'main': The optimized cmdsubst input syntax doesn't glob.

Fixes #582.

changelog.md

@@ -29,6 +29,9 @@
 - Fix `exec 2>&1;` being highlighted as an error.
   [#676]
 
+- Fix `: $(<*)` being highlighted as globbing.
+  [#582]
+
 # Changes in version 0.7.1
 
 - Remove out-of-date information from the 0.7.0 changelog.

highlighters/main/main-highlighter.zsh

@@ -498,6 +498,13 @@ _zsh_highlight_main_highlighter_highlight_list()
   else
     args=(${(z)buf})
   fi
+
+  # Special case: $(<*) isn't globbing.
+  if [[ $braces_stack == 'S' ]] && (( $+args[3] && ! $+args[4] )) && [[ $args[3] == $'\x29' ]] &&
+     [[ $args[1] == *'<'* ]] && _zsh_highlight_main__is_redirection $args[1]; then
+    highlight_glob=false
+  fi
+
   while (( $#args )); do
     arg=$args[1]
     shift args

highlighters/main/test-data/optimized-cmdsubst-input.zsh

@@ -0,0 +1,43 @@
+#!/usr/bin/env zsh
+# -------------------------------------------------------------------------------------------------
+# Copyright (c) 2018 zsh-syntax-highlighting contributors
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification, are permitted
+# provided that the following conditions are met:
+#
+#  * Redistributions of source code must retain the above copyright notice, this list of conditions
+#    and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright notice, this list of
+#    conditions and the following disclaimer in the documentation and/or other materials provided
+#    with the distribution.
+#  * Neither the name of the zsh-syntax-highlighting contributors nor the names of its contributors
+#    may be used to endorse or promote products derived from this software without specific prior
+#    written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+# FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+# IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# -------------------------------------------------------------------------------------------------
+# -*- mode: zsh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
+# vim: ft=zsh sw=2 ts=2 et
+# -------------------------------------------------------------------------------------------------
+
+# See getoutput() and getoutputfile() in zsh's C source code.
+
+BUFFER=$': $(<*)'
+
+expected_region_highlight=(
+  '1 1 builtin' # :
+  '3 7 default' # $(<*)
+  '3 7 command-substitution-unquoted' # $(<*)
+  '3 4 command-substitution-delimiter-unquoted' # $(
+  '5 5 redirection' # <
+  '6 6 default' # * - not globbing!
+  '7 7 command-substitution-delimiter-unquoted' # )
+)