Safeguarding `pijul channel new`: it was too easy to create a new, independent root

pmeunier

Feb 27, 2023, 2:37 PM

YK7EBTF6LAPMYEHPPOUKHO3IQTA4MTKOEI77I4UWXTM4T475QKRAC

Dependencies

• [2] TDTCT6EG New channel: confusion in subcommand names
• [3] A3RM526Y Integrating identity malleability
• [4] TFK7CYFQ `pijul channel new` to create new, empty channels
• [5] PGERZ3KJ Channel renaming (also do not create a new channel when recording on a channel that doesn't exist)
• [6] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).
• [*] GHO6DWPI Refactoring iterators
• [*] L4JXJHWX pijul/*: reorganize imports and remove extern crate

Change contents

• edit in pijul/src/commands/channel.rs at line 9
  [8.987]

  [9.3080]
  + use log::debug;
• replacement in pijul/src/commands/channel.rs at line 39
  [2.26]→[4.66:92](∅→∅),[4.66]→[4.66:92](∅→∅)
  − New { name: String },
  [2.26]

  [4.187365]
  + New {

  + name: String,

  + #[clap(long = "empty")]

  + empty: bool,

  + #[clap(long = "force", short = 'f')]

  + force: bool,

  + },
• replacement in pijul/src/commands/channel.rs at line 108
  [4.107]→[4.107:155](∅→∅)
  − Some(SubCommand::New { name }) => {
  [4.107]

  [3.24716]
  + Some(SubCommand::New { name, empty, force }) => {

  + if empty && !force {

  + bail!("If creating an empty channel is really what you want, please use -f.")

  + }
• replacement in pijul/src/commands/channel.rs at line 117
  [4.425]→[4.425:477](∅→∅)
  − txn.open_or_create_channel(&name)?;
  [4.425]

  [4.477]
  + let new = txn.open_or_create_channel(&name)?;

  + if !empty {

  + // Safeguard: apply the root patch if we're creating a new channel.

  + let current = txn.current_channel()?;

  + let channel = if let Some(channel) = txn.load_channel(current)? {

  + channel

  + } else {

  + bail!("No such channel: {:?}", current)

  + };

  + let ch = channel.read();

  + use libpijul::{GraphTxnT, MutTxnTExt};

  + let h = if let Some(Ok((k, v))) =

  + libpijul::pristine::changeid_log(&txn, &ch, 0u64.into())?.next()

  + {

  + debug!("initial patch on current channel: {:?} {:?}", k, v);

  + Some(txn.get_external(&v.a)?.unwrap().into())

  + } else {

  + None

  + };

  + if let Some(h) = h {

  + let mut new = new.write();

  + txn.apply_change(&repo.changes, &mut new, &h)?;

  + }

  + }