From 1e04489e5088fecb3e032f4681aa397282bdea02 Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Fri, 29 Dec 2017 18:02:06 -0800
Subject: [PATCH] Fix error in handling of padding in get_changed_ranges

---
 src/runtime/document.c           | 4 ++++
 src/runtime/get_changed_ranges.c | 6 ++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/runtime/document.c b/src/runtime/document.c
index 998b74bd..157fab9f 100644
--- a/src/runtime/document.c
+++ b/src/runtime/document.c
@@ -94,6 +94,10 @@ void ts_document_edit(TSDocument *self, TSInputEdit edit) {
     edit.bytes_removed = max_bytes - edit.start_byte;
 
   ts_tree_edit(self->tree, &edit);
+
+  if (self->parser.print_debugging_graphs) {
+    ts_tree_print_dot_graph(self->tree, self->parser.language, stderr);
+  }
 }
 
 void ts_document_parse(TSDocument *self) {
diff --git a/src/runtime/get_changed_ranges.c b/src/runtime/get_changed_ranges.c
index f275f13b..41fc1877 100644
--- a/src/runtime/get_changed_ranges.c
+++ b/src/runtime/get_changed_ranges.c
@@ -85,7 +85,8 @@ static void iterator_get_visible_state(const Iterator *self, Tree **tree,
   uint32_t i = self->path.size - 1;
 
   if (self->in_padding) {
-    while (self->path.contents[i].child_index == 0) i--;
+    if (i == 0) return;
+    i--;
   }
 
   for (; i + 1 > 0; i--) {
@@ -218,7 +219,8 @@ IteratorComparison iterator_compare(const Iterator *old_iter, const Iterator *ne
   iterator_get_visible_state(old_iter, &old_tree, &old_alias_symbol, &old_start);
   iterator_get_visible_state(new_iter, &new_tree, &new_alias_symbol, &new_start);
 
-  assert(old_tree && new_tree);
+  if (!old_tree && !new_tree) return IteratorMatches;
+  if (!old_tree || !new_tree) return IteratorDiffers;
 
   if (old_alias_symbol == new_alias_symbol) {
     if (old_start == new_start) {