When stop CLPUM, characters are deleted under the cursor until the end of the command-line.

[h-east]

How to reproduce:

• Start pure Vim with enable clpum.
  $ vim -N -u NONE -c "set clpum"
• Input below.
  :abcde<C-B>set w
• Start CLPUM and insert second item.
  <Tab><Tab>
• Stop CLPUM and go back to the originally typed text.
  <C-E>

Expected behavior:

• The following characters are displayed on the command line. (| is cursor)
  :set w|abcde

Actual behavior:

• Displayed this. Where is abcde gone?
  :set w|

[h-east]

Done.