vim-patch:9.0.2018: complete_info() returns wrong index (#25607)

Problem:  complete_info() returns wrong index
Solution: Make order of 'info' in completion_info consistent

Start the iteration from the same point and follow the same direction as
done when assigning the completion numbers. This way we remove the
dependence on the completion direction and make the order of 'info'
consistent.

closes: vim/vim#12230
closes: vim/vim#12971

https://github.com/vim/vim/commit/69fb5afb3bc9da24c2fb0eafb0027ba9c6502fc2

Co-authored-by: LemonBoy <thatlemon@gmail.com>

2 files changed, 95 insertions, 22 deletions

diff --git a/src/nvim/insexpand.c b/src/nvim/insexpand.c
index 5ac40d7238..6f99708e1d 100644
--- a/src/nvim/insexpand.c
+++ b/src/nvim/insexpand.c
@@ -2693,6 +2693,38 @@ static void ins_compl_update_sequence_numbers(void)
   }
 }
 
+static int info_add_completion_info(list_T *li)
+{
+  if (compl_first_match == NULL) {
+    return OK;
+  }
+
+  // Skip the element with the CP_ORIGINAL_TEXT flag at the beginning, in case of
+  // forward completion, or at the end, in case of backward completion.
+  compl_T *match = compl_dir_forward() ? compl_first_match->cp_next
+                                       : compl_first_match->cp_prev->cp_prev;
+  while (match != NULL && !match_at_original_text(match)) {
+    dict_T *di = tv_dict_alloc();
+
+    tv_list_append_dict(li, di);
+    tv_dict_add_str(di, S_LEN("word"), EMPTY_IF_NULL(match->cp_str));
+    tv_dict_add_str(di, S_LEN("abbr"), EMPTY_IF_NULL(match->cp_text[CPT_ABBR]));
+    tv_dict_add_str(di, S_LEN("menu"), EMPTY_IF_NULL(match->cp_text[CPT_MENU]));
+    tv_dict_add_str(di, S_LEN("kind"), EMPTY_IF_NULL(match->cp_text[CPT_KIND]));
+    tv_dict_add_str(di, S_LEN("info"), EMPTY_IF_NULL(match->cp_text[CPT_INFO]));
+    if (match->cp_user_data.v_type == VAR_UNKNOWN) {
+      // Add an empty string for backwards compatibility
+      tv_dict_add_str(di, S_LEN("user_data"), "");
+    } else {
+      tv_dict_add_tv(di, S_LEN("user_data"), &match->cp_user_data);
+    }
+
+    match = compl_dir_forward() ? match->cp_next : match->cp_prev;
+  }
+
+  return OK;
+}
+
 /// Get complete information
 static void get_complete_info(list_T *what_list, dict_T *retdict)
 {
@@ -2738,29 +2770,9 @@ static void get_complete_info(list_T *what_list, dict_T *retdict)
 
   if (ret == OK && (what_flag & CI_WHAT_ITEMS)) {
     list_T *li = tv_list_alloc(get_compl_len());
-
     ret = tv_dict_add_list(retdict, S_LEN("items"), li);
-    if (ret == OK && compl_first_match != NULL) {
-      compl_T *match = compl_first_match;
-      do {
-        if (!match_at_original_text(match)) {
-          dict_T *di = tv_dict_alloc();
-
-          tv_list_append_dict(li, di);
-          tv_dict_add_str(di, S_LEN("word"), EMPTY_IF_NULL(match->cp_str));
-          tv_dict_add_str(di, S_LEN("abbr"), EMPTY_IF_NULL(match->cp_text[CPT_ABBR]));
-          tv_dict_add_str(di, S_LEN("menu"), EMPTY_IF_NULL(match->cp_text[CPT_MENU]));
-          tv_dict_add_str(di, S_LEN("kind"), EMPTY_IF_NULL(match->cp_text[CPT_KIND]));
-          tv_dict_add_str(di, S_LEN("info"), EMPTY_IF_NULL(match->cp_text[CPT_INFO]));
-          if (match->cp_user_data.v_type == VAR_UNKNOWN) {
-            // Add an empty string for backwards compatibility
-            tv_dict_add_str(di, S_LEN("user_data"), "");
-          } else {
-            tv_dict_add_tv(di, S_LEN("user_data"), &match->cp_user_data);
-          }
-        }
-        match = match->cp_next;
-      } while (match != NULL && !is_first_match(match));
+    if (ret == OK) {
+      ret = info_add_completion_info(li);
     }
   }
 
diff --git a/test/old/testdir/test_ins_complete.vim b/test/old/testdir/test_ins_complete.vim
index d9b2abffab..aeceeea9f1 100644
--- a/test/old/testdir/test_ins_complete.vim
+++ b/test/old/testdir/test_ins_complete.vim
@@ -2252,5 +2252,66 @@ func Test_tagfunc_wipes_out_buffer()
   bwipe!
 endfunc
 
+func Test_ins_complete_popup_position()
+  CheckScreendump
+
+  let lines =<< trim END
+      vim9script
+      set nowrap
+      setline(1, ['one', 'two', 'this is line ', 'four'])
+      prop_type_add('test', {highlight: 'Error'})
+      prop_add(3, 0, {
+          text_align: 'above',
+          text: 'The quick brown fox jumps over the lazy dog',
+          type: 'test'
+      })
+  END
+  call writefile(lines, 'XinsPopup', 'D')
+  let buf = RunVimInTerminal('-S XinsPopup', #{rows: 10})
+
+  call term_sendkeys(buf, "3GA\<C-N>")
+  call VerifyScreenDump(buf, 'Test_ins_complete_popup_position_1', {})
+
+  call StopVimInTerminal(buf)
+endfunc
+
+func GetCompleteInfo()
+  let g:compl_info = complete_info()
+  return ''
+endfunc
+
+func Test_complete_info_index()
+  new
+  call setline(1, ["aaa", "bbb", "ccc", "ddd", "eee", "fff"])
+  inoremap <buffer><F5> <C-R>=GetCompleteInfo()<CR>
+
+  " Ensure 'index' in complete_info() is coherent with the 'items' array.
+
+  set completeopt=menu,preview
+  " Search forward.
+  call feedkeys("Go\<C-X>\<C-N>\<F5>\<Esc>_dd", 'tx')
+  call assert_equal("aaa", g:compl_info['items'][g:compl_info['selected']]['word'])
+  call feedkeys("Go\<C-X>\<C-N>\<C-N>\<F5>\<Esc>_dd", 'tx')
+  call assert_equal("bbb", g:compl_info['items'][g:compl_info['selected']]['word'])
+
+  " Search backward.
+  call feedkeys("Go\<C-X>\<C-P>\<F5>\<Esc>_dd", 'tx')
+  call assert_equal("fff", g:compl_info['items'][g:compl_info['selected']]['word'])
+  call feedkeys("Go\<C-X>\<C-P>\<C-P>\<F5>\<Esc>_dd", 'tx')
+  call assert_equal("eee", g:compl_info['items'][g:compl_info['selected']]['word'])
+
+  " Add 'noselect', check that 'selected' is -1 when nothing is selected.
+  set completeopt+=noselect
+  " Search forward.
+  call feedkeys("Go\<C-X>\<C-N>\<F5>\<Esc>_dd", 'tx')
+  call assert_equal(-1, g:compl_info['selected'])
+
+  " Search backward.
+  call feedkeys("Go\<C-X>\<C-P>\<F5>\<Esc>_dd", 'tx')
+  call assert_equal(-1, g:compl_info['selected'])
+
+  set completeopt&
+  bwipe!
+endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab