fix(will): prevent double invalidation when postponing a signed will

When postponing the delivery time of an already signed/sent will, the user
was asked to sign the on-chain invalidation transaction twice before the new
(postponed) will could be built.

Root cause: after the invalidation tx was broadcast, on_success_invalidate
restarted task_phase1 to rebuild the will, but the old will items were still
marked COMPLETE/PUSHED with their original tx.locktime (the on-chain
invalidation did not update the in-memory status). The postpone check therefore
fired WillPostponedException a second time, requesting another invalidation.

Fix:
- Add Will.mark_invalidated_by_tx(will, tx): marks INVALIDATED every valid will
  item that spends a prevout consumed by the just-broadcast invalidation tx.
  Setting INVALIDATED clears the VALID flag, removing those items from
  only_valid_list so the postpone/expire check no longer fires.
- Call it from loop_broadcast_invalidating after a successful broadcast (txid
  obtained) and persist via save_willitems. On the phase-1 restart the old will
  is no longer VALID, so the will is rebuilt directly: a single invalidation
  signature followed by the new will.

Tests: add test_will_mark_invalidated_by_tx and
test_will_mark_invalidated_by_tx_no_match plus the WillPostponedException
hierarchy assertion. 184 tests pass; smoke and external-zip OK; ruff clean.

Bump version to 0.3.1.

bal/VERSION

@@ -1 +1 @@
-0.3.0
+0.3.1

bal/__init__.py

@@ -34,4 +34,4 @@ The plugin targets Electrum 4.7.2 (the last stable release exposing
 ``json_db.register_dict``) and PyQt6.
 """
 
-__version__ = "0.3.0"
+__version__ = "0.3.1"

bal/core/plugin_base.py

@@ -91,7 +91,7 @@ class BalPlugin(BasePlugin):
     """
 
     _version = None
-    __version__ = "0.3.0"  # AUTOMATICALLY GENERATED DO NOT EDIT
+    __version__ = "0.3.1"  # AUTOMATICALLY GENERATED DO NOT EDIT
 
     # Command used to open an .ics calendar file, per operating system.
     default_app = {

bal/core/will.py

@@ -420,6 +420,31 @@ class Will:
             _logger.debug("len utxo_to_spend <=0")
             pass
 
+    @staticmethod
+    def mark_invalidated_by_tx(will, tx):
+        """Mark as INVALIDATED every valid will item that spends at least one
+        of the prevouts consumed by ``tx`` (the on-chain invalidation tx that
+        was just broadcast).
+
+        Once the invalidation tx is broadcast, the previously signed/sent will
+        transactions that relied on those same UTXOs can no longer be mined, so
+        their will items must stop being VALID.  Setting INVALIDATED clears the
+        VALID flag (see WillItem.set_status), which removes them from
+        only_valid_list and therefore prevents the postpone/expire check from
+        firing a *second* invalidation on the next pass.
+
+        Returns the list of will ids that were marked.
+        """
+        spent_prevouts = {i.prevout.to_str() for i in tx.inputs()}
+        invalidated = []
+        for wid in Will.only_valid_list(will):
+            w = will[wid]
+            wi_prevouts = {i.prevout.to_str() for i in w.tx.inputs()}
+            if spent_prevouts & wi_prevouts:
+                Will.set_invalidate(wid, will)
+                invalidated.append(wid)
+        return invalidated
+
     @staticmethod
     def is_new(will):
         for wid, w in will.items():

bal/gui/qt/dialogs.py

@@ -708,6 +708,19 @@ class BalBuildWillDialog(BalDialog):
             self.msg_set_invalidating(self.msg_ok())
             if not txid:
                 _logger.debug(f"should not be none txid: {txid}")
+            else:
+                # The invalidation tx is now broadcast, so the old signed/sent
+                # will transactions spending those same UTXOs can no longer be
+                # mined.  Mark them INVALIDATED (which clears their VALID flag)
+                # so the postpone/expire check does NOT fire a second
+                # invalidation when phase 1 is restarted to rebuild the new
+                # (postponed) will.
+                invalidated = Will.mark_invalidated_by_tx(
+                    self.bal_window.willitems, tx
+                )
+                if invalidated:
+                    _logger.debug(f"invalidated will items: {invalidated}")
+                    self.bal_window.save_willitems()
 
         except TxBroadcastError as e:
             _logger.error(f"fail to broadcast transaction:{e}")

bal/manifest.json

@@ -1,7 +1,7 @@
 {
     "name": "bal",
     "fullname": "Bitcoin After Life",
-    "version": "0.3.0",
+    "version": "0.3.1",
     "description": "Provides free and decentralized Bitcoin inheritance support. Build time-locked 'will' transactions that transfer funds to your heirs if you stop refreshing them (dead-man's switch), optionally relayed by will-executor servers.",
     "author": "Svatantrya",
     "licence": "MIT",