Add EnterDirectory hook

This hook runs on `change-directory` and is also emitted just before
KakBegin after kakrc has been sourced.

doc/pages/hooks.asciidoc

@@ -147,6 +147,11 @@ name. Hooks with no description will always use an empty string.
 *SessionRenamed* `<old name>:<new name>`::
     executed when a session is renamed using the `rename-session` command
 
+*EnterDirectory* `path`::
+    executed on startup and when the current working directory is changed
+    using the `change-directory` command. The hook param is an absolute path
+    to the new working directory.
+
 *RuntimeError* `error message`::
     an error was encountered while executing a user command
 

src/commands.cc

@@ -2600,13 +2600,15 @@ const CommandDesc change_directory_cmd = {
                                         cursor_pos, FilenameFlags::OnlyDirectories),
                       Completions::Flags::Menu };
         }),
-    [](const ParametersParser& parser, Context&, const ShellContext&)
+    [](const ParametersParser& parser, Context& ctx, const ShellContext&)
     {
         StringView target = parser.positional_count() == 1 ? StringView{parser[0]} : "~";
-        if (chdir(parse_filename(target).c_str()) != 0)
+        auto path = real_path(parse_filename(target));
+        if (chdir(path.c_str()) != 0)
             throw runtime_error(format("unable to change to directory: '{}'", target));
         for (auto& buffer : BufferManager::instance())
             buffer->update_display_name();
+        ctx.hooks().run_hook(Hook::EnterDirectory, path, ctx);
     }
 };
 

src/hook_manager.hh

@@ -50,6 +50,7 @@ enum class Hook
     NextKeyIdle,
     NormalKey,
     ModeChange,
+    EnterDirectory,
     RawKey,
     RegisterModified,
     WinClose,
@@ -97,6 +98,7 @@ constexpr auto enum_desc(Meta::Type<Hook>)
         {Hook::NextKeyIdle, "NextKeyIdle"},
         {Hook::NormalKey, "NormalKey"},
         {Hook::ModeChange, "ModeChange"},
+        {Hook::EnterDirectory, "EnterDirectory"},
         {Hook::RawKey, "RawKey"},
         {Hook::RegisterModified, "RegisterModified"},
         {Hook::WinClose, "WinClose"},

src/main.cc

@@ -842,6 +842,7 @@ int run_server(StringView session, StringView server_init,
 
     {
         Context empty_context{Context::EmptyContextFlag{}};
+        global_scope.hooks().run_hook(Hook::EnterDirectory, real_path("."), empty_context);
         global_scope.hooks().run_hook(Hook::KakBegin, session, empty_context);
     }