wallet_db: impl convert_version_33: put 'height' field into invoices

The 'height' field was added in https://github.com/spesmilo/electrum/commit/cdfaaa260942b807f809c2c0414fb242a03e945a
At the time we thought we could just add it with a default value without a db upgrade;
however the issue is that if old code tries to open a new db, it will fail (due to unexpected new field).
Hence it is better to do an explicit conversion where old code *knows* it cannot open the new db.

E | gui.qt.ElectrumGui |
Traceback (most recent call last):
  File "...\electrum\electrum\gui\qt\__init__.py", line 257, in start_new_window
    wallet = self.daemon.load_wallet(path, None)
  File "...\electrum\electrum\daemon.py", line 488, in load_wallet
    db = WalletDB(storage.read(), manual_upgrades=manual_upgrades)
  File "...\electrum\electrum\wallet_db.py", line 72, in __init__
    self.load_data(raw)
  File "...\electrum\electrum\wallet_db.py", line 103, in load_data
    self._after_upgrade_tasks()
  File "...\electrum\electrum\wallet_db.py", line 189, in _after_upgrade_tasks
    self._load_transactions()
  File "...\electrum\electrum\util.py", line 408, in <lambda>
    return lambda *args, **kw_args: do_profile(args, kw_args)
  File "...\electrum\electrum\util.py", line 404, in do_profile
    o = func(*args, **kw_args)
  File "...\electrum\electrum\wallet_db.py", line 1139, in _load_transactions
    self.data = StoredDict(self.data, self, [])
  File "...\electrum\electrum\json_db.py", line 79, in __init__
    self.__setitem__(k, v)
  File "...\electrum\electrum\json_db.py", line 44, in wrapper
    return func(self, *args, **kwargs)
  File "...\electrum\electrum\json_db.py", line 105, in __setitem__
    v = self.db._convert_dict(self.path, key, v)
  File "...\electrum\electrum\wallet_db.py", line 1182, in _convert_dict
    v = dict((k, Invoice.from_json(x)) for k, x in v.items())
  File "...\electrum\electrum\wallet_db.py", line 1182, in <genexpr>
    v = dict((k, Invoice.from_json(x)) for k, x in v.items())
  File "...\electrum\electrum\invoices.py", line 108, in from_json
    return OnchainInvoice(**x)
TypeError: __init__() got an unexpected keyword argument 'height'

electrum/invoices.py

@@ -118,7 +118,7 @@ class OnchainInvoice(Invoice):
     outputs = attr.ib(kw_only=True, converter=_decode_outputs)  # type: List[PartialTxOutput]
     bip70 = attr.ib(type=str, kw_only=True)  # type: Optional[str]
     requestor = attr.ib(type=str, kw_only=True)  # type: Optional[str]
-    height = attr.ib(type=int, default=0, kw_only=True, validator=attr.validators.instance_of(int))
+    height = attr.ib(type=int, kw_only=True, validator=attr.validators.instance_of(int))
 
     def get_address(self) -> str:
         """returns the first address, to be displayed in GUI"""

electrum/wallet_db.py

@@ -52,7 +52,7 @@ if TYPE_CHECKING:
 
 OLD_SEED_VERSION = 4        # electrum versions < 2.0
 NEW_SEED_VERSION = 11       # electrum versions >= 2.0
-FINAL_SEED_VERSION = 32     # electrum >= 2.7 will set this to prevent
+FINAL_SEED_VERSION = 33     # electrum >= 2.7 will set this to prevent
                             # old versions from overwriting new format
 
 
@@ -180,6 +180,7 @@ class WalletDB(JsonDB):
         self._convert_version_30()
         self._convert_version_31()
         self._convert_version_32()
+        self._convert_version_33()
         self.put('seed_version', FINAL_SEED_VERSION)  # just to be sure
 
         self._after_upgrade_tasks()
@@ -695,6 +696,20 @@ class WalletDB(JsonDB):
         self.data['invoices'] = invoices_new
         self.data['seed_version'] = 32
 
+    def _convert_version_33(self):
+        if not self._is_upgrade_method_needed(32, 32):
+            return
+
+        from .invoices import PR_TYPE_ONCHAIN
+        requests = self.data.get('payment_requests', {})
+        invoices = self.data.get('invoices', {})
+        for d in [invoices, requests]:
+            for key, item in list(d.items()):
+                if item['type'] == PR_TYPE_ONCHAIN:
+                    item['height'] = item.get('height') or 0
+
+        self.data['seed_version'] = 33
+
     def _convert_imported(self):
         if not self._is_upgrade_method_needed(0, 13):
             return