'main': Don't highlight arithmetic expansions as command substitutions.

This is not perfect: we don't try to detect cases such as «$((ls); (ls))»,
which look like arithmetic expansions but are in fact command substitutions.

Fixes part of #607.

Introduces #704.

changelog.md

@@ -38,6 +38,13 @@
 - Fix `echo >&2` highlighting the `2` as a filename if a file by that name happened to exist
   [#694]
 
+- Fix `: $((42))` being highlighted as a subshell.
+  [part of #607]
+
+- Regress highlighting of `: $((ls); (ls))`: is a subshell, but will now be
+  incorrectly highlighted as an arithmetic expansion.
+  [#704]
+
 # Changes in version 0.7.1
 
 - Remove out-of-date information from the 0.7.0 changelog.

highlighters/main/main-highlighter.zsh

@@ -1222,7 +1222,8 @@ _zsh_highlight_main_highlighter_highlight_argument()
           (( i = REPLY ))
           highlights+=($reply)
           continue
-       elif [[ $arg[i+1] == $'\x28' ]]; then
+        elif [[ $arg[i+1] == $'\x28' && ${arg:$i} != $'\x28\x28'*$'\x29\x29'* ]]; then
+          # command substitution that doesn't look like an arithmetic expansion
           start=$i
           (( i += 2 ))
           _zsh_highlight_main_highlighter_highlight_list $(( start_pos + i - 1 )) S $has_end $arg[i,-1]
@@ -1237,6 +1238,10 @@ _zsh_highlight_main_highlighter_highlight_argument()
             highlights+=($(( start_pos + i - 1)) $(( start_pos + i )) command-substitution-delimiter-unquoted)
           fi
           continue
+        else
+          # TODO: if it's an arithmetic expansion, skip past it, to prevent
+          # multiplications from being highlighted as globbing (issue #607,
+          # test-data/arith1.zsh)
         fi
         while [[ $arg[i+1] == [\^=~#+] ]]; do
           (( i += 1 ))
@@ -1359,7 +1364,8 @@ _zsh_highlight_main_highlighter_highlight_double_quote()
               # $#, $*, $@, $?, $- - like $$ above
               (( k += 1 )) # highlight both dollar signs
               (( i += 1 )) # don't consider the second one as introducing another parameter expansion
-            elif [[ $arg[i+1] == $'\x28' ]]; then
+            elif [[ $arg[i+1] == $'\x28' && ${arg:$i} != $'\x28\x28'*$'\x29\x29'* ]]; then
+              # command substitution that doesn't look like an arithmetic expansion
               breaks+=( $last_break $(( start_pos + i - 1 )) )
               (( i += 2 ))
               saved_reply=($reply)

highlighters/main/test-data/arith-cmdsubst-mess.zsh

@@ -33,14 +33,14 @@ BUFFER=$': $((ls); (ls))'
 expected_region_highlight=(
   '1 1 builtin' # :
   '3 15 default' # $((ls); (ls))
-  '3 15 command-substitution-unquoted' # $((ls); (ls))
+  '3 15 command-substitution-unquoted "issue #704"' # $((ls); (ls))
-  '3 4 command-substitution-delimiter-unquoted' # $(
+  '3 4 command-substitution-delimiter-unquoted "issue #704"' # $(
-  '5 5 reserved-word' # (
+  '5 5 reserved-word "issue #704"' # (
-  '6 7 command' # ls
+  '6 7 command "issue #704"' # ls
-  '8 8 reserved-word' # )
+  '8 8 reserved-word "issue #704"' # )
-  '9 9 commandseparator' # ;
+  '9 9 commandseparator "issue #704"' # ;
-  '11 11 reserved-word' # (
+  '11 11 reserved-word "issue #704"' # (
-  '12 13 command' # ls
+  '12 13 command "issue #704"' # ls
-  '14 14 reserved-word' # )
+  '14 14 reserved-word "issue #704"' # )
-  '15 15 command-substitution-delimiter-unquoted' # )
+  '15 15 command-substitution-delimiter-unquoted "issue #704"' # )
 )

highlighters/main/test-data/arith1.zsh

@@ -0,0 +1,37 @@
+#!/usr/bin/env zsh
+# -------------------------------------------------------------------------------------------------
+# Copyright (c) 2020 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
+# -------------------------------------------------------------------------------------------------
+
+BUFFER=$': $(( 6 * 9 ))'
+
+expected_region_highlight=(
+  '1 1 builtin' # :
+  '3 14 default' # $(( 6 * 9 ))
+)
+expected_mismatch="currently the actual highlighting has one superfluous group that highlights the asterisk is highlighted as 'globbing'"

highlighters/main/test-data/arith2.zsh

@@ -0,0 +1,37 @@
+#!/usr/bin/env zsh
+# -------------------------------------------------------------------------------------------------
+# Copyright (c) 2020 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
+# -------------------------------------------------------------------------------------------------
+
+BUFFER=$': "$(( 6 * 9 ))"'
+
+expected_region_highlight=(
+  '1 1 builtin' # :
+  '3 16 default' # "$(( 6 * 9 ))"
+  '3 16 double-quoted-argument' # "$(( 6 * 9 ))"
+)