vim-patch:8.2.1907: complete_info().selected may be wrong

Problem:    Complete_info().selected may be wrong.
Solution:   Update cp_number if it was never set. (issue vim/vim#6945)
https://github.com/vim/vim/commit/f9d51354de069dddc049b9e109b1932c92e5aee6

Misc changes:

For variables and function parameters that use "Direction" enum values,
update their type from from "int" to "Direction".
It is hard to review function parameters that must accept
"Direction" enum values only.

1 files changed, 66 insertions, 52 deletions

diff --git a/src/nvim/edit.c b/src/nvim/edit.c
index d6668439c5..7fefa8520a 100644
--- a/src/nvim/edit.c
+++ b/src/nvim/edit.c
@@ -196,8 +196,8 @@ static int ctrl_x_mode = CTRL_X_NORMAL;
 
 static int compl_matches = 0;
 static char_u     *compl_pattern = NULL;
-static int compl_direction = FORWARD;
-static int compl_shows_dir = FORWARD;
+static Direction compl_direction = FORWARD;
+static Direction compl_shows_dir = FORWARD;
 static int compl_pending = 0;               // > 1 for postponed CTRL-N
 static pos_T compl_startpos;
 static colnr_T compl_col = 0;               /* column where the text starts
@@ -2156,7 +2156,7 @@ static bool ins_compl_accept_char(int c)
 ///
 /// @param[in]  cont_s_ipos  next ^X<> will set initial_pos
 int ins_compl_add_infercase(char_u *str_arg, int len, bool icase, char_u *fname,
-                            int dir, bool cont_s_ipos)
+                            Direction dir, bool cont_s_ipos)
   FUNC_ATTR_NONNULL_ARG(1)
 {
   char_u *str = str_arg;
@@ -2308,7 +2308,7 @@ static int ins_compl_add(char_u *const str, int len,
   FUNC_ATTR_NONNULL_ARG(1)
 {
   compl_T     *match;
-  int dir = (cdir == kDirectionNotSet ? compl_direction : cdir);
+  const Direction dir = (cdir == kDirectionNotSet ? compl_direction : cdir);
   int flags = flags_arg;
 
   os_breakcheck();
@@ -2511,7 +2511,7 @@ static void ins_compl_add_matches(int num_matches, char_u **matches, int icase)
   FUNC_ATTR_NONNULL_ALL
 {
   int add_r = OK;
-  int dir = compl_direction;
+  Direction dir = compl_direction;
 
   for (int i = 0; i < num_matches && add_r != FAIL; i++) {
     if ((add_r = ins_compl_add(matches[i], -1, NULL, NULL, false, NULL, dir,
@@ -2864,7 +2864,7 @@ ins_compl_dictionaries (
   char_u      **files;
   int count;
   int save_p_scs;
-  int dir = compl_direction;
+  Direction dir = compl_direction;
 
   if (*dict == NUL) {
     /* When 'dictionary' is empty and spell checking is enabled use
@@ -2945,7 +2945,10 @@ theend:
   xfree(buf);
 }
 
-static void ins_compl_files(int count, char_u **files, int thesaurus, int flags, regmatch_T *regmatch, char_u *buf, int *dir)
+static void ins_compl_files(int count, char_u **files, int thesaurus,
+                            int flags, regmatch_T *regmatch, char_u *buf,
+                            Direction *dir)
+  FUNC_ATTR_NONNULL_ARG(2, 7)
 {
   char_u      *ptr;
   int i;
@@ -3137,6 +3140,56 @@ bool ins_compl_active(void)
   return compl_started;
 }
 
+static void ins_compl_update_sequence_numbers(void)
+{
+  int number = 0;
+  compl_T *match;
+
+  if (compl_direction == FORWARD) {
+    // search backwards for the first valid (!= -1) number.
+    // This should normally succeed already at the first loop
+    // cycle, so it's fast!
+    for (match = compl_curr_match->cp_prev;
+         match != NULL && match != compl_first_match;
+         match = match->cp_prev) {
+      if (match->cp_number != -1) {
+        number = match->cp_number;
+        break;
+      }
+    }
+    if (match != NULL) {
+      // go up and assign all numbers which are not assigned yet
+      for (match = match->cp_next;
+           match != NULL && match->cp_number == -1;
+           match = match->cp_next) {
+        match->cp_number = ++number;
+      }
+    }
+  } else {  // BACKWARD
+    assert(compl_direction == BACKWARD);
+    // search forwards (upwards) for the first valid (!= -1)
+    // number.  This should normally succeed already at the
+    // first loop cycle, so it's fast!
+    for (match = compl_curr_match->cp_next;
+         match != NULL && match != compl_first_match;
+         match = match->cp_next) {
+      if (match->cp_number != -1) {
+        number = match->cp_number;
+        break;
+      }
+    }
+    if (match != NULL) {
+      // go down and assign all numbers which are not
+      // assigned yet
+      for (match = match->cp_prev;
+           match && match->cp_number == -1;
+           match = match->cp_prev) {
+        match->cp_number = ++number;
+      }
+    }
+  }
+}
+
 // Get complete information
 void get_complete_info(list_T *what_list, dict_T *retdict)
 {
@@ -3214,6 +3267,9 @@ void get_complete_info(list_T *what_list, dict_T *retdict)
   }
 
   if (ret == OK && (what_flag & CI_WHAT_SELECTED)) {
+    if (compl_curr_match != NULL && compl_curr_match->cp_number == -1) {
+      ins_compl_update_sequence_numbers();
+    }
     ret = tv_dict_add_nr(retdict, S_LEN("selected"),
                          (compl_curr_match != NULL)
                          ? compl_curr_match->cp_number - 1 : -1);
@@ -3865,7 +3921,7 @@ theend:
  */
 static void ins_compl_add_list(list_T *const list)
 {
-  int dir = compl_direction;
+  Direction dir = compl_direction;
 
   // Go through the List with matches and add each of them.
   TV_LIST_ITER(list, li, {
@@ -5242,53 +5298,11 @@ static int ins_complete(int c, bool enable_pum)
     } else if (compl_curr_match->cp_next == compl_curr_match->cp_prev) {
       edit_submode_extra = (char_u *)_("The only match");
       edit_submode_highl = HLF_COUNT;
-      compl_curr_match->cp_number = 0;
+      compl_curr_match->cp_number = 1;
     } else {
       // Update completion sequence number when needed.
       if (compl_curr_match->cp_number == -1) {
-        int number = 0;
-        compl_T         *match;
-
-        if (compl_direction == FORWARD) {
-          /* search backwards for the first valid (!= -1) number.
-           * This should normally succeed already at the first loop
-           * cycle, so it's fast! */
-          for (match = compl_curr_match->cp_prev; match != NULL
-               && match != compl_first_match;
-               match = match->cp_prev)
-            if (match->cp_number != -1) {
-              number = match->cp_number;
-              break;
-            }
-          if (match != NULL)
-            /* go up and assign all numbers which are not assigned
-             * yet */
-            for (match = match->cp_next;
-                 match != NULL && match->cp_number == -1;
-                 match = match->cp_next)
-              match->cp_number = ++number;
-        } else {  // BACKWARD
-          // search forwards (upwards) for the first valid (!= -1)
-          // number.  This should normally succeed already at the
-          // first loop cycle, so it's fast!
-          for (match = compl_curr_match->cp_next;
-               match != NULL && match != compl_first_match;
-               match = match->cp_next) {
-            if (match->cp_number != -1) {
-              number = match->cp_number;
-              break;
-            }
-          }
-          if (match != NULL) {
-            // go down and assign all numbers which are not
-            // assigned yet
-            for (match = match->cp_prev;
-                 match && match->cp_number == -1;
-                 match = match->cp_prev) {
-              match->cp_number = ++number;
-            }
-          }
-        }
+        ins_compl_update_sequence_numbers();
       }
 
       /* The match should always have a sequence number now, this is