Continue passing -X / --no-init for less < v530

The less -F / --quit-if-one-screen option is buggy before v530. To work
around this, pass --no-init less versions older than 530.

The --no-init option was previously passed; it was removed in d15a51897d
for mouse support. Unfortunately it looks like we can't have mouse
support and --quit-if-one-screen on macOS shipped less (version 487).

It's worth fixing this because otherwise history and help is just not
printed on stock macOS.

Relevant is https://unix.stackexchange.com/questions/107315/less-quit-if-one-screen-without-no-init

Fixes #8157.

CHANGELOG.rst

@@ -78,6 +78,7 @@ Interactive improvements
 - ``cd ""`` no longer crashes fish (:issue:`8147`).
 - Running a commandline consisting of just spaces now deletes an ephemeral (starting with space) history item again (:issue:`8232`).
 - Command substitutions no longer respect job control, instead running inside fish's own process group (:issue:`8172`). This more closely matches other shells, and improves :kbd:`Control-C` reliability inside a command substitution.
+- ``history`` and ``__fish_print_help`` now properly support ``less`` before version 530, including the version that ships with macOS. (:issue:`8157`).
 
 New or improved bindings
 ^^^^^^^^^^^^^^^^^^^^^^^^

share/functions/__fish_print_help.fish

@@ -119,13 +119,21 @@ function __fish_print_help --description "Print help message for the specified f
             not isatty stdout
             and set pager cat # cannot use a builtin here
             # similar to man, but add -F to quit paging when the help output is brief (#6227)
+            # Also set -X for less < v530, see #8157.
+            set -l lessopts isRF
+            if test "$(less --version | string match -rg 'less (\d+)')" -lt 530 2>/dev/null
+                set lessopts "$lessopts"X
+            end
+
             not set -qx LESS
-            and set -xl LESS isRF
+            and set -xl LESS $lessopts
+
             # less options:
             # -i (--ignore-case) search case-insensitively, like man
             # -s (--squeeze-blank-lines) not strictly necessary since we already do that above
             # -R (--RAW-CONTROL-CHARS) to display colors and such
             # -F (--quit-if-one-screen) to maintain the non-paging behavior for small outputs
+            # -X (--no-init) do not clear the screen, necessary for less < v530 or else short output is dropped
             $pager
         end
 end

share/functions/history.fish

@@ -90,8 +90,13 @@ function history --description "display or manipulate interactive command histor
 
                 # If the user hasn't preconfigured less with the $LESS environment variable,
                 # we do so to have it behave like cat if output fits on one screen.
-                not set -qx LESS
-                and set -x LESS --quit-if-one-screen
+                if not set -qx LESS
+                    set -x LESS --quit-if-one-screen
+                    # Also set --no-init for less < v530, see #8157.
+                    if test "$(less --version | string match -rg 'less (\d+)')" -lt 530 2>/dev/null
+                        set -x LESS $LESS --no-init
+                    end
+                end
                 not set -qx LV # ask the pager lv not to strip colors
                 and set -x LV -c