vim-patch:7.4.1697

Problem:    Display problems when the 'ambiwidth' and 'emoji' options are not
            set properly or the terminal doesn't behave as expected.
Solution:   After drawing an ambiguous width character always position the
            cursor.

https://github.com/vim/vim/commit/cb0700844c1274fe8bc0ceaffaee0ad21c406f30

2 files changed, 9 insertions, 7 deletions

diff --git a/src/nvim/mbyte.c b/src/nvim/mbyte.c
index 2978171051..c08b9e8fcf 100644
--- a/src/nvim/mbyte.c
+++ b/src/nvim/mbyte.c
@@ -1724,12 +1724,11 @@ int utf_class(int c)
   return 2;
 }
 
-/*
- * Code for Unicode case-dependent operations.  Based on notes in
- * http://www.unicode.org/Public/UNIDATA/CaseFolding.txt
- * This code uses simple case folding, not full case folding.
- * Last updated for Unicode 5.2.
- */
+int utf_ambiguous_width(int c)
+{
+  return c >= 0x80 && (intable(ambiguous, ARRAY_SIZE(ambiguous), c)
+                       || intable(emoji_all, ARRAY_SIZE(emoji_all), c));
+}
 
 /*
  * Generic conversion function for case operations.
diff --git a/src/nvim/ui.c b/src/nvim/ui.c
index b8d44cbcf8..648d633e07 100644
--- a/src/nvim/ui.c
+++ b/src/nvim/ui.c
@@ -397,7 +397,10 @@ static void send_output(uint8_t **ptr)
     size_t clen = (size_t)mb_ptr2len(p);
     UI_CALL(put, p, (size_t)clen);
     col++;
-    if (mb_ptr2cells(p) > 1) {
+    if (utf_ambiguous_width(*p)) {
+      pending_cursor_update = true;
+      flush_cursor_update();
+    } else if (mb_ptr2cells(p) > 1) {
       // double cell character, blank the next cell
       UI_CALL(put, NULL, 0);
       col++;