Fixing two bugs around conflicts on the last line, where invalid patches were produced (first bug) and applied (second bug)

Dependencies

• [2] GHO6DWPI Refactoring iterators
• [3] ZRUPLBBT Colours in diff and change: separating concerns and dependencies
• [4] CCFJ7VO3 Renaming "Record" to "Hunk" in the changes
• [5] VO5OQW4W Removing anyhow in libpijul
• [6] CIEUBH46 Fixing an index-out-of-bounds error when serialising bad changes
• [*] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).
• [*] KVBLRDOU Concatenating edits with order conflict resolutions (if relevant), and parsing the text format of the result

Change contents

• edit in libpijul/src/pristine/sanakirja.rs at line 1337
  [2.45598]

  [2.45598]
  + assert!(pos > key.start);

  + assert!(pos < key.end);
• edit in libpijul/src/diff/replace.rs at line 72
  [9.45]

  [8.782161]
  + if start <= end {

  + return

  + }
• edit in libpijul/src/change/text_changes.rs at line 432
  [3.53313]→[3.53313:53356](∅→∅)
  − writeln!(w, "\\")?
• edit in libpijul/src/change/text_changes.rs at line 432
  [3.53313]

  [3.53356]
  + writeln!(w, "\n\\")?
• edit in libpijul/src/change/text_changes.rs at line 1236
  [3.85615]→[3.85615:85650](∅→∅)
  − writeln!(w, "\\")?
• edit in libpijul/src/change/text_changes.rs at line 1236
  [3.85615]

  [3.85650]
  + writeln!(w, "\n\\")?
• edit in libpijul/src/apply.rs at line 414
  [8.955847]

  [8.955847]
  + if txn.find_block_end(graph, vertex.end_pos()).is_ok()

  + || txn.find_block(graph, vertex.start_pos()).is_ok() {

  + error!("Invalid change: {:?}", vertex);

  + return Err(LocalApplyError::InvalidChange);

  + }

  +