Assignments to positional parameters using scalar assignment syntax is
a feature: it is covered by upstream's test suite ("append to positional
parameter" in Test/A06assign.ztst).

Merge remote-tracking branch 'upstream/pr/326'

* upstream/pr/326:
  'main': Internal cleanup: drop $style_override.

Conflicts:
	highlighters/main/main-highlighter.zsh (context lines only)

This commit is based on the work done by
Jorge Israel Peña (blaenk) in #136.

Changes:
* Adjusted to changes on the latest master branch.
* Use regular path highlighter colors by default.
* Break out early if the separator color is the same to
  improve performance.
* Tests.

Changes the interface of _zsh_highlight_main_highlighter_check_path().

Suggested-by: m0viefreak

If possible, try to use the zsh/parameter module to get
information about a shell words.

This avoids subshells and is a huge speed improvement
on systems such as cygwin.

Note 1:
$commands does not know about PATH_DIRS. So in case
PATH_DIRS is set, 'type -w' is still used if nothing
else matches.

Note 2:
zsh/parameter can't distinguish between 'command' and
'hashed'. Adjusted the test for that case to XFAIL.

The ideal solution would be if whence had an option to
put the result in REPLY instead of printing it to stdout.

Closes #291.

* commit '2f18ba':
  'main': use zsh/parameter to resolve alias
  driver: load zsh/parameter if available

If possible, use zsh/parameter to avoid forks.

Fixes #263.

* upstream/pr/308:
  'main': Fix issue #302, "Process substitution misparsed as redirection".
  'main': Factor out common code.  No functional change.
  'main': Add a regression test for issue #302, "Process substitution misparsed as redirection".

Follow-up to 2176692704.

Part of #306.

Found-by: m0viefreak
(in #298)

* upstream/pr/315:
  'main': optimization that in my tests shows 2.7s -> 2.2s

Consider indexing long buffers (say 300 chars). E.g. following line:
      integer offset=${${buf[start_pos+1,len]}[(i)$needle]}
will gradually go into large indices for first index [a,] and be kept
at large index for second index [,b]. Instead, we can remove already
processed characters from buf:
    proc_buf="${proc_buf[offset + $#arg + 1,-1]}"
$offset and $#arg are small, first index will not be large. $proc_buf
will be smaller and smaller and the second index [,-1] will run shorter
and shorter.

Keep references in prose as '~/.zshrc': using $ZDOTDIR in that context would
be confusing, and people who set $ZDOTDIR understand these references.

This also removes an implicit assumption that ~/.zshrc is idempotent.

Inspired by #312.

Use correct indexing also for cursor-matchingbracket.

Fixup for 95d82568d8

Part of #306

ISEARCH_ACTIVE was renamed ISEARCHMATCH_ACTIVE in workers/38921
(commit f06be0ffcf2c to zsh itself).

Fixes #299.

Closes #297.

Use 'print -r --' instead, so literal backslashes in $BUFFER aren't expanded.

Found-by: Matthew Martin

The new output improves readability of the 'main' highlighter's test output.

Without this when bracket_color_size is 0,
    $(( (levelpos[$pos] - 1) % bracket_color_size + 1 ))
errors with division by zero.

Since the _zsh_highlight_add_highlight that the tests use ignores
ZSH_HIGHLIGHT_STYLES, we can test both an injective mapping and an empty
mapping at once.

Closes #287. Testing the keys directly removes the need for
unused_highlight which will be removed next.

This removes the need for the typepos array.