v0.6.0

Changed

• Conversion is slower than in 0.5.0: md → org takes about 1.6 to 2.8
  times as long, org → md about 10 % longer. The escapes below have to
  check how org reads the output, which takes org parses of the text
  concerned; org → md guards _. lines and drops the escapes again.
  A performance check in CI now keeps it from growing unnoticed.

Fixed

Mostly found by round-tripping a real Obsidian vault, the rest by code
review and fuzzing; each of these silently changed text.

• Markup touching a word character (`x`s, foo**bar**baz) no
  longer comes back with literal markers. Org only reads markup next to
  whitespace or punctuation, so md → org now separates the two with a
  zero-width space, the org manual's escape character, and org → md
  drops it again.
• Literal text org would read as markup, such as the path /etc/ or an
  escaped \*b\*, stays literal instead of turning italic or bold,
  also when another inline node sits between the markers
  (\*b `x` c\*).
• Relative links and images ([t](notes.md#Some%20Heading)) become
  org file: links ([[file:notes.md::Some Heading][t]]) and come
  back as the same Markdown links. They used to become bare org paths,
  which org reads as a heading search rather than a file, so Emacs
  would not open them and the obsidian preset turned them into
  wikilinks. A path holding a literal %5B, %5D or :: keeps it
  instead of pointing at another file, and an org file: path holding
  # or % ([[file:C# notes.md]]) comes back pointing at that file,
  not at C.
• A heading inside a list item keeps its text as a line of the item
  and reports via onWarning, instead of silently coming back as
  literal \*\* …: org has no headline inside a list.
• A paragraph line that starts like org line syntax, such as an
  escaped 1\., \- or \#, or a lazy continuation line, stays text
  instead of turning into a list item, headline, comment or table. This
  includes a line starting with a footnote reference ([^1] text,
  which org reads as a footnote definition), one following a nested
  list or code block inside a list item, one inside bold or a link
  text spanning two lines, one ending in a bare bullet (1.), and one
  in a logseq block below its first line. The same goes for line
  syntax spanning lines (an escaped \#+begin_src … \#+end_src) or
  depending on the heading above (SCHEDULED: <…>). A paragraph that
  is exactly one of the org constructs morg writes into Markdown
  verbatim (drawers, fixed-width lines, clocks, …) still comes back as
  org.
• A line starting _. or _) converts in both directions: uniorg,
  morg's org parser, took it for a list bullet and failed on the whole
  document, or, when a list followed, silently dropped the line. Org
  reads it as text, and so does morg now.
• List item text after a nested list (- a\n - b\n\n c) stays in
  the outer item instead of moving into the nested one on the next
  round trip: org → md keeps the blank line Markdown needs there.
• A literal \[fn:1] in Markdown text stays text instead of becoming a
  footnote reference.
• Inline code holding a ~ that ends org code early (`a~ b`)
  becomes org =a~ b= instead of breaking the rest of the line. Code
  that a = would end early too stays plain text and reports via
  onWarning.
• #+OPTIONS: ^:nil is honored on org → md: a_b stays a_b
  instead of becoming a\_{b}, and the option stays.
• Bold, italic or strikethrough spanning more than two lines keeps its
  markup: org markup spans at most two lines, so its line endings
  become spaces, as Markdown renders them anyway.
• A heading inside a blockquote keeps its text as a line of the quote
  and reports via onWarning: Emacs ends a quote block at a headline.
• A fenced code block inside a list item keeps its indentation in both
  directions. md → org used to shrink the code's own indentation by up
  to the item's (if x:\n y() lost two spaces), and org → md added
  the item's indentation to every line.
• An escaped \| in a Markdown table cell becomes org's \vert{}
  entity instead of splitting the cell, and comes back as \|.
• Bare underscores and carets (my_notes_2021.md, x^y, also right
  after markup or a link: **a**_b, or in an obsidian wikilink alias:
  [[a_b.md|a_b]]) are no longer read as org sub/superscripts. md → org adds ^:{} to #+OPTIONS: when the text
  needs it; org → md honors it in a top-level #+OPTIONS: and consumes
  it where the text needs it, so an author's own options: ^:{} stays.
• Inline code spanning three or more lines converts to org; its line
  endings (LF, CRLF or CR) become spaces, which is how CommonMark
  renders them anyway.
• Inline code with whitespace at either end, as a padding typo easily
  leaves, converts to org instead of breaking the rest of the
  paragraph: org markup may not start or end with whitespace, so the
  whitespace moves just outside the code. Whitespace-only code stays
  plain text and reports via onWarning.
• An image with an anchor (![a](i.svg#part)) comes back as an image
  instead of a plain link.
• A space between text and markup inside an org table cell is kept;
  only the cell's alignment padding is trimmed.
• With the obsidian preset, an aliased wikilink in a table cell is
  written [[Page\|alias]], as Obsidian does, instead of splitting the
  cell.