Use curly underlines for errors in default themes

Given that this curly underline will also be red, it should be widely understood as error. Since fish always renders immediately (and synchronously), typing "echo" will briefly show an intermediate curly line. Maybe fish should redraw after a timer elapses? This is probably unrelated to this patch. As mentioned in cc9849c279 (Curly underlines in set_color and fish_color_*, 2025-04-13), there are still some terminals that interpret "\e[4:3m" as something other than curly underline. Some of them interpret it as background/foreground color, and some terminal multiplexers downgrade it to straight underlines (which often happens due to a false positive). I want to change this in multiplexers where possible (see https://github.com/orgs/tmux/discussions/4477) but for now, disable this feature in multiplexers (there are just a handful). In a few years, those terminals will maybe agree with XTerm. Until then, use XTGETTCAP as a temporary stepping stone. We could also read the terminfo database but that will give only very few true positives, and lots of false negatives. Better implement XTGETTCAP in the relevant terminals. Note that if the universal variables use the "--track" flag (from the grandparent commit), then rm -rf /tmp/newhome foot -e env $HOME=/tmp/newhome fish xterm -e env $HOME=/tmp/newhome fish will "magically work". For foot, $fish_color_error will have --underline=curly. For xterm, it will not, due to the call to "fish_config theme update". But of course since it's a universal variable, running fish in xterm would also downgrade the fish running in other terminals. Add a "fish_config theme save --yes" flag because "status xtgettcap" requires stdin to be a terminal. I'd probably drop this requirement, and make "status xtgettcap" always use fish's stdin and not its own. That'd be cheating because an external command can't do that but I don't think this change would be hurting anyone.
Builtin for querying terminal capabilities/name/version
2026-04-19 14:51:13 -03:00 · 2025-04-29 13:59:27 +02:00 · 2025-04-29 13:59:27 +02:00 · 2025-04-29 13:59:27 +02:00
55 changed files with 720 additions and 225 deletions
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -69,7 +69,12 @@ Improved terminal support
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 - Support for curly underlines in `fish_color_*` variables and :doc:`set_color <cmds/set_color>` (:issue:`10957`).
 - Underlines can now be colored independent of text (:issue:`7619`).
+- Errors are now highlighted with curly underlines in the default themes.
+  For compatibility with terminals that interpret the curly-underline escape sequence in an unexpected way,
+  the default themes enable this only if the terminal advertises support for the ``Su`` capability via XTGETTCAP.
 - New documentation page `Terminal Compatibility <terminal-compatibility.html>`_ (also accessible via ``man fish-terminal-compatibility``) lists required and optional terminal control sequences used by fish.
+- :doc:`status <cmds/status>` learned the ``xtgettcap`` subcommand, to query terminfo capabilities via XTGETTCAP commands.
+- :doc:`status <cmds/status>` learned the ``xtversion`` subcommand, to show the terminal's name and version (as reported by via the XTVERSION command).

 Other improvements
 ------------------
--- a/doc_src/cmds/fish_config.rst
+++ b/doc_src/cmds/fish_config.rst
@@ -10,7 +10,7 @@ Synopsis

    fish_config [browse]
    fish_config prompt (choose | list | save | show)
-    fish_config theme (choose | demo | dump | list | save | show)
+    fish_config theme (choose | demo | dump | list | save | show | update)

 Description
 -----------
@@ -40,6 +40,9 @@ Available subcommands for the ``theme`` command:
 - ``list`` lists the names of the available sample themes.
 - ``save`` saves the given theme to :ref:`universal variables <variables-universal>`.
 - ``show`` shows what the given sample theme (or all) would look like.
+- ``update`` updates any ``fish_color_*`` and ``fish_pager_color_*`` variables whose value contains
+             "--track=THEME". They are set to the latest version of that theme, and the tracking
+             option is preserved. Note that ``fish_config theme update`` is run at fish startup.

 The **-h** or **--help** option displays help about using this command.

--- a/doc_src/cmds/set_color.rst
+++ b/doc_src/cmds/set_color.rst
@@ -59,6 +59,12 @@ The following options are available:
 **-u** or **--underline**, or **-uSTYLE** or **--underline=STYLE**
    Set the underline mode; supported styles are **single** (default) and **curly**.

+**--track=THEME**
+    Ignored. Included by default in universally-scoped color variables to tell fish to update
+    them as the associated theme changes.
+    This flag can be set for all variables when loading a theme with the `--track`` option, that is
+    :doc:`fish_config theme save THEME --track <fish_config>`.
+
 **-h** or **--help**
    Displays help about using this command.

--- a/doc_src/cmds/status.rst
+++ b/doc_src/cmds/status.rst
@@ -33,6 +33,8 @@ Synopsis
    status buildinfo
    status get-file FILE
    status list-files [PATH]
+    status xtgettcap TERMINFO-CAPABILITY
+    status xtversion

 Description
 -----------
@@ -117,6 +119,13 @@ The following operations (subcommands) are available:
    This lists the files embedded in the fish binary at compile time. Only files where the path starts with the optional *FILE* argument are shown.
    Returns 0 if something was printed, 1 otherwise.

+**xtgettcap** *TERMINFO-CAPABILITY*
+    Query the terminal for a terminfo capability via XTGETTCAP.
+    Returns 0 if the capability is present and 1 otherwise.
+
+**xtversion**
+    Show the terminal name and version (XTVERSION).
+
 Notes
 -----

--- a/doc_src/terminal-compatibility.rst
+++ b/doc_src/terminal-compatibility.rst
@@ -177,7 +177,9 @@ Optional Commands
     - Su
     - Reset underline color to the default (follow the foreground color).
     - kitty
-   * - ``\e[ Ps S``
+   * - .. _indn:
+
+       ``\e[ Ps S``
     - indn
     - Scroll forward Ps lines.
     -
@@ -269,6 +271,12 @@ Optional Commands
     - FinalTerm
   * - ``\eP+q Pt \e\\``
     -
-     - Request terminfo capability (XTGETTCAP). The parameter is the capability's hex-encoded terminfo code.
-       Specifically, fish asks for the ``indn`` string capability. At the time of writing string capabilities are supported by kitty and foot.
-     - XTerm, kitty, foot
+     - Request terminfo capability (XTGETTCAP).
+       The parameter is the capability's hex-encoded terminfo code.
+       To advertise a capability, the response must of the form
+       ``\eP1+q Pt \e\\`` or ``\eP1+q Pt = Pt \e\\``.
+       In either variant the first parameter must be the hex-encoded terminfo code.
+       In the second variant, fish ignores the part after the equals sign.
+
+       At startup, fish checks for the presence of the `indn <#indn>`_ string capability.
+     - XTerm, kitty, foot, wezterm, contour
--- a/0
+++ b/0
--- a/share/completions/fish_config.fish
+++ b/share/completions/fish_config.fish
@@ -1,6 +1,6 @@
 complete fish_config -f
 set -l prompt_commands choose save show list
-set -l theme_commands choose demo dump save show list
+set -l theme_commands choose demo dump save show list update
 complete fish_config -n __fish_use_subcommand -a prompt -d 'View and pick from the sample prompts'
 complete fish_config -n "__fish_seen_subcommand_from prompt; and not __fish_seen_subcommand_from $prompt_commands" \
    -a choose -d 'View and pick from the sample prompts'
@@ -16,6 +16,7 @@ complete fish_config -n __fish_use_subcommand -a browse -d 'Open the web-based U

 complete fish_config -n __fish_use_subcommand -a theme -d 'View and pick from the sample themes'
 complete fish_config -n '__fish_seen_subcommand_from theme; and __fish_seen_subcommand_from choose save show' -a '(fish_config theme list)'
+complete fish_config -n '__fish_seen_subcommand_from theme; and __fish_seen_subcommand_from save' -l track -d 'Add --track to color variables to apply future theme updates'
 complete fish_config -n "__fish_seen_subcommand_from theme; and not __fish_seen_subcommand_from $theme_commands" \
    -a choose -d 'View and pick from the sample themes'
 complete fish_config -n "__fish_seen_subcommand_from theme; and not __fish_seen_subcommand_from $theme_commands" \
@@ -28,3 +29,5 @@ complete fish_config -n "__fish_seen_subcommand_from theme; and not __fish_seen_
    -a demo -d 'Show example in the current theme'
 complete fish_config -n "__fish_seen_subcommand_from theme; and not __fish_seen_subcommand_from $theme_commands" \
    -a dump -d 'Print the current theme in .theme format'
+complete fish_config -n "__fish_seen_subcommand_from theme; and not __fish_seen_subcommand_from $theme_commands" \
+    -a update -d "Update universal colors that have the tracking flag set"
--- a/share/completions/set_color.fish
+++ b/share/completions/set_color.fish
@@ -8,3 +8,4 @@ complete -c set_color -s r -l reverse -d 'Reverse color text'
 complete -c set_color -s u -l underline -d 'Underline style' -a 'single curly'
 complete -c set_color -s h -l help -d 'Display help and exit'
 complete -c set_color -s c -l print-colors -d 'Print a list of all accepted color names'
+complete -c set_color -l track -xa '(fish_config theme list)' -d 'Ignored. Used in color variables to follow theme changes'
--- a/share/completions/status.fish
+++ b/share/completions/status.fish
@@ -27,7 +27,9 @@ set -l __fish_status_all_commands \
    list-files \
    print-stack-trace \
    stack-trace \
-    test-feature
+    test-feature \
+    xtgettcap \
+    xtversion

 # These are the recognized flags.
 complete -c status -s h -l help -d "Display help and exit"
@@ -64,6 +66,8 @@ complete -f -c status -n "not __fish_seen_subcommand_from $__fish_status_all_com
 complete -f -c status -n "not __fish_seen_subcommand_from $__fish_status_all_commands" -a get-file -d "Print an embedded file from the fish binary"
 complete -f -c status -n "not __fish_seen_subcommand_from $__fish_status_all_commands" -a list-files -d "List embedded files contained in the fish binary"
 complete -f -c status -n "not __fish_seen_subcommand_from $__fish_status_all_commands" -a fish-path -d "Print the path to the current instance of fish"
+complete -f -c status -n "not __fish_seen_subcommand_from $__fish_status_all_commands" -a xtgettcap -d "Query the terminal for a terminfo capability"
+complete -f -c status -n "not __fish_seen_subcommand_from $__fish_status_all_commands" -a xtversion -d "Show terminal name and version"

 # The job-control command changes fish state.
 complete -f -c status -n "not __fish_seen_subcommand_from $__fish_status_all_commands" -a job-control -d "Set which jobs are under job control"
--- a/share/functions/__fish_config_interactive.fish
+++ b/share/functions/__fish_config_interactive.fish
@@ -30,12 +30,13 @@ if status is-interactive
    # Commands to run in interactive sessions can go here
 end" >$__fish_config_dir/config.fish

-        echo yes | fish_config theme save "fish default"
+        fish_config theme save "fish default" --yes --track
        set -Ue fish_color_keyword fish_color_option
    end
    if test $__fish_initialized -lt 3800 && test "$fish_color_search_match[1]" = bryellow
        set --universal fish_color_search_match[1] white
    end
+    fish_config theme update

    #
    # Generate man page completions if not present.
--- a/share/functions/__fish_in_gnu_screen.fish
+++ b/share/functions/__fish_in_gnu_screen.fish
@@ -0,0 +1,3 @@
+function __fish_in_gnu_screen
+    test -n "$STY" || contains -- $TERM screen screen-256color
+end
--- a/share/functions/__fish_in_terminal_multiplexer.fish
+++ b/share/functions/__fish_in_terminal_multiplexer.fish
@@ -0,0 +1,9 @@
+function __fish_in_terminal_multiplexer
+    set -l terminal_name "(status xtversion | string match -r '^\S*')"
+    string match -q -- tmux $terminal_name ||
+        __fish_in_gnu_screen ||
+        # Emacs does probably not support multiplexing between multiple parent
+        # terminals, but it is affected by the same issues.  Same for Vim's
+        # :terminal TODO detect that before they implement XTGETTCAP.
+        contains -- $TERM dvtm-256color eterm eterm-color
+end
--- a/share/functions/__fish_shared_key_bindings.fish
+++ b/share/functions/__fish_shared_key_bindings.fish
@@ -77,7 +77,11 @@ function __fish_shared_key_bindings -d "Bindings shared between emacs and vi mod
    bind --preset $argv alt-l __fish_list_current_token
    bind --preset $argv alt-o __fish_preview_current_file
    bind --preset $argv alt-w __fish_whatis_current_token
-    bind --preset $argv ctrl-l scrollback-push clear-screen
+    bind --preset $argv ctrl-l (
+        if not __fish_in_gnu_screen && and __fish_xtgettcap indn
+            echo scrollback-push
+        end
+    ) clear-screen
    bind --preset $argv ctrl-c clear-commandline
    bind --preset $argv ctrl-u backward-kill-line
    bind --preset $argv ctrl-k kill-line
--- a/share/functions/__fish_xtgettcap.fish
+++ b/share/functions/__fish_xtgettcap.fish
@@ -0,0 +1,12 @@
+function __fish_xtgettcap --argument-names terminfo_code
+    if test $FISH_UNIT_TESTS_RUNNING = 1
+        return 1
+    end
+    set -l varname __fish_tcap_$terminfo_code
+    if not set -q $varname\[0\]
+        set --global $varname (
+            status xtgettcap $terminfo_code && echo true || echo false
+        )
+    end
+    test "$$varname" = true
+end
--- a/share/functions/fish_config.fish
+++ b/share/functions/fish_config.fish
@@ -1,5 +1,11 @@
-function fish_config --description "Launch fish's web based configuration"
-    argparse h/help -- $argv
+# Variables a theme is allowed to set
+set -l theme_var_filter '^fish_(?:pager_)?color.*$'
+
+function fish_config --description "Launch fish's web based configuration" \
+    --inherit-variable theme_var_filter
+
+    set -l _flag_track
+    argparse h/help track yes -- $argv
    or return

    if set -q _flag_help
@@ -10,6 +16,15 @@ function fish_config --description "Launch fish's web based configuration"
    set -l cmd $argv[1]
    set -e argv[1]

+    if set -q _flag_track[1] && not { test "$cmd" = theme && test "$argv[1]" = save }
+        echo >&2 fish_config: --track: unknown option
+        return 1
+    end
+    if set -q _flag_yes[1] && not { contains "$cmd" prompt theme && test "$argv[1]" = save }
+        echo >&2 fish_config: --yes: unknown option
+        return 1
+    end
+
    set -q cmd[1]
    or set cmd browse

@@ -65,9 +80,6 @@ function fish_config --description "Launch fish's web based configuration"
        return 1
    end

-    # Variables a theme is allowed to set
-    set -l theme_var_filter '^fish_(?:pager_)?color.*$'
-
    switch $cmd
        case prompt
            # prompt - for prompt switching
@@ -144,8 +156,8 @@ function fish_config --description "Launch fish's web based configuration"
                        functions --erase fish_right_prompt
                    end
                case save
-                    read -P"Overwrite prompt? [y/N]" -l yesno
-                    if string match -riq 'y(es)?' -- $yesno
+                    if set -q _flag_yes[1] ||
+                            { read -P"Overwrite prompt? [y/N]" -l yesno; string match -riq 'y(es)?' -- $yesno }
                        echo Overwriting
                        # Skip the cp if unnecessary,
                        # or we'd throw an error on a stock fish.
@@ -274,8 +286,10 @@ function fish_config --description "Launch fish's web based configuration"
                    set -l have_colors

                    if contains -- $cmd save
-                        read -P"Overwrite your current theme? [y/N] " -l yesno
-                        if not string match -riq 'y(es)?' -- $yesno
+                        if not set -q _flag_yes &&
+                                { read -P"Overwrite your current theme? [y/N] " -l yesno
+                                    not string match -riq 'y(es)?' -- $yesno
+                                }
                            echo Not overwriting >&2
                            return 1
                        end
@@ -292,34 +306,7 @@ function fish_config --description "Launch fish's web based configuration"
                    # If we are choosing a theme or saving from a named theme, load the theme now.
                    # Otherwise, we'll persist the currently loaded/themed variables (in case of `theme save`).
                    if set -q argv[1]
-                        set -l files $dirs/$argv[1].theme
-                        set -l file
-
-                        for f in $files
-                            if test -e "$f"
-                                set file $f
-                                break
-                            end
-                        end
-
-                        if not set -q file[1]
-                            if status list-files tools/web_config/themes/$argv[1].theme &>/dev/null
-                                set file tools/web_config/themes/$argv[1].theme
-                            else
-                                echo "No such theme: $argv[1]" >&2
-                                echo "Searched directories: $dirs" >&2
-                                return 1
-                            end
-                        end
-
-                        set -l content
-                        if string match -qr '^tools/' -- $file
-                            set content (status get-file $file)
-                        else
-                            read -z content < $file
-                        end
-
-                        printf %s\n $content | while read -lat toks
+                        __fish_config_theme_get $argv[1] | while read -lat toks
                            # The whitelist allows only color variables.
                            # Not the specific list, but something named *like* a color variable.
                            # This also takes care of empty lines and comment lines.
@@ -331,7 +318,7 @@ function fish_config --description "Launch fish's web based configuration"
                            if test x"$scope" = x-U; and set -qg $toks[1]
                                set -eg $toks[1]
                            end
-                            set $scope $toks
+                            set $scope $toks $_flag_track=$argv[1]
                            set -a have_colors $toks[1]
                        end

@@ -343,7 +330,7 @@ function fish_config --description "Launch fish's web based configuration"
                            # Erase conflicting global variables so we don't get a warning and
                            # so changes are observed immediately.
                            set -eg $c
-                            set $scope $c
+                            set $scope $c $_flag_track=$argv[1]
                        end
                    else
                        # We're persisting whatever current colors are loaded (maybe in the global scope)
@@ -365,6 +352,8 @@ function fish_config --description "Launch fish's web based configuration"
                    # If we've made it this far, we've either found a theme file or persisted the current
                    # state (if any). In all cases we haven't failed, so return 0.
                    return 0
+                case update
+                    __fish_config_theme_update $argv
                case dump
                    # Write the current theme in .theme format, to stdout.
                    set -L | string match -r $theme_var_filter
@@ -374,3 +363,100 @@ function fish_config --description "Launch fish's web based configuration"
            end
    end
 end
+
+function __fish_config_theme_get
+    set -l dirs $__fish_config_dir/themes $__fish_data_dir/tools/web_config/themes
+    set -l files $dirs/$argv[1].theme
+    set -l file
+    set -l is_default_theme false
+
+    for f in $files
+        if test -e "$f"
+            set file $f
+            if test $f = $__fish_data_dir/tools/web_config/themes/$argv[1].theme
+                set is_default_theme true
+            end
+            break
+        end
+    end
+
+    if not set -q file[1]
+        if status list-files tools/web_config/themes/$argv[1].theme &>/dev/null
+            set file tools/web_config/themes/$argv[1].theme
+            set is_default_theme true
+        else
+            echo "No such theme: $argv[1]" >&2
+            echo "Searched directories: $dirs" >&2
+            return 1
+        end
+    end
+
+    set -l content (
+        if string match -qr '^tools/' -- $file
+            status get-file $file
+        else
+            string join \n <$file
+        end
+    )
+    if $is_default_theme && not __fish_in_gnu_screen && not __fish_xtgettcap Su && not __fish_in_terminal_multiplexer
+        set content (string replace -- --underline=curly "" $content)
+    end
+
+    string join \n $content
+end
+
+function __fish_config_show_tracked_color_vars
+    set -l color_var $argv[1]
+    set -l _flag_track
+    argparse --ignore-unknown track= -- _set_color $argv[2..]
+    or return $status
+    if not set -q _flag_track[1]
+        return
+    end
+    if set -q _flag_track[2]
+        echo >&2 "fish_config: $color_var: --track option can only be specified once"
+        exit 1
+    end
+    if test (printf %s $_flag_track | count) -ne 0
+        echo >&2 "fish_config: $color_var: error: tracking theme name must not contain newlines"
+        exit 1
+    end
+    printf %s\n $color_var $_flag_track
+end
+
+function __fish_config_theme_update --inherit-variable theme_var_filter
+    if set -q argv[1]
+        echo "fish_config: too many arguments" >&2
+        return 1
+    end
+    set -l themes
+
+    set -l tracking_variables (
+            set --universal --long |
+            string match -r '^fish_(?:pager_)?color.*$' |
+            string replace -r '.*' '__fish_config_show_tracked_color_vars $0' |
+            source
+    )
+    or return $status
+    string join \n $tracking_variables |
+        while read --line _colorvar theme
+            if not contains -- $theme $themes
+                set -a themes $theme
+            end
+        end
+
+    for theme in $themes
+        set -l colorvars
+        string join \n $tracking_variables |
+            while read --line color_var t
+                if test $t = $theme
+                    set -a colorvars $color_var
+                end
+            end
+        set -l theme_escaped (string escape -- $theme)
+        __fish_config_theme_get $theme |
+            string match -r -- "^(?:$(string join '|' $colorvars))\b .*" |
+            string replace -r '.*' "set -U \$0 --track=$theme_escaped" |
+            source
+    end
+end
--- a/share/tools/web_config/themes/Base16
+++ b/share/tools/web_config/themes/Base16
@@ -10,7 +10,7 @@ fish_color_comment f7ca88
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end ba8baf
-fish_color_error ab4642
+fish_color_error ab4642 --underline=curly
 fish_color_escape 86c1b9
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Base16
+++ b/share/tools/web_config/themes/Base16
@@ -10,7 +10,7 @@ fish_color_comment f7ca88
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end ba8baf
-fish_color_error ab4642
+fish_color_error ab4642 --underline=curly
 fish_color_escape 86c1b9
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Base16
+++ b/share/tools/web_config/themes/Base16
@@ -10,7 +10,7 @@ fish_color_comment ffcc66
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end cc99cc
-fish_color_error f2777a
+fish_color_error f2777a --underline=curly
 fish_color_escape 66cccc
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Bay
+++ b/share/tools/web_config/themes/Bay
@@ -9,7 +9,7 @@ fish_color_comment FF9640
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end FFB273
-fish_color_error FF7400
+fish_color_error FF7400 --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Dracula.theme
+++ b/share/tools/web_config/themes/Dracula.theme
@@ -21,7 +21,7 @@ fish_color_comment 6272a4
 fish_color_cwd 50fa7b
 fish_color_cwd_root red
 fish_color_end ffb86c
-fish_color_error ff5555
+fish_color_error ff5555 --underline=curly
 fish_color_escape ff79c6
 fish_color_history_current --bold
 fish_color_host bd93f9
--- a/share/tools/web_config/themes/Fairground.theme
+++ b/share/tools/web_config/themes/Fairground.theme
@@ -9,7 +9,7 @@ fish_color_comment FFE100
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end 8D003B
-fish_color_error EC3B86
+fish_color_error EC3B86 --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Just
+++ b/share/tools/web_config/themes/Just
@@ -9,7 +9,7 @@ fish_color_comment B0B0B0
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end 969696
-fish_color_error FFA779
+fish_color_error FFA779 --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Lava.theme
+++ b/share/tools/web_config/themes/Lava.theme
@@ -6,7 +6,7 @@ fish_color_command FF9400
 fish_color_quote BF9C30
 fish_color_redirection BF5B30
 fish_color_end FF4C00
-fish_color_error FFDD73
+fish_color_error FFDD73 --underline=curly
 fish_color_param FFC000
 fish_color_comment A63100
 fish_color_selection white --background=brblack --bold
--- a/share/tools/web_config/themes/Mono
+++ b/share/tools/web_config/themes/Mono
@@ -9,7 +9,7 @@ fish_color_comment 4e4e4e
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end 767676
-fish_color_error b2b2b2
+fish_color_error b2b2b2 --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Mono
+++ b/share/tools/web_config/themes/Mono
@@ -6,7 +6,7 @@ fish_color_command ffffff
 fish_color_quote a8a8a8
 fish_color_redirection 808080
 fish_color_end 949494
-fish_color_error 585858
+fish_color_error 585858 --underline=curly
 fish_color_param d7d7d7
 fish_color_comment bcbcbc
 fish_color_selection white --background=brblack --bold
--- a/share/tools/web_config/themes/None.theme
+++ b/share/tools/web_config/themes/None.theme
@@ -9,7 +9,7 @@ fish_color_comment
 fish_color_cwd normal
 fish_color_cwd_root normal
 fish_color_end
-fish_color_error
+fish_color_error --underline=curly
 fish_color_escape
 fish_color_history_current
 fish_color_host normal
--- a/share/tools/web_config/themes/Nord.theme
+++ b/share/tools/web_config/themes/Nord.theme
@@ -11,7 +11,7 @@ fish_color_comment 4c566a --italics
 fish_color_cwd 5e81ac
 fish_color_cwd_root bf616a
 fish_color_end 81a1c1
-fish_color_error bf616a
+fish_color_error bf616a --underline=curly
 fish_color_escape ebcb8b
 fish_color_history_current e5e9f0 --bold
 fish_color_host a3be8c
--- a/share/tools/web_config/themes/Old
+++ b/share/tools/web_config/themes/Old
@@ -9,7 +9,7 @@ fish_color_comment 30BE30
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end FF7B7B
-fish_color_error A40000
+fish_color_error A40000 --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Seaweed.theme
+++ b/share/tools/web_config/themes/Seaweed.theme
@@ -9,7 +9,7 @@ fish_color_comment 5C9900
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end 8EEB00
-fish_color_error 60B9CE
+fish_color_error 60B9CE --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Snow
+++ b/share/tools/web_config/themes/Snow
@@ -6,7 +6,7 @@ fish_color_command 164CC9
 fish_color_quote 4C3499
 fish_color_redirection 248E8E
 fish_color_end 02BDBD
-fish_color_error 9177E5
+fish_color_error 9177E5 --underline=curly
 fish_color_param 4319CC
 fish_color_comment 007B7B
 fish_color_selection white --background=brblack --bold
--- a/share/tools/web_config/themes/Solarized
+++ b/share/tools/web_config/themes/Solarized
@@ -10,7 +10,7 @@ fish_color_comment 586e75
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end 268bd2
-fish_color_error dc322f
+fish_color_error dc322f --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Solarized
+++ b/share/tools/web_config/themes/Solarized
@@ -7,7 +7,7 @@ fish_color_command 586e75
 fish_color_quote 839496
 fish_color_redirection 6c71c4
 fish_color_end 268bd2
-fish_color_error dc322f
+fish_color_error dc322f --underline=curly
 fish_color_param 657b83
 fish_color_comment 93a1a1
 fish_color_selection white --background=brblack --bold
--- a/share/tools/web_config/themes/Tomorrow
+++ b/share/tools/web_config/themes/Tomorrow
@@ -10,7 +10,7 @@ fish_color_comment e7c547
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end c397d8
-fish_color_error d54e53
+fish_color_error d54e53 --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/Tomorrow
+++ b/share/tools/web_config/themes/Tomorrow
@@ -7,7 +7,7 @@ fish_color_command b294bb
 fish_color_quote b5bd68
 fish_color_redirection 8abeb7
 fish_color_end b294bb
-fish_color_error cc6666
+fish_color_error cc6666 --underline=curly
 fish_color_param 81a2be
 fish_color_comment f0c674
 fish_color_selection white --background=brblack --bold
--- a/share/tools/web_config/themes/Tomorrow.theme
+++ b/share/tools/web_config/themes/Tomorrow.theme
@@ -10,7 +10,7 @@ fish_color_comment eab700
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end 8959a8
-fish_color_error c82829
+fish_color_error c82829 --underline=curly
 fish_color_escape 00a6b2
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/ayu
+++ b/share/tools/web_config/themes/ayu
@@ -7,7 +7,7 @@ fish_color_command 39BAE6
 fish_color_quote C2D94C
 fish_color_redirection FFEE99
 fish_color_end F29668
-fish_color_error FF3333
+fish_color_error FF3333 --underline=curly
 fish_color_param B3B1AD
 fish_color_comment 626A73
 fish_color_selection --background=E6B450 --bold
--- a/share/tools/web_config/themes/ayu
+++ b/share/tools/web_config/themes/ayu
@@ -10,7 +10,7 @@ fish_color_comment ABB0B6
 fish_color_cwd 399EE6
 fish_color_cwd_root red
 fish_color_end ED9366
-fish_color_error F51818
+fish_color_error F51818 --underline=curly
 fish_color_escape 4CBF99
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/ayu
+++ b/share/tools/web_config/themes/ayu
@@ -10,7 +10,7 @@ fish_color_comment 5C6773
 fish_color_cwd 73D0FF
 fish_color_cwd_root red
 fish_color_end F29E74
-fish_color_error FF3333
+fish_color_error FF3333 --underline=curly
 fish_color_escape 95E6CB
 fish_color_history_current --bold
 fish_color_host normal
--- a/share/tools/web_config/themes/coolbeans.theme
+++ b/share/tools/web_config/themes/coolbeans.theme
@@ -9,7 +9,7 @@ fish_color_comment '888'  '--italics'
 fish_color_cwd 0A0
 fish_color_cwd_root A00
 fish_color_end 009900
-fish_color_error F22
+fish_color_error F22 --underline=curly
 fish_color_escape 0AA
 fish_color_history_current 0AA
 fish_color_host normal
--- a/share/tools/web_config/themes/fish
+++ b/share/tools/web_config/themes/fish
@@ -11,7 +11,7 @@ fish_color_comment red
 fish_color_cwd green
 fish_color_cwd_root red
 fish_color_end green
-fish_color_error brred
+fish_color_error brred --underline=curly
 fish_color_escape brcyan
 fish_color_history_current --bold
 fish_color_host normal
--- a/src/builtins/fish_key_reader.rs
+++ b/src/builtins/fish_key_reader.rs
@@ -153,7 +153,7 @@ fn setup_and_process_keys(
    unsafe { libc::tcsetattr(0, TCSANOW, &*shell_modes()) };
    terminal_protocol_hacks();
    let blocking_query: OnceCell<RefCell<Option<TerminalQuery>>> = OnceCell::new();
-    initial_query(&blocking_query, streams.out, None);
+    initial_query(&blocking_query, streams.out);

    if continuous_mode {
        streams.err.append(L!("\n"));
--- a/src/builtins/read.rs
+++ b/src/builtins/read.rs
@@ -28,6 +28,7 @@
 use crate::wutil::encoding::zero_mbstate;
 use crate::wutil::perror;
 use libc::SEEK_CUR;
+use std::num::NonZeroUsize;
 use std::os::fd::RawFd;
 use std::sync::atomic::Ordering;

@@ -219,12 +220,14 @@ fn read_interactive(
    conf.complete_ok = shell;
    conf.highlight_ok = shell;
    conf.syntax_check_ok = shell;
+    conf.prompt_ok = true;

    // No autosuggestions or abbreviations in builtin_read.
    conf.autosuggest_ok = false;
    conf.expand_abbrev_ok = false;

    conf.exit_on_interrupt = true;
+    conf.in_builtin_read = true;
    conf.in_silent_mode = silent;

    conf.left_prompt_cmd = prompt.to_owned();
@@ -244,7 +247,7 @@ fn read_interactive(

    let mline = {
        let _interactive = parser.push_scope(|s| s.is_interactive = true);
-        reader_readline(parser, nchars)
+        reader_readline(parser, NonZeroUsize::try_from(nchars).ok())
    };
    terminal_protocols_disable_ifn();
    if let Some(line) = mline {
--- a/src/builtins/set_color.rs
+++ b/src/builtins/set_color.rs
@@ -86,6 +86,13 @@ pub fn set_color(parser: &Parser, streams: &mut IoStreams, argv: &mut [&wstr]) -
                // In future we change both to actually print an error.
                return Err(STATUS_INVALID_ARGS);
            }
+            Err(MultipleTracking) => {
+                streams.err.append(wgettext_fmt!(
+                    "%ls: --track option can only be specified once\n",
+                    argv[0]
+                ));
+                return Err(STATUS_INVALID_ARGS);
+            }
            Err(UnknownColor(arg)) => {
                streams
                    .err
@@ -124,7 +131,7 @@ pub fn set_color(parser: &Parser, streams: &mut IoStreams, argv: &mut [&wstr]) -
        specified_face.fg.unwrap_or(Color::None),
        specified_face.bg.unwrap_or(Color::None),
        specified_face.underline_color.unwrap_or(Color::None),
-        specified_face.style,
+        specified_face.style.unwrap_or_default(),
    ));

    if specified_face.fg.is_some() && outp.contents().is_empty() {
--- a/src/builtins/status.rs
+++ b/src/builtins/status.rs
@@ -1,5 +1,3 @@
-use std::os::unix::prelude::*;
-
 use super::prelude::*;
 use crate::common::{get_executable_path, str2wcstring, PROGRAM_NAME};
 use crate::future_feature_flags::{self as features, feature_test};
@@ -11,6 +9,9 @@
 use libc::F_OK;
 use nix::errno::Errno;
 use nix::NixPath;
+use std::os::unix::ffi::OsStrExt;
+
+mod query;

 macro_rules! str_enum {
    ($name:ident, $(($val:ident, $str:expr)),* $(,)?) => {
@@ -37,7 +38,7 @@ fn to_wstr(self) -> &'static wstr {

 use StatusCmd::*;
 #[derive(Clone, Copy)]
-enum StatusCmd {
+pub(in crate::builtins::status) enum StatusCmd {
    STATUS_CURRENT_CMD = 1,
    STATUS_BASENAME,
    STATUS_DIRNAME,
@@ -62,6 +63,8 @@ enum StatusCmd {
    STATUS_BUILDINFO,
    STATUS_GET_FILE,
    STATUS_LIST_FILES,
+    STATUS_XTGETTCAP,
+    STATUS_XTVERSION,
 }

 str_enum!(
@@ -96,6 +99,8 @@ enum StatusCmd {
    (STATUS_STACK_TRACE, "print-stack-trace"),
    (STATUS_STACK_TRACE, "stack-trace"),
    (STATUS_TEST_FEATURE, "test-feature"),
+    (STATUS_XTGETTCAP, "xtgettcap"),
+    (STATUS_XTVERSION, "xtversion"),
 );

 /// Values that may be returned from the test-feature option to status.
@@ -527,6 +532,12 @@ pub fn status(parser: &Parser, streams: &mut IoStreams, args: &mut [&wstr]) -> B
                return Err(STATUS_CMD_ERROR);
            }
        }
+        STATUS_XTGETTCAP => {
+            return query::status_xtgettcap(parser, streams, cmd, args);
+        }
+        STATUS_XTVERSION => {
+            return query::status_xtversion(parser, streams, cmd, args);
+        }
        ref s => {
            if !args.is_empty() {
                streams.err.append(wgettext_fmt!(
@@ -714,7 +725,9 @@ pub fn status(parser: &Parser, streams: &mut IoStreams, args: &mut [&wstr]) -> B
                | STATUS_FEATURES
                | STATUS_TEST_FEATURE
                | STATUS_GET_FILE
-                | STATUS_LIST_FILES => {
+                | STATUS_LIST_FILES
+                | STATUS_XTGETTCAP
+                | STATUS_XTVERSION => {
                    unreachable!("")
                }
            }
--- a/src/builtins/status/query.rs
+++ b/src/builtins/status/query.rs
@@ -0,0 +1,166 @@
+use std::ops::ControlFlow;
+use std::rc::Rc;
+
+use crate::builtins::prelude::*;
+
+use crate::common::wcs2string;
+use crate::global_safety::RelaxedAtomicBool;
+use crate::input_common::{
+    terminal_protocols_disable_ifn, InputEventQueuer, TerminalQuery, XtgettcapQuery,
+};
+use crate::nix::isatty;
+use crate::reader::{
+    query_xtgettcap, querying_allowed, reader_pop, reader_push, reader_readline, ReaderConfig,
+    UserQuery,
+};
+use crate::terminal::TerminalCommand::QueryPrimaryDeviceAttribute;
+use crate::terminal::{Output, Outputter, XTVERSION};
+use libc::STDOUT_FILENO;
+
+use super::StatusCmd;
+
+pub(crate) fn status_xtversion(
+    parser: &Parser,
+    streams: &mut IoStreams,
+    cmd: &wstr,
+    args: &[&wstr],
+) -> BuiltinResult {
+    use super::StatusCmd::STATUS_XTVERSION;
+    if !args.is_empty() {
+        streams.err.append(wgettext_fmt!(
+            BUILTIN_ERR_ARG_COUNT2,
+            cmd,
+            STATUS_XTVERSION.to_wstr(),
+            0,
+            args.len()
+        ));
+        return Err(STATUS_INVALID_ARGS);
+    }
+
+    let run_query = { move |_query: &mut Option<TerminalQuery>| ControlFlow::Break(()) };
+    synchronous_query(parser, streams, cmd, &STATUS_XTVERSION, Box::new(run_query))?;
+
+    let Some(xtversion) = XTVERSION.get() else {
+        return Err(STATUS_CMD_ERROR);
+    };
+
+    streams.out.appendln(xtversion);
+
+    Ok(SUCCESS)
+}
+
+pub(crate) fn status_xtgettcap(
+    parser: &Parser,
+    streams: &mut IoStreams,
+    cmd: &wstr,
+    args: &[&wstr],
+) -> BuiltinResult {
+    use super::StatusCmd::STATUS_XTGETTCAP;
+    if !querying_allowed() {
+        return Err(STATUS_CMD_ERROR);
+    }
+    if args.len() != 1 {
+        streams.err.append(wgettext_fmt!(
+            BUILTIN_ERR_ARG_COUNT2,
+            cmd,
+            STATUS_XTGETTCAP.to_wstr(),
+            1,
+            args.len()
+        ));
+        return Err(STATUS_INVALID_ARGS);
+    }
+    let result = Rc::new(RelaxedAtomicBool::new(false));
+    let run_query = {
+        let terminfo_code = wcs2string(args[0]);
+        let result = Rc::clone(&result);
+        move |query: &mut Option<TerminalQuery>| {
+            assert!(matches!(
+                *query,
+                None | Some(TerminalQuery::PrimaryDeviceAttribute(None))
+            ));
+            let mut output = Outputter::stdoutput().borrow_mut();
+            output.begin_buffering();
+            query_xtgettcap(output.by_ref(), &terminfo_code);
+            output.write_command(QueryPrimaryDeviceAttribute);
+            output.end_buffering();
+            *query = Some(TerminalQuery::PrimaryDeviceAttribute(Some(
+                XtgettcapQuery {
+                    terminfo_code,
+                    result,
+                },
+            )));
+            ControlFlow::Continue(())
+        }
+    };
+    synchronous_query(parser, streams, cmd, &STATUS_XTGETTCAP, Box::new(run_query))?;
+    if !result.load() {
+        return Err(STATUS_CMD_ERROR);
+    }
+    Ok(SUCCESS)
+}
+
+fn synchronous_query(
+    parser: &Parser,
+    streams: &mut IoStreams,
+    cmd: &wstr,
+    subcmd: &StatusCmd,
+    run_query: UserQuery,
+) -> Result<(), ErrorCode> {
+    if !isatty(streams.stdin_fd) {
+        streams.err.append(wgettext_fmt!(
+            "%s %s: stdin is not a TTY",
+            cmd,
+            subcmd.to_wstr(),
+        ));
+        return Err(STATUS_INVALID_ARGS);
+    };
+    let out_fd = STDOUT_FILENO;
+    if !isatty(out_fd) {
+        streams.err.append(wgettext_fmt!(
+            "%s %s: stdout is not a TTY",
+            cmd,
+            subcmd.to_wstr(),
+        ));
+        return Err(STATUS_INVALID_ARGS);
+    };
+
+    if let Some(query_state) = parser.blocking_query.get() {
+        if (run_query)(&mut query_state.borrow_mut()).is_break() {
+            return Ok(());
+        }
+    } else {
+        // We are the first reader.
+        let empty_spot = parser.pending_user_query.replace(Some(run_query));
+        assert!(empty_spot.is_none());
+    }
+
+    let mut conf = ReaderConfig::default();
+    conf.inputfd = streams.stdin_fd;
+    conf.prompt_ok = false;
+    conf.exit_on_interrupt = true;
+
+    let pending_keys = {
+        let mut reader = reader_push(parser, L!(""), conf);
+        {
+            let _interactive = parser.push_scope(|s| s.is_interactive = true);
+            let no_line = reader_readline(parser, None);
+            assert!(no_line.is_none());
+        }
+        terminal_protocols_disable_ifn();
+        let input_data = reader.get_input_data_mut();
+        let pending_keys = std::mem::take(&mut input_data.queue);
+        // We blocked code and mapping execution so input function args must be empty.
+        assert!(input_data.input_function_args.is_empty());
+        if input_data.paste_buffer.is_some() {
+            FLOG!(
+                reader,
+                "Bracketed paste was interrupted; dropping uncommitted paste buffer"
+            )
+        }
+        reader_pop();
+        pending_keys
+    };
+    FLOGF!(reader, "Adding %lu pending keys", pending_keys.len());
+    parser.pending_keys.borrow_mut().extend(pending_keys);
+    Ok(())
+}
--- a/src/highlight/highlight.rs
+++ b/src/highlight/highlight.rs
@@ -28,7 +28,7 @@
 };
 use crate::path::{path_as_implicit_cd, path_get_cdpath, path_get_path, paths_are_same_file};
 use crate::terminal::Outputter;
-use crate::text_face::{parse_text_face, TextFace, UnderlineStyle};
+use crate::text_face::{parse_text_face, SpecifiedTextFace, TextFace, UnderlineStyle};
 use crate::threads::assert_is_background_thread;
 use crate::tokenizer::{variable_assignment_equals_pos, PipeOrRedir};
 use crate::wchar::{wstr, WString, L};
@@ -140,12 +140,16 @@ pub(crate) fn resolve_spec_uncached(
        vars: &dyn Environment,
    ) -> TextFace {
        let resolve_role = |role| {
-            vars.get_unless_empty(get_highlight_var_name(role))
-                .or_else(|| vars.get_unless_empty(get_highlight_var_name(get_fallback(role))))
-                .or_else(|| vars.get_unless_empty(get_highlight_var_name(HighlightRole::normal)))
-                .as_ref()
-                .map(parse_text_face_for_highlight)
-                .unwrap_or_else(TextFace::default)
+            for role in [role, get_fallback(role), HighlightRole::normal] {
+                if let Some(face) = vars
+                    .get_unless_empty(get_highlight_var_name(role))
+                    .as_ref()
+                    .and_then(parse_text_face_for_highlight)
+                {
+                    return face;
+                }
+            }
+            TextFace::default()
        };
        let mut face = resolve_role(highlight.foreground);

@@ -162,7 +166,8 @@ pub(crate) fn resolve_spec_uncached(
        if highlight.valid_path {
            if let Some(valid_path_var) = vars.get(L!("fish_color_valid_path")) {
                // Historical behavior is to not apply background.
-                let valid_path_face = parse_text_face_for_highlight(&valid_path_var);
+                let valid_path_face =
+                    parse_text_face_for_highlight(&valid_path_var).unwrap_or_default();
                // Apply the foreground, except if it's normal. The intention here is likely
                // to only override foreground if the valid path color has an explicit foreground.
                if !valid_path_face.fg.is_normal() {
@@ -181,19 +186,21 @@ pub(crate) fn resolve_spec_uncached(
 }

 /// Return the internal color code representing the specified color.
-pub(crate) fn parse_text_face_for_highlight(var: &EnvVar) -> TextFace {
+pub(crate) fn parse_text_face_for_highlight(var: &EnvVar) -> Option<TextFace> {
    let face = parse_text_face(var.as_list());
-    let default = TextFace::default();
-    let fg = face.fg.unwrap_or(default.fg);
-    let bg = face.bg.unwrap_or(default.bg);
-    let underline_color = face.underline_color.unwrap_or(default.underline_color);
-    let style = face.style;
-    TextFace {
-        fg,
-        bg,
-        underline_color,
-        style,
-    }
+    (face != SpecifiedTextFace::default()).then(|| {
+        let default = TextFace::default();
+        let fg = face.fg.unwrap_or(default.fg);
+        let bg = face.bg.unwrap_or(default.bg);
+        let underline_color = face.underline_color.unwrap_or(default.underline_color);
+        let style = face.style.unwrap_or_default();
+        TextFace {
+            fg,
+            bg,
+            underline_color,
+            style,
+        }
+    })
 }

 fn command_is_valid(
--- a/src/input_common.rs
+++ b/src/input_common.rs
@@ -18,10 +18,7 @@
    KittyKeyboardProgressiveEnhancementsDisable, KittyKeyboardProgressiveEnhancementsEnable,
    ModifyOtherKeysDisable, ModifyOtherKeysEnable,
 };
-use crate::terminal::{
-    Capability, Output, Outputter, KITTY_KEYBOARD_SUPPORTED, SCROLL_FORWARD_SUPPORTED,
-    SCROLL_FORWARD_TERMINFO_CODE,
-};
+use crate::terminal::{Capability, Output, Outputter, KITTY_KEYBOARD_SUPPORTED, XTVERSION};
 use crate::threads::{iothread_port, is_main_thread};
 use crate::universal_notifier::default_notifier;
 use crate::wchar::{encode_byte_to_char, prelude::*};
@@ -32,6 +29,7 @@
 use std::os::fd::RawFd;
 use std::os::unix::ffi::OsStrExt;
 use std::ptr;
+use std::rc::Rc;
 use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
 use std::time::Duration;

@@ -327,6 +325,8 @@ pub struct KeyInputEvent {
 pub enum ImplicitEvent {
    /// end-of-file was reached.
    Eof,
+    /// Done
+    Break,
    /// An event was handled internally, or an interrupt was received. Check to see if the reader
    /// loop should exit.
    CheckExit,
@@ -758,15 +758,21 @@ pub fn function_set_status(&mut self, status: bool) {
    }
 }

-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Debug, Eq, PartialEq)]
 pub enum CursorPositionQuery {
    MouseLeft(ViewportPosition),
    ScrollbackPush,
 }

-#[derive(Eq, PartialEq)]
+#[derive(Debug)]
+pub struct XtgettcapQuery {
+    pub terminfo_code: Vec<u8>,
+    pub result: Rc<RelaxedAtomicBool>,
+}
+
+#[derive(Debug)]
 pub enum TerminalQuery {
-    PrimaryDeviceAttribute,
+    PrimaryDeviceAttribute(Option<XtgettcapQuery>),
    CursorPositionReport(CursorPositionQuery),
 }

@@ -932,6 +938,8 @@ fn try_readch(&mut self, blocking: bool) -> Option<CharEvent> {
                            );
                            let ok = stop_query(self.blocking_query());
                            assert!(ok);
+                            // TODO only if cancellation
+                            self.push_front(CharEvent::Implicit(ImplicitEvent::Break));
                        }
                        continue;
                    }
@@ -959,10 +967,7 @@ fn parse_escape_sequence(
        assert!(buffer.len() <= 2);
        let recursive_invocation = buffer.len() == 2;
        let Some(next) = self.try_readb(buffer) else {
-            if !self.paste_is_buffering() {
-                return Some(KeyEvent::from_raw(key::Escape));
-            }
-            return None;
+            return Some(KeyEvent::from_raw(key::Escape));
        };
        let invalid = KeyEvent::from_raw(key::Invalid);
        if recursive_invocation && next == b'\x1b' {
@@ -1223,6 +1228,7 @@ fn parse_csi(&mut self, buffer: &mut Vec<u8>) -> Option<KeyEvent> {
                _ => return None,
            },
            b'c' if private_mode == Some(b'?') => {
+                FLOG!(reader, "Received primary device attribute response");
                self.push_front(CharEvent::QueryResponse(
                    QueryResponseEvent::PrimaryDeviceAttribute,
                ));
@@ -1369,13 +1375,12 @@ fn parse_xtversion(&mut self, buffer: &mut Vec<u8>) -> Option<()> {
        if buffer.get(3)? != &b'|' {
            return None;
        }
+        let xtversion = str2wcstring(&buffer[4..buffer.len()]);
        FLOG!(
            reader,
-            format!(
-                "Received XTVERSION response: {}",
-                str2wcstring(&buffer[4..buffer.len()])
-            )
+            format!("Received XTVERSION response: {}", xtversion)
        );
+        XTVERSION.get_or_init(|| xtversion);
        None
    }

@@ -1432,9 +1437,17 @@ fn parse_dcs(&mut self, buffer: &mut Vec<u8>) -> Option<KeyEvent> {
                format!("Received XTGETTCAP response: {}", str2wcstring(&key))
            );
        }
-        if key == SCROLL_FORWARD_TERMINFO_CODE.as_bytes() {
-            SCROLL_FORWARD_SUPPORTED.store(true);
-            FLOG!(reader, "Scroll forward is supported");
+        if let Some(TerminalQuery::PrimaryDeviceAttribute(Some(tcap_query))) =
+            &*self.blocking_query()
+        {
+            if tcap_query.terminfo_code == key {
+                if tcap_query.result.swap(true) {
+                    FLOG!(
+                        reader,
+                        "Error: received multiple XTGETTCAP responses for user query"
+                    );
+                }
+            }
        }
        return None;
    }
--- a/src/io.rs
+++ b/src/io.rs
@@ -772,6 +772,10 @@ pub fn new(fd: RawFd) -> Self {
        }
    }

+    pub fn as_raw_fd(&self) -> RawFd {
+        self.fd
+    }
+
    fn append(&mut self, s: &wstr) -> bool {
        if self.errored {
            return false;
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -14,7 +14,7 @@
 };
 use crate::fds::{open_dir, BEST_O_SEARCH};
 use crate::global_safety::RelaxedAtomicBool;
-use crate::input_common::{terminal_protocols_disable_ifn, TerminalQuery};
+use crate::input_common::{terminal_protocols_disable_ifn, CharEvent, TerminalQuery};
 use crate::io::IoChain;
 use crate::job_group::MaybeJobId;
 use crate::operation_context::{OperationContext, EXPANSION_LIMIT_DEFAULT};
@@ -25,6 +25,7 @@
 use crate::parse_execution::{EndExecutionReason, ExecutionContext};
 use crate::parse_tree::{parse_source, LineCounter, ParsedSourceRef};
 use crate::proc::{job_reap, JobGroupRef, JobList, JobRef, Pid, ProcStatus};
+use crate::reader::UserQuery;
 use crate::signal::{signal_check_cancel, signal_clear_cancel, Signal};
 use crate::threads::assert_is_main_thread;
 use crate::util::get_time;
@@ -37,6 +38,7 @@
 #[cfg(not(target_has_atomic = "64"))]
 use portable_atomic::AtomicU64;
 use std::cell::{Ref, RefCell, RefMut};
+use std::collections::VecDeque;
 use std::ffi::{CStr, OsStr};
 use std::fs::File;
 use std::io::Write;
@@ -442,6 +444,10 @@ pub struct Parser {
    pub global_event_blocks: AtomicU64,

    pub blocking_query: OnceCell<RefCell<Option<TerminalQuery>>>,
+
+    pub pending_user_query: RefCell<Option<UserQuery>>,
+
+    pub pending_keys: RefCell<VecDeque<CharEvent>>,
 }

 impl Parser {
@@ -460,6 +466,8 @@ pub fn new(variables: Rc<EnvStack>, cancel_behavior: CancelBehavior) -> Parser {
            profile_items: RefCell::default(),
            global_event_blocks: AtomicU64::new(0),
            blocking_query: OnceCell::new(),
+            pending_user_query: RefCell::new(None),
+            pending_keys: RefCell::new(VecDeque::new()),
        };

        match open_dir(CStr::from_bytes_with_nul(b".\0").unwrap(), BEST_O_SEARCH) {
--- a/src/reader.rs
+++ b/src/reader.rs
@@ -85,6 +85,7 @@
 use crate::input_common::terminal_protocols_disable_ifn;
 use crate::input_common::CursorPositionQuery;
 use crate::input_common::ImplicitEvent;
+use crate::input_common::InputEventQueuer;
 use crate::input_common::QueryResponseEvent;
 use crate::input_common::TerminalQuery;
 use crate::input_common::IN_DVTM;
@@ -134,9 +135,7 @@
    QueryCursorPosition, QueryKittyKeyboardProgressiveEnhancements, QueryPrimaryDeviceAttribute,
    QueryXtgettcap, QueryXtversion,
 };
-use crate::terminal::{
-    Capability, KITTY_KEYBOARD_SUPPORTED, SCROLL_FORWARD_SUPPORTED, SCROLL_FORWARD_TERMINFO_CODE,
-};
+use crate::terminal::{Capability, KITTY_KEYBOARD_SUPPORTED};
 use crate::termsize::{termsize_invalidate_tty, termsize_last, termsize_update};
 use crate::text_face::parse_text_face;
 use crate::text_face::TextFace;
@@ -238,25 +237,25 @@ fn redirect_tty_after_sighup() {
 pub(crate) fn initial_query(
    blocking_query: &OnceCell<RefCell<Option<TerminalQuery>>>,
    out: &mut impl Output,
-    vars: Option<&dyn Environment>,
 ) {
    blocking_query.get_or_init(|| {
-        let query = if is_dumb() || IN_MIDNIGHT_COMMANDER.load() || IN_DVTM.load() {
-            None
-        } else {
+        let query = querying_allowed().then(|| {
            // Query for kitty keyboard protocol support.
            out.write_command(QueryKittyKeyboardProgressiveEnhancements);
            out.write_command(QueryXtversion);
-            if let Some(vars) = vars {
-                query_capabilities_via_dcs(out.by_ref(), vars);
-            }
            out.write_command(QueryPrimaryDeviceAttribute);
-            Some(TerminalQuery::PrimaryDeviceAttribute)
-        };
+            TerminalQuery::PrimaryDeviceAttribute(None)
+        });
        RefCell::new(query)
    });
 }

+pub(crate) type UserQuery = Box<dyn FnOnce(&mut Option<TerminalQuery>) -> ControlFlow<()>>;
+
+pub(crate) fn querying_allowed() -> bool {
+    !(is_dumb() || IN_MIDNIGHT_COMMANDER.load() || IN_DVTM.load())
+}
+
 /// The stack of current interactive reading contexts.
 fn reader_data_stack() -> &'static mut Vec<Pin<Box<ReaderData>>> {
    struct ReaderDataStack(UnsafeCell<Vec<Pin<Box<ReaderData>>>>);
@@ -273,7 +272,7 @@ pub fn reader_in_interactive_read() -> bool {
    reader_data_stack()
        .iter()
        .rev()
-        .any(|reader| reader.conf.exit_on_interrupt)
+        .any(|reader| reader.conf.in_builtin_read)
 }

 /// Access the top level reader data.
@@ -338,6 +337,9 @@ pub struct ReaderConfig {
    /// Whether to allow autosuggestions.
    pub autosuggest_ok: bool,

+    /// Whether to show a prompt.
+    pub prompt_ok: bool,
+
    /// Whether to reexecute prompt function before final rendering.
    pub transient_prompt: bool,

@@ -347,6 +349,9 @@ pub struct ReaderConfig {
    /// Whether to exit on interrupt (^C).
    pub exit_on_interrupt: bool,

+    /// Whether we are in builtin read.
+    pub in_builtin_read: bool,
+
    /// If set, do not show what is typed.
    pub in_silent_mode: bool,

@@ -691,6 +696,7 @@ fn read_i(parser: &Parser) {
    conf.syntax_check_ok = true;
    conf.expand_abbrev_ok = true;
    conf.autosuggest_ok = check_bool_var(parser.vars(), L!("fish_autosuggestion_enabled"), true);
+    conf.prompt_ok = true;
    conf.transient_prompt = check_bool_var(parser.vars(), L!("fish_transient_prompt"), false);

    if parser.is_breakpoint() && function::exists(DEBUG_PROMPT_FUNCTION_NAME, parser) {
@@ -882,6 +888,8 @@ pub fn reader_init(will_restore_foreground_pgroup: bool) {
            term_donate(/*quiet=*/ true);
        }
    }
+
+    terminal_protocol_hacks();
 }

 pub fn reader_deinit(in_signal_handler: bool, restore_foreground_pgroup: bool) {
@@ -1061,8 +1069,7 @@ pub fn reader_reading_interrupted(data: &mut ReaderData) -> i32 {
 /// characters even if a full line has not yet been read. Note: the returned value may be longer
 /// than nchars if a single keypress resulted in multiple characters being inserted into the
 /// commandline.
-pub fn reader_readline(parser: &Parser, nchars: usize) -> Option<WString> {
-    let nchars = NonZeroUsize::try_from(nchars).ok();
+pub fn reader_readline(parser: &Parser, nchars: Option<NonZeroUsize>) -> Option<WString> {
    let data = current_data().unwrap();
    let mut reader = Reader { parser, data };
    reader.readline(nchars)
@@ -2202,73 +2209,77 @@ fn readline(&mut self, nchars: Option<NonZeroUsize>) -> Option<WString> {
        initial_query(
            &self.parser.blocking_query,
            &mut BufferedOutputter::new(Outputter::stdoutput()),
-            Some(self.parser.vars()),
        );

-        // HACK: Don't abandon line for the first prompt, because
-        // if we're started with the terminal it might not have settled,
-        // so the width is quite likely to be in flight.
-        //
-        // This means that `printf %s foo; fish` will overwrite the `foo`,
-        // but that's a smaller problem than having the omitted newline char
-        // appear constantly.
-        //
-        // I can't see a good way around this.
-        if !self.first_prompt {
-            self.screen
-                .reset_abandoning_line(usize::try_from(termsize_last().width).unwrap());
+        if self.conf.prompt_ok {
+            // HACK: Don't abandon line for the first prompt, because
+            // if we're started with the terminal it might not have settled,
+            // so the width is quite likely to be in flight.
+            //
+            // This means that `printf %s foo; fish` will overwrite the `foo`,
+            // but that's a smaller problem than having the omitted newline char
+            // appear constantly.
+            //
+            // I can't see a good way around this.
+            if !self.first_prompt {
+                self.screen
+                    .reset_abandoning_line(usize::try_from(termsize_last().width).unwrap());
+            }
+            self.first_prompt = false;
+
+            if !self.conf.event.is_empty() {
+                event::fire_generic(self.parser, self.conf.event.to_owned(), vec![]);
+            }
+            self.exec_prompt(true, false);
+
+            // Start out as initially dirty.
+            self.force_exec_prompt_and_repaint = true;
        }
-        self.first_prompt = false;
-
-        if !self.conf.event.is_empty() {
-            event::fire_generic(self.parser, self.conf.event.to_owned(), vec![]);
-        }
-        self.exec_prompt(true, false);
-
-        // Start out as initially dirty.
-        self.force_exec_prompt_and_repaint = true;

+        self.insert_front(self.parser.pending_keys.take());
        while !self.rls().finished && !check_exit_loop_maybe_warning(Some(self)) {
            if self.handle_char_event(None).is_break() {
                break;
            }
        }

-        if self.conf.transient_prompt {
-            self.exec_prompt(true, true);
-        }
+        if self.conf.prompt_ok {
+            if self.conf.transient_prompt {
+                self.exec_prompt(true, true);
+            }

-        // Redraw the command line. This is what ensures the autosuggestion is hidden, etc. after the
-        // user presses enter.
-        if self.is_repaint_needed(None)
-            || self.screen.scrolled()
-            || self.conf.inputfd != STDIN_FILENO
-        {
-            self.layout_and_repaint_before_execution();
-        }
+            // Redraw the command line. This is what ensures the autosuggestion is hidden, etc. after the
+            // user presses enter.
+            if self.is_repaint_needed(None)
+                || self.screen.scrolled()
+                || self.conf.inputfd != STDIN_FILENO
+            {
+                self.layout_and_repaint_before_execution();
+            }

-        // Finish syntax highlighting (but do not wait forever).
-        if self.rls().finished {
-            self.finish_highlighting_before_exec();
-        }
+            // Finish syntax highlighting (but do not wait forever).
+            if self.rls().finished {
+                self.finish_highlighting_before_exec();
+            }

-        // Emit a newline so that the output is on the line after the command.
-        // But do not emit a newline if the cursor has wrapped onto a new line all its own - see #6826.
-        if !self.screen.cursor_is_wrapped_to_own_line() {
-            let _ = write_to_fd(b"\n", STDOUT_FILENO);
-        }
+            // Emit a newline so that the output is on the line after the command.
+            // But do not emit a newline if the cursor has wrapped onto a new line all its own - see #6826.
+            if !self.screen.cursor_is_wrapped_to_own_line() {
+                let _ = write_to_fd(b"\n", STDOUT_FILENO);
+            }

-        // HACK: If stdin isn't the same terminal as stdout, we just moved the cursor.
-        // For now, just reset it to the beginning of the line.
-        if self.conf.inputfd != STDIN_FILENO {
-            let _ = write_loop(&STDOUT_FILENO, b"\r");
-        }
+            // HACK: If stdin isn't the same terminal as stdout, we just moved the cursor.
+            // For now, just reset it to the beginning of the line.
+            if self.conf.inputfd != STDIN_FILENO {
+                let _ = write_loop(&STDOUT_FILENO, b"\r");
+            }

-        // Ensure we have no pager contents when we exit.
-        if !self.pager.is_empty() {
-            // Clear to end of screen to erase the pager contents.
-            screen_force_clear_to_end();
-            self.clear_pager();
+            // Ensure we have no pager contents when we exit.
+            if !self.pager.is_empty() {
+                // Clear to end of screen to erase the pager contents.
+                screen_force_clear_to_end();
+                self.clear_pager();
+            }
        }

        if EXIT_STATE.load(Ordering::Relaxed) != ExitState::FinishedHandlers as _ {
@@ -2430,10 +2441,12 @@ fn handle_char_event(&mut self, injected_event: Option<CharEvent>) -> ControlFlo
        });

        // If we ran `exit` anywhere, exit.
-        self.exit_loop_requested =
-            self.exit_loop_requested || self.parser.libdata().exit_current_script;
+        self.exit_loop_requested |= self.parser.libdata().exit_current_script;
        self.parser.libdata_mut().exit_current_script = false;
        if self.exit_loop_requested {
+            if !self.conf.prompt_ok {
+                return ControlFlow::Break(());
+            }
            return ControlFlow::Continue(());
        }

@@ -2507,6 +2520,7 @@ fn handle_char_event(&mut self, injected_event: Option<CharEvent>) -> ControlFlo
                ImplicitEvent::Eof => {
                    reader_sighup();
                }
+                ImplicitEvent::Break => return ControlFlow::Break(()),
                ImplicitEvent::CheckExit => (),
                ImplicitEvent::FocusIn => {
                    event::fire_generic(self.parser, L!("fish_focus_in").to_owned(), vec![]);
@@ -2531,16 +2545,31 @@ fn handle_char_event(&mut self, injected_event: Option<CharEvent>) -> ControlFlo
            CharEvent::QueryResponse(query_response) => {
                match query_response {
                    QueryResponseEvent::PrimaryDeviceAttribute => {
-                        if *self.blocking_query() != Some(TerminalQuery::PrimaryDeviceAttribute) {
+                        let mut query = self.blocking_query();
+                        let Some(TerminalQuery::PrimaryDeviceAttribute(tcap_query)) = &*query
+                        else {
                            // Rogue reply.
                            return ControlFlow::Continue(());
-                        }
+                        };
                        if KITTY_KEYBOARD_SUPPORTED.load(Ordering::Relaxed)
                            == Capability::Unknown as _
                        {
                            KITTY_KEYBOARD_SUPPORTED
                                .store(Capability::NotSupported as _, Ordering::Release);
                        }
+                        assert!(
+                            tcap_query.is_none()
+                                || self.parser.pending_user_query.borrow().is_none()
+                        );
+                        if tcap_query.is_some() {
+                            stop_query(query);
+                            // TODO hack
+                            return ControlFlow::Break(());
+                        }
+                        if let Some(queued_query) = self.parser.pending_user_query.take() {
+                            // TODO hack
+                            return (queued_query)(&mut query);
+                        }
                    }
                    QueryResponseEvent::CursorPositionReport(cursor_pos) => {
                        let cursor_pos_query = match &*self.blocking_query() {
@@ -2567,29 +2596,22 @@ fn handle_char_event(&mut self, injected_event: Option<CharEvent>) -> ControlFlo
    }
 }

-fn send_xtgettcap_query(out: &mut impl Output, cap: &'static str) {
+pub(crate) fn query_xtgettcap(out: &mut impl Output, cap: &[u8]) {
+    let command = QueryXtgettcap(cap);
    if should_flog!(reader) {
        let mut tmp = Vec::<u8>::new();
-        tmp.write_command(QueryXtgettcap(cap));
+        tmp.write_command(command.clone());
        FLOG!(
            reader,
-            format!("Sending XTGETTCAP request for {}: {:?}", cap, tmp)
+            sprintf!(
+                "Sending XTGETTCAP request for %s: %s",
+                str2wcstring(cap),
+                escape(&str2wcstring(&tmp))
+            )
        );
    }
-    out.write_command(QueryXtgettcap(cap));
-}
-
-fn query_capabilities_via_dcs(out: &mut impl Output, vars: &dyn Environment) {
-    if vars.get_unless_empty(L!("STY")).is_some()
-        || vars.get_unless_empty(L!("TERM")).is_some_and(|term| {
-            let term = &term.as_list()[0];
-            term == "screen" || term == "screen-256color"
-        })
-    {
-        return;
-    }
    out.write_command(DecsetAlternateScreenBuffer); // enable alternative screen buffer
-    send_xtgettcap_query(out, SCROLL_FORWARD_TERMINFO_CODE);
+    out.write_command(command);
    out.write_command(DecrstAlternateScreenBuffer); // disable alternative screen buffer
 }

@@ -2688,7 +2710,9 @@ fn handle_readline_command(&mut self, c: ReadlineCmd) {

                    let mut outp = Outputter::stdoutput().borrow_mut();
                    if let Some(fish_color_cancel) = self.vars().get(L!("fish_color_cancel")) {
-                        outp.set_text_face(parse_text_face_for_highlight(&fish_color_cancel));
+                        outp.set_text_face(
+                            parse_text_face_for_highlight(&fish_color_cancel).unwrap_or_default(),
+                        );
                    }
                    outp.write_wstr(L!("^C"));
                    outp.reset_text_face();
@@ -3815,9 +3839,6 @@ fn handle_readline_command(&mut self, c: ReadlineCmd) {
                self.clear_screen_and_repaint();
            }
            rl::ScrollbackPush => {
-                if !SCROLL_FORWARD_SUPPORTED.load() {
-                    return;
-                }
                let query = self.blocking_query();
                let Some(query) = &*query else {
                    drop(query);
@@ -3828,7 +3849,7 @@ fn handle_readline_command(&mut self, c: ReadlineCmd) {
                    return;
                };
                match query {
-                    TerminalQuery::PrimaryDeviceAttribute => panic!(),
+                    TerminalQuery::PrimaryDeviceAttribute(_) => panic!(),
                    TerminalQuery::CursorPositionReport(_) => {
                        // TODO: re-queue it I guess.
                        FLOG!(
@@ -4449,8 +4470,6 @@ fn reader_interactive_init(parser: &Parser) {
    parser
        .vars()
        .set_one(L!("_"), EnvMode::GLOBAL, L!("fish").to_owned());
-
-    terminal_protocol_hacks();
 }

 /// Destroy data for interactive use.
@@ -4528,6 +4547,7 @@ pub fn reader_write_title(

 impl<'a> Reader<'a> {
    fn exec_prompt_cmd(&self, prompt_cmd: &wstr, final_prompt: bool) -> Vec<WString> {
+        assert!(self.conf.prompt_ok);
        let mut output = vec![];
        let prompt_cmd = if final_prompt && function::exists(prompt_cmd, self.parser) {
            Cow::Owned(prompt_cmd.to_owned() + L!(" --final-rendering"))
@@ -4540,6 +4560,7 @@ fn exec_prompt_cmd(&self, prompt_cmd: &wstr, final_prompt: bool) -> Vec<WString>

    /// Execute prompt commands based on the provided arguments. The output is inserted into prompt_buff.
    fn exec_prompt(&mut self, full_prompt: bool, final_prompt: bool) {
+        assert!(self.conf.prompt_ok);
        // Suppress fish_trace while in the prompt.
        let _suppress_trace = self.parser.push_scope(|s| s.suppress_fish_trace = true);

--- a/src/terminal.rs
+++ b/src/terminal.rs
@@ -3,13 +3,13 @@
 use crate::common::ToCString;
 use crate::common::{self, escape_string, wcs2string, wcs2string_appending, EscapeStringStyle};
 use crate::future_feature_flags::{self, FeatureFlag};
-use crate::global_safety::RelaxedAtomicBool;
 use crate::screen::{is_dumb, only_grayscale};
 use crate::text_face::{TextFace, TextStyling, UnderlineStyle};
 use crate::threads::MainThread;
 use crate::wchar::prelude::*;
 use crate::FLOGF;
 use bitflags::bitflags;
+use once_cell::sync::OnceCell;
 use std::cell::{RefCell, RefMut};
 use std::env;
 use std::ffi::{CStr, CString};
@@ -83,7 +83,7 @@ pub(crate) enum TerminalCommand<'a> {
    // Commands related to querying (used for backwards-incompatible features).
    QueryPrimaryDeviceAttribute,
    QueryXtversion,
-    QueryXtgettcap(&'static str),
+    QueryXtgettcap(&'a [u8]),

    DecsetAlternateScreenBuffer,
    DecrstAlternateScreenBuffer,
@@ -227,8 +227,7 @@ pub(crate) enum Capability {

 pub(crate) static KITTY_KEYBOARD_SUPPORTED: AtomicU8 = AtomicU8::new(Capability::Unknown as _);

-pub(crate) static SCROLL_FORWARD_SUPPORTED: RelaxedAtomicBool = RelaxedAtomicBool::new(false);
-pub(crate) static SCROLL_FORWARD_TERMINFO_CODE: &str = "indn";
+pub(crate) static XTVERSION: OnceCell<WString> = OnceCell::new();

 pub(crate) fn use_terminfo() -> bool {
    !future_feature_flags::test(FeatureFlag::ignore_terminfo) && TERM.lock().unwrap().is_some()
@@ -349,16 +348,16 @@ fn cursor_move(out: &mut impl Output, direction: CardinalDirection, steps: usize
    true
 }

-fn query_xtgettcap(out: &mut impl Output, cap: &str) -> bool {
+fn query_xtgettcap(out: &mut impl Output, cap: &[u8]) -> bool {
    write_to_output!(out, "\x1bP+q{}\x1b\\", DisplayAsHex(cap));
    true
 }

-struct DisplayAsHex<'a>(&'a str);
+struct DisplayAsHex<'a>(&'a [u8]);

 impl<'a> std::fmt::Display for DisplayAsHex<'a> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        for byte in self.0.bytes() {
+        for byte in self.0 {
            write!(f, "{:x}", byte)?;
        }
        Ok(())
@@ -399,7 +398,6 @@ fn osc_133_command_finished(out: &mut impl Output, exit_status: libc::c_int) ->
 }

 fn scroll_forward(out: &mut impl Output, lines: usize) -> bool {
-    assert!(SCROLL_FORWARD_SUPPORTED.load());
    write_to_output!(out, "\x1b[{}S", lines);
    true
 }
--- a/src/text_face.rs
+++ b/src/text_face.rs
@@ -111,6 +111,12 @@ pub(crate) struct TextFace {
    pub(crate) style: TextStyling,
 }

+impl Default for TextFace {
+    fn default() -> Self {
+        Self::default()
+    }
+}
+
 impl TextFace {
    pub const fn default() -> Self {
        Self {
@@ -131,12 +137,12 @@ pub fn new(fg: Color, bg: Color, underline_color: Color, style: TextStyling) ->
    }
 }

-#[derive(Default)]
+#[derive(Default, Eq, PartialEq)]
 pub(crate) struct SpecifiedTextFace {
    pub(crate) fg: Option<Color>,
    pub(crate) bg: Option<Color>,
    pub(crate) underline_color: Option<Color>,
-    pub(crate) style: TextStyling,
+    pub(crate) style: Option<TextStyling>,
 }

 pub(crate) fn parse_text_face(arguments: &[WString]) -> SpecifiedTextFace {
@@ -167,6 +173,7 @@ pub(crate) enum ParsedArgs<'argarray, 'args> {

 pub(crate) enum ParseError<'args> {
    MissingOptArg,
+    MultipleTracking,
    UnknownColor(&'args wstr),
    UnknownUnderlineStyle(&'args wstr),
    UnknownOption(usize),
@@ -189,6 +196,7 @@ pub(crate) fn parse_text_face_and_options<'argarray, 'args>(
        wopt(L!("reverse"), ArgType::NoArgument, 'r'),
        wopt(L!("help"), ArgType::NoArgument, 'h'),
        wopt(L!("print-colors"), ArgType::NoArgument, 'c'),
+        wopt(L!("track"), ArgType::RequiredArgument, '\x01'),
    ];
    let long_options = &long_options[..long_options.len() - builtin_extra_args];

@@ -210,6 +218,7 @@ pub(crate) fn parse_text_face_and_options<'argarray, 'args>(
    let mut underline_colors = vec![];
    let mut style = TextStyling::default();
    let mut print_color_mode = false;
+    let mut tracking = false;

    let mut w = WGetopter::new(short_options, long_options, argv);
    while let Some(c) = w.next_opt() {
@@ -219,6 +228,12 @@ pub(crate) fn parse_text_face_and_options<'argarray, 'args>(
                    bg_colors.push(bg);
                }
            }
+            '\x01' => {
+                if is_builtin && tracking {
+                    return Err(MultipleTracking);
+                }
+                tracking = true;
+            }
            '\x02' => {
                if let Some(underline_color) = parse_color(w.woptarg.unwrap())? {
                    underline_colors.push(underline_color);
@@ -297,6 +312,6 @@ pub(crate) fn parse_text_face_and_options<'argarray, 'args>(
        fg,
        bg,
        underline_color,
-        style,
+        style: (style != TextStyling::default()).then_some(style),
    }))
 }
--- a/tests/checks/fish_config.fish
+++ b/tests/checks/fish_config.fish
@@ -0,0 +1,51 @@
+#RUN: %fish %s
+
+mkdir $__fish_config_dir/themes
+echo >$__fish_config_dir/themes/foo.theme '
+fish_color_normal cyan
+fish_color_error brred --underline=curly
+'
+
+set -g fish_pager_color_secondary_background custom-value
+fish_config theme choose foo
+
+set -S fish_color_normal
+# CHECK: $fish_color_normal: set in global scope, unexported, with 1 elements
+# CHECK: $fish_color_normal[1]: |cyan|
+set -S fish_pager_color_secondary_background
+# CHECK: $fish_pager_color_secondary_background: set in global scope, unexported, with 0 elements
+
+# Not a default theme, so we allow --underline=curly even if we don't run inside a terminal that
+# advertises support via XTGETTCAP.
+set -S fish_color_error
+# CHECK: $fish_color_error: set in global scope, unexported, with 2 elements
+# CHECK: $fish_color_error[1]: |brred|
+# CHECK: $fish_color_error[2]: |--underline=curly|
+
+
+function change-theme
+    echo >$__fish_config_dir/themes/fake-default.theme 'fish_color_command' $argv
+end
+
+change-theme 'green'
+echo yes | fish_config theme save --track fake-default
+echo $fish_color_command
+# CHECK: green --track=fake-default
+
+change-theme 'green --bold'
+fish_config theme update
+
+echo $fish_color_command
+# CHECK: green --bold --track=fake-default
+
+# Test that we silently update when there is a shadowing global.
+change-theme 'green --italics'
+set -g fish_color_command normal
+fish_config theme update
+set -S fish_color_command
+# CHECK: $fish_color_command: set in global scope, unexported, with 1 elements
+# CHECK: $fish_color_command[1]: |normal|
+# CHECK: $fish_color_command: set in universal scope, unexported, with 3 elements
+# CHECK: $fish_color_command[1]: |green|
+# CHECK: $fish_color_command[2]: |--italics|
+# CHECK: $fish_color_command[3]: |--track=fake-default|
--- a/tests/pexpect_helper.py
+++ b/tests/pexpect_helper.py
@@ -180,7 +180,10 @@ class SpawnedProc(object):
        self.spawn.delaybeforesend = None
        self.prompt_counter = 0
        if env.get("TERM") != "dumb":
-            self.spawn.send("\x1b[?123c")  # Primary Device Attribute
+            self.send_primary_device_attribute()
+
+    def send_primary_device_attribute(self):
+        self.spawn.send("\x1b[?123c")

    def time_since_first_message(self):
        """Return a delta in seconds since the first message, or 0 if this is the first."""
--- a/tests/pexpects/query.py
+++ b/tests/pexpects/query.py
@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+from pexpect_helper import SpawnedProc
+
+import os
+
+env = os.environ.copy()
+env["TERM"] = "foot"
+
+sp = SpawnedProc(env=env)
+send, sendline, sleep, expect_prompt, expect_re, expect_str = (
+    sp.send,
+    sp.sendline,
+    sp.sleep,
+    sp.expect_prompt,
+    sp.expect_re,
+    sp.expect_str,
+)
+expect_prompt()
+
+sendline("function check; and echo true; or echo false; end")
+
+sendline("status xtgettcap am; check")
+expect_str("\x1bP+q616d\x1b\\") # 616d is "am" in hex
+send("\x1bP1+r616d\x1b\\") # success
+sp.send_primary_device_attribute()
+expect_str("true")
+
+sendline("status xtgettcap an; check")
+expect_str("\x1bP+q616e\x1b\\") # 616e is "an" in hex
+send("\x1bP0+r616e\x1b\\") # failure
+sp.send_primary_device_attribute()
+expect_str("false")