4 files changed, 22 insertions, 8 deletions
diff --git a/src/nvim/api/extmark.c b/src/nvim/api/extmark.c
index 80bd88c4ee..3a968f07ab 100644
--- a/src/nvim/api/extmark.c
+++ b/src/nvim/api/extmark.c
@@ -106,9 +106,12 @@ static Array extmark_to_array(ExtmarkInfo extmark, bool id, bool add_dict)
   if (add_dict) {
     Dictionary dict = ARRAY_DICT_INIT;
 
+    PUT(dict, "right_gravity", BOOLEAN_OBJ(extmark.right_gravity));
+
     if (extmark.end_row >= 0) {
       PUT(dict, "end_row", INTEGER_OBJ(extmark.end_row));
       PUT(dict, "end_col", INTEGER_OBJ(extmark.end_col));
+      PUT(dict, "end_right_gravity", BOOLEAN_OBJ(extmark.end_right_gravity));
     }
 
     Decoration *decor = &extmark.decor;
diff --git a/src/nvim/extmark.c b/src/nvim/extmark.c
index cee657c8c9..48e57e20e1 100644
--- a/src/nvim/extmark.c
+++ b/src/nvim/extmark.c
@@ -305,12 +305,14 @@ ExtmarkInfoArray extmark_get(buf_T *buf, uint32_t ns_id, int l_row, colnr_T l_co
     }
 
     if (mark.ns == ns_id) {
-      mtpos_t endpos = marktree_get_altpos(buf->b_marktree, mark, NULL);
+      mtkey_t end = marktree_get_alt(buf->b_marktree, mark, NULL);
       kv_push(array, ((ExtmarkInfo) { .ns_id = mark.ns,
                                       .mark_id = mark.id,
                                       .row = mark.pos.row, .col = mark.pos.col,
-                                      .end_row = endpos.row,
-                                      .end_col = endpos.col,
+                                      .end_row = end.pos.row,
+                                      .end_col = end.pos.col,
+                                      .right_gravity = mt_right(mark),
+                                      .end_right_gravity = mt_right(end),
                                       .decor = get_decor(mark) }));
     }
 next_mark:
@@ -326,20 +328,22 @@ next_mark:
 // Lookup an extmark by id
 ExtmarkInfo extmark_from_id(buf_T *buf, uint32_t ns_id, uint32_t id)
 {
-  ExtmarkInfo ret = { 0, 0, -1, -1, -1, -1, DECORATION_INIT };
+  ExtmarkInfo ret = { 0, 0, -1, -1, -1, -1, false, false, DECORATION_INIT };
   mtkey_t mark = marktree_lookup_ns(buf->b_marktree, ns_id, id, false, NULL);
   if (!mark.id) {
     return ret;
   }
   assert(mark.pos.row >= 0);
-  mtpos_t endpos = marktree_get_altpos(buf->b_marktree, mark, NULL);
+  mtkey_t end = marktree_get_alt(buf->b_marktree, mark, NULL);
 
   ret.ns_id = ns_id;
   ret.mark_id = id;
   ret.row = mark.pos.row;
   ret.col = mark.pos.col;
-  ret.end_row = endpos.row;
-  ret.end_col = endpos.col;
+  ret.end_row = end.pos.row;
+  ret.end_col = end.pos.col;
+  ret.right_gravity = mt_right(mark);
+  ret.end_right_gravity = mt_right(end);
   ret.decor = get_decor(mark);
 
   return ret;
diff --git a/src/nvim/extmark.h b/src/nvim/extmark.h
index c6ec1d0aa8..af9526cd43 100644
--- a/src/nvim/extmark.h
+++ b/src/nvim/extmark.h
@@ -16,6 +16,8 @@ typedef struct {
   colnr_T col;
   int end_row;
   colnr_T end_col;
+  bool right_gravity;
+  bool end_right_gravity;
   Decoration decor;  // TODO(bfredl): CHONKY
 } ExtmarkInfo;
 
diff --git a/src/nvim/marktree.c b/src/nvim/marktree.c
index 8ae138b2eb..918db8b76c 100644
--- a/src/nvim/marktree.c
+++ b/src/nvim/marktree.c
@@ -1079,11 +1079,16 @@ found_node:
 
 mtpos_t marktree_get_altpos(MarkTree *b, mtkey_t mark, MarkTreeIter *itr)
 {
+  return marktree_get_alt(b, mark, itr).pos;
+}
+
+mtkey_t marktree_get_alt(MarkTree *b, mtkey_t mark, MarkTreeIter *itr)
+{
   mtkey_t end = MT_INVALID_KEY;
   if (mt_paired(mark)) {
     end = marktree_lookup_ns(b, mark.ns, mark.id, !mt_end(mark), itr);
   }
-  return end.pos;
+  return end;
 }
 
 static void marktree_itr_fix_pos(MarkTree *b, MarkTreeIter *itr)