Align eskk#is_enabled() with keep-state mappings to fix command-line toggle desync

autoload/eskk.vim

@@ -1842,8 +1842,16 @@ endfunction "}}}
 
 " Enable/Disable IM
 function! eskk#is_enabled() abort "{{{
-    return eskk#is_initialized()
-                \   && &iminsert is 1
+    if !eskk#is_initialized()
+        return 0
+    endif
+    if &iminsert is 1
+        return 1
+    endif
+    return has_key(eskk#get_buffer_instance(), 'prev_lang_keys')
+endfunction "}}}
+function! s:is_im_enabled_in_current_mode() abort "{{{
+    return mode() ==# 'c' ? (&imsearch ==# 1) : (&iminsert ==# 1)
 endfunction "}}}
 function! eskk#toggle() abort "{{{
     if !eskk#is_initialized()
@@ -1860,6 +1868,16 @@ function! eskk#enable() abort "{{{
     if eskk#is_enabled()
         " Initialize mode.
         call eskk#set_mode(g:eskk#initial_mode)
+        if mode() =~# '^[ic]$'
+            if !s:is_im_enabled_in_current_mode()
+                " NOTE: Vim can't enter lang-mode immediately
+                " in insert-mode or commandline-mode.
+                " We have to use i_CTRL-^ .
+                setlocal iminsert=1 imsearch=1
+                redrawstatus
+                return "\<C-^>"
+            endif
+        endif
         return ''
     endif
     if exists('b:skk_on') && b:skk_on
@@ -1946,10 +1964,11 @@ function! eskk#disable() abort "{{{
         " NOTE: Vim can't escape lang-mode immediately
         " in insert-mode or commandline-mode.
         " We have to use i_CTRL-^ .
+        let was_im_enabled = s:is_im_enabled_in_current_mode()
         setlocal iminsert=0 imsearch=0
         redrawstatus
         let kakutei_str = eskk#get_preedit().generate_kakutei_str()
-        let ret = kakutei_str . "\<C-^>"
+        let ret = kakutei_str . (was_im_enabled ? "\<C-^>" : '')
         call s:dict_update_rank()
     else
         setlocal iminsert=0 imsearch=0

test/02-input/05-keep-state-toggle.vim

@@ -0,0 +1,47 @@
+" vim:foldmethod=marker:fen:
+scriptencoding utf-8
+
+" Saving 'cpoptions' {{{
+let s:save_cpo = &cpo
+set cpo&vim
+" }}}
+
+
+function! s:run() abort "{{{
+  let save_iminsert = &l:iminsert
+  try
+    call eskk#enable()
+    let inst = eskk#get_buffer_instance()
+    OK has_key(inst, 'prev_lang_keys')
+    OK eskk#is_enabled()
+
+    let &l:iminsert = 0
+    OK eskk#is_enabled()
+
+    call eskk#toggle()
+    let inst = eskk#get_buffer_instance()
+    OK !has_key(inst, 'prev_lang_keys')
+    OK !eskk#is_enabled()
+
+    call eskk#enable()
+    let &l:iminsert = 0
+    let &l:imsearch = 1
+    OK eskk#is_enabled()
+
+    call eskk#disable()
+    let inst = eskk#get_buffer_instance()
+    OK !has_key(inst, 'prev_lang_keys')
+    OK !eskk#is_enabled()
+  finally
+    call eskk#disable()
+    let &l:iminsert = save_iminsert
+  endtry
+endfunction "}}}
+
+call s:run()
+Done
+
+
+" Restore 'cpoptions' {{{
+let &cpo = s:save_cpo
+" }}}