diff --git a/src/testdir/test_cdo.in b/src/testdir/test_cdo.in
new file mode 100644
index 0000000..fb80ea1
--- /dev/null
+++ b/src/testdir/test_cdo.in
@@ -0,0 +1,107 @@
+Tests for the :cdo, :cfdo, :ldo and :lfdo commands
+
+STARTTEST
+:so small.vim
+:if !has('quickfix') | e! test.ok | wq! test.out | endif
+
+:call writefile(["Line1", "Line2", "Line3"], 'Xtestfile1')
+:call writefile(["Line1", "Line2", "Line3"], 'Xtestfile2')
+:call writefile(["Line1", "Line2", "Line3"], 'Xtestfile3')
+
+:function RunTests(cchar)
+:  let nl="\n"
+
+:  enew
+:  " Try with an empty list
+:  exe a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+
+:  " Populate the list and then try
+:  exe a:cchar . "getexpr ['non-error 1', 'Xtestfile1:1:3:Line1', 'non-error 2', 'Xtestfile2:2:2:Line2', 'non-error 3', 'Xtestfile3:3:1:Line3']"
+:  exe a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+
+:  " Run command only on selected error lines
+:  enew
+:  exe "2,3" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  " Boundary condition tests
+:  enew
+:  exe "1,1" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  enew
+:  exe "3" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  " Range test commands
+:  enew
+:  exe "%" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  enew
+:  exe "1,$" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  enew
+:  exe a:cchar . 'prev'
+:  exe "." . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  " Invalid error lines test
+:  enew
+:  exe "27" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe "4,5" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+
+:  " Run commands from an unsaved buffer
+:  let v:errmsg=''
+:  enew
+:  setlocal modified
+:  exe "2,2" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  if v:errmsg =~# 'No write since last change'
+:     let g:result .= 'Unsaved file change test passed' . nl
+:  else
+:     let g:result .= 'Unsaved file change test failed' . nl
+:  endif
+
+:  " If the executed command fails, then the operation should be aborted
+:  enew!
+:  let subst_count = 0
+:  exe a:cchar . "do s/Line/xLine/ | let subst_count += 1"
+:  if subst_count == 1 && getline('.') == 'xLine1'
+:     let g:result .= 'Abort command on error test passed' . nl
+:  else
+:     let g:result .= 'Abort command on error test failed' . nl
+:  endif
+
+:  exe "2,2" . a:cchar . "do! let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+
+:  " List with no valid error entries
+:  edit! +2 Xtestfile1
+:  exe a:cchar . "getexpr ['non-error 1', 'non-error 2', 'non-error 3']"
+:  exe a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe "2" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  let v:errmsg=''
+:  exe "%" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe "1,$" . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe "." . a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  let g:result .= v:errmsg
+
+:  " List with only one valid entry
+:  exe a:cchar . "getexpr ['Xtestfile3:3:1:Line3']"
+:  exe a:cchar . "do let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+
+:  " Tests for :cfdo and :lfdo commands
+:  exe a:cchar . "getexpr ['non-error 1', 'Xtestfile1:1:3:Line1', 'Xtestfile1:2:1:Line2', 'non-error 2', 'Xtestfile2:2:2:Line2', 'non-error 3', 'Xtestfile3:2:3:Line2', 'Xtestfile3:3:1:Line3']"
+:  exe a:cchar . "fdo let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe "3" . a:cchar . "fdo let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe "2,3" . a:cchar . "fdo let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe "%" . a:cchar . "fdo let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe "1,$" . a:cchar . "fdo let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:  exe a:cchar . 'pfile'
+:  exe "." . a:cchar . "fdo let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+
+:  " List with only one valid entry
+:  exe a:cchar . "getexpr ['Xtestfile2:2:5:Line2']"
+:  exe a:cchar . "fdo let g:result .= expand('%') . ' ' . line('.') . 'L' . ' ' . col('.') . 'C' . nl"
+:endfunction
+
+:let result=''
+:" Tests for the :cdo quickfix list command
+:call RunTests('c')
+:let result .= "\n"
+:" Tests for the :ldo location list command
+:call RunTests('l')
+
+:edit! test.out
+:0put =result
+:wq!
+ENDTEST
+