remove some uses of $IFS

This is a step towards resolving issue #4156. It replaces uses of `$IFS`
with other solutions.

share/completions/dd.fish

@@ -3,17 +3,12 @@ complete -c dd -d 'display help and exit' -xa '--help'
 complete -c dd -d 'output version information and exit' -xa '--version'
 
 function __fish_complete_dd --description 'Complete dd operands'
-
     # set operand_string as a local variable containing the current command-line token.
     set -l operand_string (commandline -t)
 
     switch $operand_string
-
         case 'if=*' 'of=*'
-            # the read command uses $IFS to tokenise stdin input
+            string replace = ' ' -- $operand_string | read -l operand value
-            set -l IFS =
-            # $operand now contains the left side of the operator, $value the right
-            echo $operand_string | read -l operand value
 
             for entry in $value*
                 # if $entry is a directory, append a '/'
@@ -25,18 +20,9 @@ function __fish_complete_dd --description 'Complete dd operands'
             end
 
         case 'iflag=*' 'oflag=*'
-            set -l IFS =
+            string replace = ' ' -- $operand_string | read -l operand complete
-            echo $operand_string | read -l operand value
+            string match -q '*,' -- $complete
-
+            or set complete ''
-            set -l IFS ' '
-            echo $value | sed -e 's/\(.*\)\(,\)/\1 \2/' | read -l complete comma
-
-            # check if there is only one option
-            if test $comma = ''
-                set complete ''
-            else
-                set complete $complete,
-            end
 
             printf "%s\t%s\n" "$operand=$complete""append" "append mode (makes sense only for output; conv=notrunc suggested)"
             printf "%s\t%s\n" "$operand=$complete""direct" "use direct I/O for data"
@@ -51,17 +37,9 @@ function __fish_complete_dd --description 'Complete dd operands'
             printf "%s\t%s\n" "$operand=$complete""nofollow" "do not follow symbolic links"
 
         case 'conv=*'
-            set -l IFS =
+            string replace = ' ' -- $operand_string | read -l operand complete
-            echo $operand_string | read -l operand value
+            string match -q '*,' -- $complete
-
+            or set complete ''
-            set -l IFS ' '
-            echo $value | sed -e 's/\(.*\)\(,\)/\1 \2/' | read -l complete comma
-
-            if test $comma = ''
-                set complete ''
-            else
-                set complete $complete,
-            end
 
             printf "%s\t%s\n" "$operand=$complete""ascii" "from EBCDIC to ASCII"
             printf "%s\t%s\n" "$operand=$complete""ebcdic" "from ASCII to EBCDIC"

share/completions/iptables.fish

@@ -5,10 +5,7 @@ function __fish_iptables_current_table
     for token in (commandline -oc)
         switch $token
             case "--table=*"
-				set -l IFS "="
+                echo (string split -m1 = -- $token)[2]
-				echo $token | while read a b
-					echo $b
-				end
                 return 0
             case "--table"
                 set next_is_table 0
@@ -40,7 +37,8 @@ end
 
 function __fish_iptables_chains
     set -l table (__fish_iptables_current_table)
-	[ -z $table ]; and set -l table "*"
+    [ -z $table ]
+    and set -l table "*"
     set -l prerouting "PREROUTING	For packets that are coming in"
     set -l input "INPUT	For packets destined to local sockets"
     set -l output "OUTPUT	For locally-generated packets"
@@ -80,9 +78,7 @@ end
 
 function __fish_iptables_has_chain
     # Remove descriptions
-	set -l IFS "	"
+    set -l chains (__fish_iptables_chains | string split -m1 "    " | while read a b; echo $a; end)
-	set -l chains (__fish_iptables_chains | while read a b; echo $a; end)
-	set -e IFS
     set -l cmdline (commandline -op)
     for c in $chains
         if contains -- $c $cmdline

share/completions/systemctl.fish

@@ -1,9 +1,5 @@
 set -l systemd_version (systemctl --version | string match "systemd*" | string replace -r "\D*(\d+)"  '$1')
-set -l commands list-units list-sockets start stop reload restart try-restart reload-or-restart reload-or-try-restart \
+set -l commands list-units list-sockets start stop reload restart try-restart reload-or-restart reload-or-try-restart isolate kill is-active is-failed status show get-cgroup-attr set-cgroup-attr unset-cgroup-attr set-cgroup help reset-failed list-unit-files enable disable is-enabled reenable preset mask unmask link load list-jobs cancel dump list-dependencies snapshot delete daemon-reload daemon-reexec show-environment set-environment unset-environment default rescue emergency halt poweroff reboot kexec exit suspend hibernate hybrid-sleep switch-root
-	isolate kill is-active is-failed status show get-cgroup-attr set-cgroup-attr unset-cgroup-attr set-cgroup help \
-	reset-failed list-unit-files enable disable is-enabled reenable preset mask unmask link load list-jobs cancel dump \
-	list-dependencies snapshot delete daemon-reload daemon-reexec show-environment set-environment unset-environment \
-	default rescue emergency halt poweroff reboot kexec exit suspend hibernate hybrid-sleep switch-root
 if test $systemd_version -gt 208
     set commands $commands cat
     if test $systemd_version -gt 217
@@ -14,18 +10,14 @@ set -l types services sockets mounts service_paths targets automounts timers
 
 function __fish_systemd_properties
     if type -q /usr/lib/systemd/systemd
-		set IFS "="
+        /usr/lib/systemd/systemd --dump-configuration-items | string split -m1 = | while read key value
-		/usr/lib/systemd/systemd --dump-configuration-items | while read key value
+            test -n "$value"
-			if not test -z $value
+            and echo $key
-				echo $key
-			end
         end
     else if type -q /lib/systemd/systemd # Debian has not merged /lib and /usr/lib
-		set IFS "="
+        /lib/systemd/systemd --dump-configuration-items | string split -m1 = | while read key value
-		/lib/systemd/systemd --dump-configuration-items | while read key value
+            test -n "$value"
-			if not test -z $value
+            and echo $key
-				echo $key
-			end
         end
     end
 end

share/completions/vagrant.fish

@@ -7,21 +7,23 @@ end
 
 function __fish_vagrant_using_command
     set -l cmd (commandline -opc)
-  set -q cmd[2]; and test "$argv[1]" = $cmd[2]
+    set -q cmd[2]
+    and test "$argv[1]" = $cmd[2]
 end
 
 function __fish_vagrant_using_command_and_no_subcommand
     set -l cmd (commandline -opc)
-  test (count $cmd) -eq 2; and test "$argv[1]" = "$cmd[2]"
+    test (count $cmd) -eq 2
+    and test "$argv[1]" = "$cmd[2]"
 end
 
 function __fish_vagrant_using_subcommand --argument-names cmd_main cmd_sub
     set -l cmd (commandline -opc)
-    set -q cmd[3]; and test "$cmd_main" = $cmd[2] -a "$cmd_sub" = $cmd[3]
+    set -q cmd[3]
+    and test "$cmd_main" = $cmd[2] -a "$cmd_sub" = $cmd[3]
 end
 
 function __fish_vagrant_boxes --description 'Lists all available Vagrant boxes'
-  set -l IFS \n\ \t
     command vagrant box list | while read -l name _
         echo $name
     end

share/functions/__fish_complete_lpr_option.fish

@@ -2,8 +2,7 @@ function __fish_complete_lpr_option --description 'Complete lpr option'
     set -l optstr (commandline -t)
     switch $optstr
         case '*=*'
-            set -l IFS =
+            string split -m1 = -- "$optstr" | read -l opt val
-            echo $optstr | read -l opt val
             set -l descr
             for l in (lpoptions -l ^/dev/null | string match -- "*$opt*" | string replace -r '.*/(.*):\s*(.*)$' '$1 $2' | string split " ")
                 if not set -q descr[1]

share/functions/__fish_git_prompt.fish

@@ -265,8 +265,7 @@ function __fish_git_prompt_show_upstream --description "Helper function for __fi
                     # Use fetch config to fix upstream
                     set -l fetch_val (command git config "$cur_prefix".fetch)
                     if test -n "$fetch_val"
-                        set -l IFS :
+                        string split -m1 : -- "$fetch_val" | read -l trunk pattern
-                        echo "$fetch_val" | read -l trunk pattern
                         set upstream (string replace -r -- "/$trunk\$" '' $pattern) /$upstream
                     end
                 end

share/functions/__fish_print_help.fish

@@ -15,8 +15,6 @@ function __fish_print_help --description "Print help message for the specified f
         return
     end
 
-    set -l IFS \n\ \t
-
     # Render help output, save output into the variable 'help'
     set -l help
     set -l cols

share/functions/funced.fish

@@ -56,25 +56,21 @@ function funced --description 'Edit function definition'
     end
 
     if test "$editor" = fish
-        set -l IFS
         if functions -q -- $funcname
-            # Shadow IFS here to avoid array splitting in command substitution
+            functions -- $funcname | fish_indent --no-indent | read -z init
-            set init (functions -- $funcname | fish_indent --no-indent)
         end
 
         set -l prompt 'printf "%s%s%s> " (set_color green) '$funcname' (set_color normal)'
-        # Unshadow IFS since the fish_title breaks otherwise
-        set -e IFS
         if read -p $prompt -c "$init" -s cmd
-            # Shadow IFS _again_ to avoid array splitting in command substitution
+            echo -n $cmd | fish_indent | read -lz cmd
-            set -l IFS
+            eval "$cmd"
-            eval (echo -n $cmd | fish_indent)
         end
         return 0
     end
 
-    # OSX mktemp is rather restricted - no suffix, no way to automatically use TMPDIR
+    # OS X (macOS) `mktemp` is rather restricted - no suffix, no way to automatically use TMPDIR.
-    # Create a directory so we can use a ".fish" suffix for the file - makes editors pick up that it's a fish file
+    # Create a directory so we can use a ".fish" suffix for the file - makes editors pick up that
+    # it's a fish file.
     set -q TMPDIR
     or set -l TMPDIR /tmp
     set -l tmpdir (mktemp -d $TMPDIR/fish.XXXXXX)

tests/test_functions/mktemp.fish

@@ -50,8 +50,7 @@ function mktemp
     # So let's outlaw them anywhere besides the end.
     # Similarly GNU sed requires at least 3 X's, BSD sed requires none. Let's require 3.
     begin
-        set -l IFS
+        set -l chars (string split '' -- $template)
-        printf '%s' "$template" | read -la chars
         set -l found_x
         for c in $chars
             if test $c = X