vim-patch:7.4.2110 (#5880)

Problem:    When there is an CmdUndefined autocmd then the error for a missing
            command is E464 instead of E492. (Manuel Ortega)
Solution:   Don't let the pointer be NULL.

eac784eced

src/nvim/ex_docmd.c

@@ -1711,7 +1711,7 @@ static char_u * do_one_cmd(char_u **cmdlinep,
     xfree(p);
     // If the autocommands did something and didn't cause an error, try
     // finding the command again.
-    p = (ret && !aborting()) ? find_command(&ea, NULL) : NULL;
+    p = (ret && !aborting()) ? find_command(&ea, NULL) : ea.cmd;
   }
 
   if (p == NULL) {

src/nvim/testdir/test_usercommands.vim

@@ -46,3 +46,33 @@ function Test_cmdmods()
   delcommand MyQCmd
   unlet g:mods
 endfunction
+
+func Test_Ambiguous()
+  command Doit let g:didit = 'yes'
+  command Dothat let g:didthat = 'also'
+  call assert_fails('Do', 'E464:')
+  Doit
+  call assert_equal('yes', g:didit)
+  Dothat
+  call assert_equal('also', g:didthat)
+  unlet g:didit
+  unlet g:didthat
+
+  delcommand Doit
+  Do
+  call assert_equal('also', g:didthat)
+  delcommand Dothat
+endfunc
+
+func Test_CmdUndefined()
+  call assert_fails('Doit', 'E492:')
+  au CmdUndefined Doit :command Doit let g:didit = 'yes'
+  Doit
+  call assert_equal('yes', g:didit)
+  delcommand Doit
+
+  call assert_fails('Dothat', 'E492:')
+  au CmdUndefined * let g:didnot = 'yes'
+  call assert_fails('Dothat', 'E492:')
+  call assert_equal('yes', g:didnot)
+endfunc

src/nvim/version.c

@@ -330,7 +330,7 @@ static int included_patches[] = {
   // 2113,
   2112,
   // 2111,
-  // 2110,
+  2110,
   2109,
   // 2108 NA
   // 2107,