vim-patch:8.2.3110: a pattern that matches the cursor position is complicated

Problem:    A pattern that matches the cursor position is bit complicated.
Solution:   Use a dot to indicate the cursor line and column. (Christian
            Brabandt, closes vim/vim#8497, closes vim/vim#8179)
https://github.com/vim/vim/commit/04db26b36000a4677b95403ec94bd11f6cc73975

Also use `n = ++vcol` in regexp_bt.c as `++vcol` alone fails lint.

1 files changed, 25 insertions, 3 deletions

diff --git a/src/nvim/regexp_bt.c b/src/nvim/regexp_bt.c
index 3835a2bbae..7d0b9a7a77 100644
--- a/src/nvim/regexp_bt.c
+++ b/src/nvim/regexp_bt.c
@@ -1578,14 +1578,19 @@ static char_u *regatom(int *flagp)
     }
 
     default:
-      if (ascii_isdigit(c) || c == '<' || c == '>'
-          || c == '\'') {
+      if (ascii_isdigit(c) || c == '<' || c == '>' || c == '\'' || c == '.') {
         uint32_t n = 0;
         int cmp;
+        bool cur = false;
 
         cmp = c;
-        if (cmp == '<' || cmp == '>')
+        if (cmp == '<' || cmp == '>') {
           c = getchr();
+        }
+        if (no_Magic(c) == '.') {
+          cur = true;
+          c = getchr();
+        }
         while (ascii_isdigit(c)) {
           n = n * 10 + (uint32_t)(c - '0');
           c = getchr();
@@ -1602,14 +1607,31 @@ static char_u *regatom(int *flagp)
           }
           break;
         } else if (c == 'l' || c == 'c' || c == 'v') {
+          if (cur && n) {
+            semsg(_(e_regexp_number_after_dot_pos_search), no_Magic(c));
+            rc_did_emsg = true;
+            return NULL;
+          }
           if (c == 'l') {
+            if (cur) {
+              n = curwin->w_cursor.lnum;
+            }
             ret = regnode(RE_LNUM);
             if (save_prev_at_start) {
               at_start = true;
             }
           } else if (c == 'c') {
+            if (cur) {
+              n = curwin->w_cursor.col;
+              n++;
+            }
             ret = regnode(RE_COL);
           } else {
+            if (cur) {
+              colnr_T vcol = 0;
+              getvvcol(curwin, &curwin->w_cursor, NULL, NULL, &vcol);
+              n = ++vcol;
+            }
             ret = regnode(RE_VCOL);
           }
           if (ret == JUST_CALC_SIZE) {