add history append subcommand

share/completions/history.fish

@@ -1,5 +1,5 @@
 # Note that when a completion file is sourced a new block scope is created so `set -l` works.
-set -l __fish_history_all_commands search delete save merge clear clear-session
+set -l __fish_history_all_commands search delete save merge clear clear-session append
 
 complete -c history -s h -l help -d "Display help and exit"
 
@@ -35,3 +35,5 @@ complete -f -c history -n "not __fish_seen_subcommand_from $__fish_history_all_c
     -a clear -d "Clears history file"
 complete -f -c history -n "not __fish_seen_subcommand_from $__fish_history_all_commands" \
     -a clear-session -d "Clears all history from the current session"
+complete -f -c history -n "not __fish_seen_subcommand_from $__fish_history_all_commands" \
+    -a append -d "Appends commands to the history without needing to execute them"

share/functions/history.fish

@@ -70,7 +70,7 @@ function history --description "display or manipulate interactive command histor
     # command. This allows the flags to appear before or after the subcommand.
     if not set -q hist_cmd[1]
         and set -q argv[1]
-        if contains $argv[1] search delete merge save clear clear-session
+        if contains $argv[1] search delete merge save clear clear-session append
             set hist_cmd $argv[1]
             set -e argv[1]
         end
@@ -226,6 +226,13 @@ function history --description "display or manipulate interactive command histor
 
             builtin history clear-session -- $argv
             printf (_ "Command history for session cleared!\n")
+        case append
+            set -l newitem $argv
+            if not set -q argv[1]
+                read -P "Command: " newitem
+            end
+
+            builtin history append -- $newitem
         case '*'
             printf "%ls: unexpected subcommand '%ls'\n" $cmd $hist_cmd
             return 2