Allow help to open the tutorial

This is unambiguous because all the anchors in tutorial.html begin
with "tut".

CHANGELOG.md

@@ -10,6 +10,7 @@
  -
 - Improved completions for `killall` (#4052), `ln` (#4090) and `zypper` (#4079).
 - Implemented `string lower` and `string upper` (#4080).
+- `help` can now open the tutorial.
 
 ---
 

share/completions/help.fish

@@ -72,3 +72,31 @@ complete -c help -x -a vi-mode --description 'Vi mode commands'
 complete -c help -x -a vi-mode-command --description 'Command mode'
 complete -c help -x -a vi-mode-insert --description 'Insert mode'
 complete -c help -x -a vi-mode-visual --description 'Visual mode'
+
+# Tutorial
+complete -c help -x -a tutorial --description 'Tutorial'
+complete -c help -x -a tut_autoload --description 'Autoloading Functions'
+complete -c help -x -a tut_autosuggestions --description 'Autosuggestions'
+complete -c help -x -a tut_combiners --description 'Combiners (And, Or, Not)'
+complete -c help -x -a tut_command_substitutions --description 'Command Substitutions'
+complete -c help -x -a tut_conditionals --description 'Conditionals (If, Else, Switch)'
+complete -c help -x -a tut_exit_status --description 'Exit Status'
+complete -c help -x -a tut_exports --description 'Exports (Shell Variables)'
+complete -c help -x -a tut_functions --description 'Functions'
+complete -c help -x -a tut_getting_help --description 'Getting Help'
+complete -c help -x -a tut_learning_Fish --description 'Learning fish'
+complete -c help -x -a tut_lists --description 'Lists'
+complete -c help -x -a tut_loops --description 'Loops'
+complete -c help -x -a tut_more --description 'Ready for more?'
+complete -c help -x -a tut_path --description '$PATH'
+complete -c help -x -a tut_pipes_and_redirections --description 'Pipes and Redirections'
+complete -c help -x -a tut_prompt --description 'Prompt'
+complete -c help -x -a tut_running_commands --description 'Running Commands'
+complete -c help -x -a tut_semicolon --description 'Separating Commands (Semicolon)'
+complete -c help -x -a tut_startup --description "Startup (Where's .bashrc?)"
+complete -c help -x -a tut_syntax_highlighting --description 'Syntax Highlighting'
+complete -c help -x -a tut_tab_completions --description 'Tab Completions'
+complete -c help -x -a tut_universal --description 'Universal Variables'
+complete -c help -x -a tut_variables --description 'Variables'
+complete -c help -x -a tut_why_fish --description 'Why fish?'
+complete -c help -x -a tut_wildcards --description 'Wildcards'

share/functions/help.fish

@@ -89,8 +89,6 @@ function help --description 'Show help for the fish shell'
     set -l fish_help_item $argv[1]
 
     switch "$fish_help_item"
-        case ""
-            set fish_help_page index.html
         case "."
             set fish_help_page "commands.html\#source"
         case globbing
@@ -99,7 +97,13 @@ function help --description 'Show help for the fish shell'
             set fish_help_page "commands.html\#$fish_help_item"
         case $help_topics
             set fish_help_page "index.html\#$fish_help_item"
+        case 'tut_*'
+            set fish_help_page "tutorial.html\#$fish_help_item"
+        case tutorial
+            set fish_help_page "tutorial.html"
         case "*"
+            # If $fish_help_item is empty, this will fail,
+            # and $fish_help_page will end up as index.html
             if type -q -f $fish_help_item
                 # Prefer to use fish's man pages, to avoid
                 # the annoying useless "builtin" man page bash