vim-patch:8.0.1123: cannot define a toolbar for a window

Problem:    Cannot define a toolbar for a window.
Solution:   Add a window-local toolbar.
https://github.com/vim/vim/commit/1b9645de3c05f37b5c30e78f999351b0cf486ade

"WinBar" code in "screen.c" was not ported.

Fix https://github.com/neovim/neovim/issues/11513#issuecomment-562012827

1 files changed, 26 insertions, 23 deletions

diff --git a/src/nvim/screen.c b/src/nvim/screen.c
index 9c590efdbc..45c56549c5 100644
--- a/src/nvim/screen.c
+++ b/src/nvim/screen.c
@@ -1741,6 +1741,31 @@ static int advance_color_col(int vcol, int **color_cols)
   return **color_cols >= 0;
 }
 
+// Returns the next grid column.
+static int text_to_screenline(win_T *wp, char_u *text, int col, int off)
+  FUNC_ATTR_NONNULL_ALL
+{
+  int idx = wp->w_p_rl ? off : off + col;
+  LineState s = LINE_STATE(text);
+
+  while (*s.p != NUL) {
+    // TODO(bfredl): cargo-culted from the old Vim code:
+    // if(col + cells > wp->w_width - (wp->w_p_rl ? col : 0)) { break; }
+    // This is obvious wrong. If Vim ever fixes this, solve for "cells" again
+    // in the correct condition.
+    const int maxcells = wp->w_grid.Columns - col - (wp->w_p_rl ? col : 0);
+    const int cells = line_putchar(&s, &linebuf_char[idx], maxcells,
+                                   wp->w_p_rl);
+    if (cells == -1) {
+      break;
+    }
+    col += cells;
+    idx += cells;
+  }
+
+  return col;
+}
+
 // Compute the width of the foldcolumn.  Based on 'foldcolumn' and how much
 // space is available for window "wp", minus "col".
 static int compute_foldcolumn(win_T *wp, int col)
@@ -1942,29 +1967,7 @@ static void fold_line(win_T *wp, long fold_count, foldinfo_T *foldinfo, linenr_T
   // 5. move the text to linebuf_char[off].  Fill up with "fold".
   //    Right-left text is put in columns 0 - number-col, normal text is put
   //    in columns number-col - window-width.
-  int idx;
-
-  if (wp->w_p_rl) {
-    idx = off;
-  } else {
-    idx = off + col;
-  }
-
-  LineState s = LINE_STATE(text);
-
-  while (*s.p != NUL) {
-    // TODO(bfredl): cargo-culted from the old Vim code:
-    // if(col + cells > wp->w_width - (wp->w_p_rl ? col : 0)) { break; }
-    // This is obvious wrong. If Vim ever fixes this, solve for "cells" again
-    // in the correct condition.
-    int maxcells = wp->w_grid.Columns - col - (wp->w_p_rl ? col : 0);
-    int cells = line_putchar(&s, &linebuf_char[idx], maxcells, wp->w_p_rl);
-    if (cells == -1) {
-      break;
-    }
-    col += cells;
-    idx += cells;
-  }
+  col = text_to_screenline(wp, text, col, off);
 
   /* Fill the rest of the line with the fold filler */
   if (wp->w_p_rl)