-                if '404' in str(e):
-                    block = None
-                    tries += 1
+        block_doc = yield from self._get_block_doc(community, block_number)
+
+        # We check if transactions are still present
         for transfer in [t for t in self._transfers
                          if t.state in (TransferState.VALIDATING, TransferState.VALIDATED) and
                          t.blockid.number == block_number]:
@@ -341,10 +334,19 @@ class TxHistory():
             tx_blocks = [tx.blockid.number for tx in self._transfers
                           if tx.state in (TransferState.VALIDATED, TransferState.VALIDATING) and
                           tx.blockid is not None]
+            tx_blocks.reverse()
             for i, block_number in enumerate(tx_blocks):
                 self.wallet.refresh_progressed.emit(i, len(tx_blocks), self.wallet.pubkey)
                 if (yield from self._check_block(community, block_number)):
-                    return
+                    break
+
+            current_block = yield from self._get_block_doc(community, community.network.current_blockid.number)
+            members_pubkeys = yield from community.members_pubkeys()
+            fork_window = community.network.fork_window(members_pubkeys)
+            # We check if transactions VALIDATED are in the fork window now
+            for transfer in [t for t in self._transfers
+                             if t.state == TransferState.VALIDATED]:
+                transfer.run_state_transitions((True, current_block, fork_window))
         except NoPeerAvailable:
             logging.debug("No peer available")