See also ERL-815.

* hasse/syntax_tools/fix_revert/OTP-15294:
  erts: Add comment about [] and nil() to The Abstract Format
  syntax_tools: Correct erl_syntax:revert/1

revert/1 did not handle the types tuple() and map() correctly.

The bug was introduced in 9ab233.

See also https://bugs.erlang.org/browse/ERL-719.

Add support of non-whole-byte binaries to `abtract/1`, `concrete/1` and
`is_literal/1`. (They are literals in the beam file)

See also ERL-413, https://bugs.erlang.org/browse/ERL-413.

This can happen when a syntactically incorrect text is passed to a
merl:qquote/2,/3 call.

The parse transform optimizes calls to some functions in merl by
converting strings into templates at compile time. If this evaluation
fails (in eval_call/4 - for example because of a sytanx error in the
parsed text) the original function call should be kept unchanged.
However in case of qquote/3 the call is converted into a combination of
quote/2 and subst/2, but upon failure the original qquote/3 call is
substituted into the wrong place. E.g.:

this expression
  merl:qquote(Pos, Text, Env)

is first converted to
  merl:subst(merl:quote(Pos, Text), Env)

then if evaluating the quote call fails into
  merl:subst(merl:qquote(Pos, Text, Env), Env)

and the expansion is run again on the internal qquote/3 argument
resulting in an infinite loop.

This is now fixed so in case of failure the original qquote/3 call is kept.

See also http://bugs.erlang.org/browse/ERL-151.