Merge pull request #18918 from neovim/backport-18917-to-release-0.7

[Backport release-0.7] fix(input): fix macro recording with ALT and special key

src/nvim/getchar.c

@@ -1006,6 +1006,7 @@ int ins_char_typebuf(int c, int modifier)
     buf[len + 1] = (char_u)K_SECOND(c);
     buf[len + 2] = (char_u)K_THIRD(c);
     buf[len + 3] = NUL;
+    len += 3;
   } else {
     char_u *end = add_char2buf(c, buf + len);
     *end = NUL;

test/functional/editor/meta_key_spec.lua

@@ -106,14 +106,35 @@ describe('meta-keys #8226 #13042', function()
   end)
 
   it('ALT/META when recording a macro #13235', function()
+    command('inoremap <M-Esc> <lt>M-ESC>')
     feed('ifoo<CR>bar<CR>baz<Esc>gg0')
     -- <M-"> is reinterpreted as <Esc>"
     feed('qrviw"ayC// This is some text: <M-">apq')
     expect([[
       // This is some text: foo
       bar
       baz]])
-    -- Should not insert an extra double quote when replaying
+    -- Should not insert an extra double quote or trigger <M-Esc> when replaying
+    feed('j0@rj0@@')
+    expect([[
+      // This is some text: foo
+      // This is some text: bar
+      // This is some text: baz]])
+    command('%delete')
+  end)
+
+  it('ALT/META with special key when recording a macro', function()
+    command('inoremap <M-Esc> <lt>M-ESC>')
+    command('noremap <S-Tab> "')
+    command('noremap! <S-Tab> "')
+    feed('ifoo<CR>bar<CR>baz<Esc>gg0')
+    -- <M-S-Tab> is reinterpreted as <Esc><S-Tab>
+    feed('qrviw<S-Tab>ayC// This is some text: <M-S-Tab>apq')
+    expect([[
+      // This is some text: foo
+      bar
+      baz]])
+    -- Should not insert an extra double quote or trigger <M-Esc> when replaying
     feed('j0@rj0@@')
     expect([[
       // This is some text: foo