vim-patch:9.0.0806: 'langmap' works differently when there are modifi…

…ers (neovim#20754)

Problem:    'langmap' works differently when there are modifiers.
Solution:   Only apply 'langmap' to a character where modifiers have no
            effect. (closes vim/vim#11395, closes vim/vim#11404)
vim/vim@49660f5

src/nvim/getchar.c

@@ -1959,16 +1959,28 @@ static int handle_mapping(int *keylenp, bool *timedout, int *mapdepth)
  if (mp->m_keys[0] == tb_c1 && (mp->m_mode & local_State)
  && ((mp->m_mode & MODE_LANGMAP) == 0 || typebuf.tb_maplen == 0)) {
  int nomap = nolmaplen;
- int c2;
+ int modifiers = 0;
  // find the match length of this mapping
  for (mlen = 1; mlen < typebuf.tb_len; mlen++) {
- c2 = typebuf.tb_buf[typebuf.tb_off + mlen];
+ int c2 = typebuf.tb_buf[typebuf.tb_off + mlen];
  if (nomap > 0) {
+ if (nomap == 2 && c2 == KS_MODIFIER) {
+ modifiers = 1;
+ } else if (nomap == 1 && modifiers == 1) {
+ modifiers = c2;
+ }
  nomap--;
- } else if (c2 == K_SPECIAL) {
- nomap = 2;
  } else {
- LANGMAP_ADJUST(c2, true);
+ if (c2 == K_SPECIAL) {
+ nomap = 2;
+ } else if (merge_modifiers(c2, &modifiers) == c2) {
+ // Only apply 'langmap' if merging modifiers into
+ // the key will not result in another character,
+ // so that 'langmap' behaves consistently in
+ // different terminals and GUIs.
+ LANGMAP_ADJUST(c2, true);
+ }
+ modifiers = 0;
  }
  if (mp->m_keys[mlen] != c2) {
  break;

src/nvim/testdir/test_langmap.vim

@@ -49,6 +49,41 @@ func Test_langmap()
  call feedkeys(';', 'tx')
  call assert_equal(5, col('.'))
 
+ set langmap=RL
+ let g:counter = 0
+ nnoremap L;L <Cmd>let g:counter += 1<CR>
+ nnoremap <C-L> <Cmd>throw 'This mapping shoud not be triggered'<CR>
+
+ " 'langmap' is applied to keys without modifiers when matching a mapping
+ call feedkeys('R;R', 'tx')
+ call assert_equal(1, g:counter)
+ nunmap L;L
+ unlet g:counter
+
+ delete
+ call assert_equal('', getline(1))
+ undo
+ call assert_equal('Hello World', getline(1))
+ " 'langmap' does not change Ctrl-R to Ctrl-L for consistency
+ call feedkeys("\<*C-R>", 'tx')
+ call assert_equal('', getline(1))
+
+ set langmap=6L
+ undo
+ setlocal bufhidden=hide
+ let oldbuf = bufnr()
+ enew
+ call assert_notequal(oldbuf, bufnr())
+ " 'langmap' does not change Ctrl-6 to Ctrl-L for consistency
+ " Ctrl-6 becomes Ctrl-^ after merging the Ctrl modifier
+ call feedkeys("\<*C-6>", 'tx')
+ call assert_equal(oldbuf, bufnr())
+ setlocal bufhidden&
+
+ nunmap <C-L>
+
  set langmap&
  quit!
 endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab