vim-patch:9.0.1774: no support for custom cmdline completion (#24808)

Problem:  no support for custom cmdline completion
Solution: Add new vimscript functions

Add the following two functions:
- getcmdcompltype() returns custom and customlist functions

- getcompletion() supports both custom and customlist

closes: vim/vim#12228

https://github.com/vim/vim/commit/92997dda789ad8061841128cbc99b15ec0374411

Co-authored-by: Shougo Matsushita <Shougo.Matsu@gmail.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/nvim/cmdexpand.c b/src/nvim/cmdexpand.c
index eb9394c8ff..9470f77ab5 100644
--- a/src/nvim/cmdexpand.c
+++ b/src/nvim/cmdexpand.c
@@ -3515,12 +3515,34 @@ void f_getcompletion(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   ExpandInit(&xpc);
   xpc.xp_pattern = (char *)pattern;
   xpc.xp_pattern_len = strlen(xpc.xp_pattern);
+  xpc.xp_line = (char *)pattern;
+
   xpc.xp_context = cmdcomplete_str_to_type(type);
   if (xpc.xp_context == EXPAND_NOTHING) {
     semsg(_(e_invarg2), type);
     return;
   }
 
+  if (xpc.xp_context == EXPAND_USER_DEFINED) {
+    // Must be "custom,funcname" pattern
+    if (strncmp(type, "custom,", 7) != 0) {
+      semsg(_(e_invarg2), type);
+      return;
+    }
+
+    xpc.xp_arg = (char *)(type + 7);
+  }
+
+  if (xpc.xp_context == EXPAND_USER_LIST) {
+    // Must be "customlist,funcname" pattern
+    if (strncmp(type, "customlist,", 11) != 0) {
+      semsg(_(e_invarg2), type);
+      return;
+    }
+
+    xpc.xp_arg = (char *)(type + 11);
+  }
+
   if (xpc.xp_context == EXPAND_MENUS) {
     set_context_in_menu_cmd(&xpc, "menu", xpc.xp_pattern, false);
     xpc.xp_pattern_len = strlen(xpc.xp_pattern);