Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@test/functional/test_framework/test_node.py`:
- Around line 94-98: The current logic only sets has_explicit_bind by checking
extra_conf for entries starting with "bind=", causing auto-injected binds to
ignore effective settings like listen, port, and whitebind; update the code in
the block that calls append_config(datadir, extra_conf) so it computes the
effective configuration after appending and derives has_explicit_bind from that
effective config: consider any explicit "bind=" or "-bind=" entries, any
whitebind entries, whether listen=0 is set, and whether a custom port is set
(i.e., port != p2p_port(self.index)); if any of those conditions apply, treat
the node as having an explicit bind and do not inject default
p2p_port(self.index). Use the existing symbols append_config, extra_conf,
has_explicit_bind, p2p_port(self.index), listen, port, whitebind to find and
change the logic.

In `@test/functional/test_runner.py`:
- Line 490: Replace the bare assertion on results_filepath.parent.exists() with
explicit error handling: check if not results_filepath.parent.exists() and raise
a clear exception (e.g., ValueError or FileNotFoundError) or call the same
error-reporting helper used elsewhere in this module, using the same message
"Results file parent directory does not exist" so the check on
results_filepath.parent is enforced even when Python is run with -O; update the
code near the results_filepath usage (the results_filepath variable check) to
follow the existing pattern used around the other validations in this file.

---

Nitpick comments:
In `@test/functional/mempool_accept.py`:
- Around line 80-86: The inline comment "# ... 0.99 passes" is misleading
because no positive maxfeerate test follows; update the test around the
assert_raises_rpc_error call that uses check_mempool_result so the comment
matches reality: either remove the comment, replace it with a clarifying note
that positive maxfeerate values would pass without an explicit test, or add an
explicit passing assertion that calls check_mempool_result with maxfeerate=0.99
(using the same raw_tx_in_block and expected successful result_expected) to
demonstrate the positive-case; reference check_mempool_result and
raw_tx_in_block when making the change.

These findings are from an automated code review. Verify each finding against the current code and only fix it if needed.

In `test/functional/test_framework/test_node.py`:
- [SUGGESTION] lines 231-243: start() mutates the caller's extra_args list — latent shared-reference footgun
  `start()` calls `extra_args.append(...)` directly on the list reference assigned from `self.extra_args` (or the caller-supplied list). In `BitcoinTestFramework.add_nodes`, the default path is `extra_args = [[]] * num_nodes`, which produces N references to the same empty list, all of which are stored as each node's `self.extra_args`.

In the current tree this does not blow up: with the default `bind_to_localhost_only=True`, `extra_conf` contains `bind=127.0.0.1`, so `self.has_explicit_bind` is True in `__init__` and the new injection block is skipped. The five tests that set `bind_to_localhost_only=False` (feature_discover, feature_bind_extra, feature_bind_port_discover, feature_bind_port_externalip, rpc_bind) either run a single node or supply per-node `extra_args` lists that already contain `-bind=...` (so the `any(e.startswith('-bind=')...)` short-circuit kicks in). So no test currently mutates a shared list.

But any future test that sets `bind_to_localhost_only=False` while relying on the default `extra_args` would silently get every node binding to node 0's `p2p_port`/`tor_port`, producing confusing port-collision failures. Copy the list before mutating to make the new injection block defensive against the shared-default.

These findings are from an automated code review. Verify each finding against the current code and only fix it if needed.

In `test/functional/test_framework/test_node.py`:
- [SUGGESTION] test/functional/test_framework/test_node.py:231-243: start() mutates caller's extra_args list — shared-reference footgun
  Carried forward from the prior review at 314e0a3b and still valid at 086d42e6. When `extra_args` is None, `start()` aliases `self.extra_args` and appends the auto-injected `-bind=...` flags onto that referenced list. `BitcoinTestFramework.add_nodes` can install shared inner lists via `[[]] * num_nodes`, so the first node/restart can leak stale bind flags into later starts. Copy the selected list before appending, e.g. `extra_args = list(self.extra_args) if extra_args is None else list(extra_args)`.
- [NITPICK] test/functional/test_framework/test_node.py:234-238: Carry-over comment references Bitcoin regtest port 18445 and bitcoind
  Still valid at 086d42e6. The comment imported with bitcoin#22729 still mentions `bitcoind`, `bitcoin.conf`, and `127.0.0.1:18445`; the port is Bitcoin Core's regtest onion-service target, while Dash's ports differ by network and the code correctly uses `tor_port(self.index)`. Prefer Dash-neutral wording.
- [SUGGESTION] test/functional/test_framework/test_node.py:239-243: Implicit -bind injection ignores --dashd-extra-args (extra_args_from_options)
  `will_listen` and `has_explicit_bind` inspect only per-node `extra_args`, but the process is launched with `self.args + self.extra_args_from_options + extra_args`. A global `--dashd-extra-args=-listen=0` or `--dashd-extra-args=-bind=...` therefore does not suppress the auto-injected binds, which can fight user-supplied global args. Base the bind/listen decision on the same combined argument set passed to dashd.

In `test/functional/mempool_accept.py`:
- [BLOCKING] test/functional/mempool_accept.py:80-85: Missing prerequisite: bitcoin#29434
  bitcoin#29459 was added upstream immediately after the maxfeerate coverage introduced by bitcoin#29434. Upstream #29434 added the 1 BTC/kvB rejection test, the 0.99 BTC/kvB passing test, and the `src/rpc/mempool.cpp` `ParseFeeRate` path that rejects fee rates >= 1 BTC/kvB. Dash's current backport of bitcoin#29459 only adds the negative maxfeerate assertion and adapts around the missing #29434 context: the following already-known check still has no `maxfeerate=0.99`, and `src/rpc/mempool.cpp` still parses maxfeerate with `CFeeRate(AmountFromValue(...))` instead of `ParseFeeRate`. Per the review policy for full upstream backports, this missing prerequisite needs either backporting or explicit PR-description documentation as an intentional exclusion.

These findings are from an automated code review. Verify each finding against the current code and only fix it if needed.

In `test/functional/mempool_accept.py`:
- [BLOCKING] test/functional/mempool_accept.py:80-85: Missing prerequisite: bitcoin#29434 (carried forward)
  STILL VALID at bccd3ebc61. bitcoin#29459 was written upstream immediately after bitcoin#29434, which added the >=1 BTC/kvB rejection assertion, the 0.99 BTC/kvB passing assertion, and switched src/rpc/mempool.cpp maxfeerate parsing to ParseFeeRate. Current Dash still lacks that prerequisite context: test/functional/mempool_accept.py has only the negative maxfeerate assertion and the following already-known check, while src/rpc/mempool.cpp still parses maxfeerate through CFeeRate(AmountFromValue(...)) at both call sites and contains no ParseFeeRate call. The negative-feerate assertion is self-contained, but this is a full upstream backport PR and the missing prerequisite is blocking under the review policy unless the PR explicitly documents it as an intentional exclusion.

In `test/functional/test_framework/test_node.py`:
- [SUGGESTION] test/functional/test_framework/test_node.py:231-243: start() mutates caller's extra_args list — shared-reference footgun (carried forward)
  Verified still present at bccd3ebc61. When `extra_args` is None, `extra_args = self.extra_args` aliases the node's stored list, and lines 242-243 unconditionally `.append()` the auto-injected `-bind=0.0.0.0:{p2p_port(self.index)}` and `-bind=127.0.0.1:{tor_port(self.index)}=onion` flags onto that reference. Because `BitcoinTestFramework.add_nodes` constructs the default per-node extra_args as `[[]] * num_nodes`, every TestNode's `self.extra_args` default is the same list object. The first `start()` mutates the shared default; subsequent nodes / restarts see `-bind=` already present, causing `has_explicit_bind` to flip True and suppressing the correct implicit bind while carrying the wrong-index bind forward. The same hazard applies to callers passing their own list that they don't expect to be mutated. This is a latent bug introduced by this PR's bitcoin#22729 backport (the 15-line block was added by that merge). Defensively copy the list after the None-check.
- [SUGGESTION] test/functional/test_framework/test_node.py:239-243: Implicit -bind injection ignores extra_args_from_options (--dashd-extra-args) (carried forward)
  Verified still present at bccd3ebc61. `will_listen` and `has_explicit_bind` inspect only the per-node `extra_args`, but on line 258 the process is launched with `self.args + self.extra_args_from_options + extra_args`. A global `--dashd-extra-args=-listen=0` or `--dashd-extra-args=-bind=...` supplied to the test runner therefore does not influence the implicit-bind decision: the auto `-bind=` flags still get appended, which can fight a user-supplied `-listen=0` (dashd rejects `-listen=0` combined with explicit `-bind=`) or duplicate a user-supplied bind. Decide will_listen/has_explicit_bind from the same combined argument set that is actually passed to dashd. This is a latent bug introduced by this PR's bitcoin#22729 backport.

These findings are from an automated code review. Verify each finding against the current code and only fix it if needed.

In `src/init.cpp`:
- [BLOCKING] src/init.cpp:1: PR title claims bitcoin#29459 backport, but it is not in the commit stack
  The PR title is `backport: Merge bitcoin/bitcoin#30397, 22729, 29633, 29459`, but `git log upstream/develop..HEAD` at 955f92d63b shows only three merge commits: 7ea632a046 (#30397), a53fb4df0a (#22729), and 955f92d63b (#29633). The #29459 backport (negative maxfeerate assertion in test/functional/mempool_accept.py) that was present at the prior review head bccd3ebc61 has been dropped entirely from this push — `git diff 4af395d8b8..955f92d63b -- test/functional/mempool_accept.py` is empty, and mempool_accept.py is not in the PR's list of changed files. Either restore the #29459 cherry-pick (with its bitcoin#29434 prerequisite, as flagged in the prior review) or edit the PR title/description to accurately reflect the three-commit stack. Leaving the title as-is is misleading for maintainers scanning the merge queue and for anyone tracking backport coverage.

In `test/functional/test_framework/test_node.py`:
- [SUGGESTION] test/functional/test_framework/test_node.py:231-243: start() mutates caller's extra_args list — shared-reference footgun (carried forward)
  STILL VALID at 955f92d63b (verified by direct read of the file). When `start()` is called without an explicit `extra_args`, line 232 aliases `self.extra_args` (a reference, not a copy), and lines 242-243 unconditionally append the auto-injected `-bind=0.0.0.0:{p2p_port}` and `-bind=127.0.0.1:{tor_port}=onion` flags to that same list. `BitcoinTestFramework.add_nodes` builds default extra_args as `[[]] * num_nodes`, so multiple TestNode instances can share one inner list object; the first `start()` mutates the shared list, leaking stale `-bind=` flags into other nodes' first start or into the same node's next restart. On the subsequent call `has_explicit_bind` becomes True (because the previously-appended `-bind=` is still there), so the correct implicit bind for the new port is silently skipped. The same hazard applies to any caller that passes their own list and doesn't expect it to be mutated. This is a direct import of the upstream #22729 behavior, but it's worth defending against on the Dash side. Fix: copy the selected list before appending — `extra_args = list(extra_args)` after the `None` check.
- [SUGGESTION] test/functional/test_framework/test_node.py:239-243: Implicit -bind injection ignores extra_args_from_options / --dashd-extra-args (carried forward)
  STILL VALID at 955f92d63b. `will_listen` (line 239) and `has_explicit_bind` (line 240) inspect only the per-node `extra_args`, but the process is launched on line 258 with `self.args + self.extra_args_from_options + extra_args`. A user invoking `test_runner.py --dashd-extra-args='-bind=127.0.0.1:xxxx'` or `--dashd-extra-args='-listen=0'` will still get the framework's auto-injected `-bind=0.0.0.0:{p2p}` and `-bind=127.0.0.1:{tor}=onion` appended, producing conflicting/duplicate bind arguments. This is now more consequential because #22729 (also in this stack) makes InitBinds fail fast on any bind error — a spurious duplicate `-bind=` from --dashd-extra-args can now abort node startup instead of being tolerated. Compute the decision from the same combined argument set that is actually launched.