From 8af3d641daf03610c824ca4e0dffa07db297cb5b Mon Sep 17 00:00:00 2001
From: zeertzjq <zeertzjq@outlook.com>
Date: Fri, 22 Jul 2022 06:41:51 +0800
Subject: [PATCH] fix(grid): don't use utfc_ptr2char_len() when printing until
 NUL (#19456)

---
 src/nvim/grid.c                        | 21 +++++++++------------
 test/functional/ui/statusline_spec.lua |  9 +++++++++
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/src/nvim/grid.c b/src/nvim/grid.c
index 1268f987e1..72e85c425d 100644
--- a/src/nvim/grid.c
+++ b/src/nvim/grid.c
@@ -230,16 +230,12 @@ void grid_puts_len(ScreenGrid *grid, char_u *text, int textlen, int row, int col
          && *ptr != NUL) {
     c = *ptr;
     // check if this is the first byte of a multibyte
-    if (len > 0) {
-      mbyte_blen = utfc_ptr2len_len(ptr, (int)((text + len) - ptr));
-    } else {
-      mbyte_blen = utfc_ptr2len((char *)ptr);
-    }
-    if (len >= 0) {
-      u8c = utfc_ptr2char_len(ptr, u8cc, (int)((text + len) - ptr));
-    } else {
-      u8c = utfc_ptr2char(ptr, u8cc);
-    }
+    mbyte_blen = len > 0
+      ? utfc_ptr2len_len(ptr, (int)((text + len) - ptr))
+      : utfc_ptr2len((char *)ptr);
+    u8c = len >= 0
+      ? utfc_ptr2char_len(ptr, u8cc, (int)((text + len) - ptr))
+      : utfc_ptr2char(ptr, u8cc);
     mbyte_cells = utf_char2cells(u8c);
     if (p_arshape && !p_tbidi && ARABIC_CHAR(u8c)) {
       // Do Arabic shaping.
@@ -248,8 +244,9 @@ void grid_puts_len(ScreenGrid *grid, char_u *text, int textlen, int row, int col
         nc = NUL;
         nc1 = NUL;
       } else {
-        nc = utfc_ptr2char_len(ptr + mbyte_blen, pcc,
-                               (int)((text + len) - ptr - mbyte_blen));
+        nc = len >= 0
+          ? utfc_ptr2char_len(ptr + mbyte_blen, pcc, (int)((text + len) - ptr - mbyte_blen))
+          : utfc_ptr2char(ptr + mbyte_blen, pcc);
         nc1 = pcc[0];
       }
       pc = prev_c;
diff --git a/test/functional/ui/statusline_spec.lua b/test/functional/ui/statusline_spec.lua
index 2ffd3149a6..760760150c 100644
--- a/test/functional/ui/statusline_spec.lua
+++ b/test/functional/ui/statusline_spec.lua
@@ -1,5 +1,6 @@
 local helpers = require('test.functional.helpers')(after_each)
 local Screen = require('test.functional.ui.screen')
+local assert_alive = helpers.assert_alive
 local clear = helpers.clear
 local command = helpers.command
 local feed = helpers.feed
@@ -368,3 +369,11 @@ describe('global statusline', function()
     eq(1, meths.get_option('cmdheight'))
   end)
 end)
+
+it('statusline does not crash if it has Arabic characters #19447', function()
+  clear()
+  meths.set_option('statusline', 'غً')
+  meths.set_option('laststatus', 2)
+  command('redraw!')
+  assert_alive()
+end)