cleaning up the deps and revdeps of unused changes after a channel drop

Dependencies

• [2] TZ42DX3B Properly dropping a channel
• [*] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• edit in libpijul/src/pristine/sanakirja.rs at line 1897
  [2.1183]

  [2.1183]
  + let mut unused_changes = Vec::new();

  + 'outer: for x in btree::rev_iter(&self.txn, &c, None)? {

  + let (_, p) = x?;

  + for chan in self.iter_channels("").map_err(|e| e.0)? {

  + let (name, chan) = chan.map_err(|e| e.0)?;

  + if name.as_str() == name0 {

  + continue

  + }

  + let chan = chan.read().unwrap();

  + if self.channel_has_state(&chan.states, &p.b).map_err(|e| e.0)?.is_some() {

  + break 'outer

  + }

  + if self.get_changeset(&chan.changes, &p.a).map_err(|e| e.0)?.is_some() {

  + continue 'outer

  + }

  + }

  + unused_changes.push(p.a);

  + }

  + for ch in unused_changes.iter() {

  + while btree::del(&mut self.txn, &mut self.dep, ch, None)? {}

  + while btree::del(&mut self.txn, &mut self.revdep, ch, None)? {}

  + }