Note when we're allowed to unwrap channel parameters in docs

This further documents the parameter-fetching utilities in
`InMemorySigner` to hopefully make them more robust against future
spurious `unwrap`s.

diff --git a/lightning/src/sign/mod.rs b/lightning/src/sign/mod.rs
index ebcd106b80b4a2ac55e8358701e56747afeaa8a2..5a5ac4968021f7bc5161e665db41d8c0b00e9091 100644 (file)
--- a/lightning/src/sign/mod.rs
+++ b/lightning/src/sign/mod.rs
@@ -894,6 +894,7 @@ impl InMemorySigner {
        /// Returns the counterparty's pubkeys.
        ///
        /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+       /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
        pub fn counterparty_pubkeys(&self) -> Option<&ChannelPublicKeys> {
                self.get_channel_parameters()
                        .and_then(|params| params.counterparty_parameters.as_ref().map(|params| &params.pubkeys))
@@ -904,6 +905,7 @@ impl InMemorySigner {
        /// broadcast a transaction.
        ///
        /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+       /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
        pub fn counterparty_selected_contest_delay(&self) -> Option<u16> {
                self.get_channel_parameters()
                        .and_then(|params| params.counterparty_parameters.as_ref().map(|params| params.selected_contest_delay))
@@ -914,6 +916,7 @@ impl InMemorySigner {
        /// if they broadcast a transaction.
        ///
        /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+       /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
        pub fn holder_selected_contest_delay(&self) -> Option<u16> {
                self.get_channel_parameters().map(|params| params.holder_selected_contest_delay)
        }
@@ -921,6 +924,7 @@ impl InMemorySigner {
        /// Returns whether the holder is the initiator.
        ///
        /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+       /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
        pub fn is_outbound(&self) -> Option<bool> {
                self.get_channel_parameters().map(|params| params.is_outbound_from_holder)
        }
@@ -928,6 +932,7 @@ impl InMemorySigner {
        /// Funding outpoint
        ///
        /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+       /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
        pub fn funding_outpoint(&self) -> Option<&OutPoint> {
                self.get_channel_parameters().map(|params| params.funding_outpoint.as_ref()).flatten()
        }
@@ -936,6 +941,7 @@ impl InMemorySigner {
        /// building transactions.
        ///
        /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+       /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
        pub fn get_channel_parameters(&self) -> Option<&ChannelTransactionParameters> {
                self.channel_parameters.as_ref()
        }
@@ -944,6 +950,7 @@ impl InMemorySigner {
        /// determining a channel's category, i. e. legacy/anchors/taproot/etc.
        ///
        /// Will return `None` if [`ChannelSigner::provide_channel_parameters`] has not been called.
+       /// In general, this is safe to `unwrap` only in [`ChannelSigner`] implementation.
        pub fn channel_type_features(&self) -> Option<&ChannelTypeFeatures> {
                self.get_channel_parameters().map(|params| &params.channel_type_features)
        }