vim-patch:9.0.1923: curswant wrong on click with 've' and 'nowrap' set (#25293)

Problem:  curswant wrong on click with 've' and 'nowrap' set
Solution: Add w_leftcol to mouse click column.

closes: vim/vim#13142

https://github.com/vim/vim/commit/db54e989b5cff3cc6442dfc500e3962cc1c0b6d0

3 files changed, 20 insertions, 13 deletions

diff --git a/src/nvim/drawline.c b/src/nvim/drawline.c
index 73021d83a8..65c400299d 100644
--- a/src/nvim/drawline.c
+++ b/src/nvim/drawline.c
@@ -3024,14 +3024,17 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_onl
         linebuf_attr[wlv.off] = wlv.char_attr;
       }
 
-      linebuf_vcol[wlv.off] = wlv.vcol;
-
-      if (wlv.draw_state == WL_FOLD) {
-        linebuf_vcol[wlv.off] = -2;
+      if (wlv.draw_state > WL_STC && wlv.filler_todo <= 0) {
+        linebuf_vcol[wlv.off] = wlv.vcol;
+      } else if (wlv.draw_state == WL_FOLD) {
         if (wlv.n_closing > 0) {
           linebuf_vcol[wlv.off] = -3;
           wlv.n_closing--;
+        } else {
+          linebuf_vcol[wlv.off] = -2;
         }
+      } else {
+        linebuf_vcol[wlv.off] = -1;
       }
 
       if (utf_char2cells(mb_c) > 1) {
@@ -3041,17 +3044,19 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_onl
         // UTF-8: Put a 0 in the second screen char.
         linebuf_char[wlv.off] = 0;
         linebuf_attr[wlv.off] = linebuf_attr[wlv.off - 1];
+
         if (wlv.draw_state > WL_STC && wlv.filler_todo <= 0) {
-          wlv.vcol++;
+          linebuf_vcol[wlv.off] = ++wlv.vcol;
+        } else {
+          linebuf_vcol[wlv.off] = -1;
         }
+
         // When "wlv.tocol" is halfway through a character, set it to the end
         // of the character, otherwise highlighting won't stop.
         if (wlv.tocol == wlv.vcol) {
           wlv.tocol++;
         }
 
-        linebuf_vcol[wlv.off] = wlv.vcol;
-
         if (wp->w_p_rl) {
           // now it's time to backup one cell
           wlv.off--;
diff --git a/src/nvim/grid_defs.h b/src/nvim/grid_defs.h
index 207bf72816..100d648263 100644
--- a/src/nvim/grid_defs.h
+++ b/src/nvim/grid_defs.h
@@ -44,7 +44,7 @@ enum {
 /// attrs[] contains the highlighting attribute for each cell.
 ///
 /// vcols[] contains the virtual columns in the line. -1 means not available
-/// (below last line), MAXCOL means after the end of the line.
+/// or before buffer text, MAXCOL means after the end of the line.
 /// -2 or -3 means in fold column and a mouse click should:
 ///  -2: open a fold
 ///  -3: close a fold
diff --git a/src/nvim/mouse.c b/src/nvim/mouse.c
index 33d7bc2e51..9b09a3fdf3 100644
--- a/src/nvim/mouse.c
+++ b/src/nvim/mouse.c
@@ -1890,13 +1890,15 @@ static void mouse_check_grid(colnr_T *vcolp, int *flagsp)
       }
       colnr_T eol_vcol = gp->vcols[off_r];
       assert(eol_vcol < MAXCOL);
-      // This may be -2 or -3 with 'foldcolumn' and empty line.
-      // In that case set it to -1 as it's just before start of line.
-      eol_vcol = MAX(eol_vcol, -1);
+      if (eol_vcol < 0) {
+        // Empty line or whole line before w_leftcol,
+        // with columns before buffer text
+        eol_vcol = wp->w_leftcol - 1;
+      }
       *vcolp = eol_vcol + (int)(off - off_r);
     } else {
-      // Clicking on an empty line
-      *vcolp = click_col - start_col;
+      // Empty line or whole line before w_leftcol
+      *vcolp = click_col - start_col + wp->w_leftcol;
     }
   } else if (col_from_screen >= 0) {
     // Use the virtual column from vcols[], it is accurate also after