From 5f37229c19c3a7387404444bb0d56a32669d4e6d Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Sat, 7 Jan 2017 16:22:28 -0500
Subject: [PATCH] when adjusting cursor iterators, always keep them valid

---
 src/core/Buffer.cc | 16 ++++++++++------
 src/core/Buffer.h  |  2 +-
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/core/Buffer.cc b/src/core/Buffer.cc
index 60ced06..7244cb3 100644
--- a/src/core/Buffer.cc
+++ b/src/core/Buffer.cc
@@ -168,23 +168,20 @@ void Buffer::exit_insert_mode()
     pop_operation();
 }
 
-void Buffer::insert_code_point(const Buffer::Iterator & position, uint32_t code_point, bool adjust_iterators)
+void Buffer::insert_code_point(const Buffer::Iterator & position, uint32_t code_point)
 {
     push_operation();
     Buffer::Iterator local_position = position;
     if ((code_point != '\n') && (size() == 0u))
     {
-        insert_code_point(position, '\n', false);
+        insert_code_point(position, '\n');
     }
     uint8_t encoded[Encoding::MAX_CODE_POINT_SIZE];
     uint8_t bytes = Encoding::encode(code_point, m_encoding, encoded);
     m_gap_buffer->insert(local_position.offset(), encoded, bytes);
     record_change(encoded, bytes, local_position.offset(), true);
     ssize_t lines = (code_point == '\n') ? 1 : 0;
-    if (adjust_iterators)
-    {
-        warp_iterators(local_position.offset(), bytes, lines, true);
-    }
+    warp_iterators(local_position.offset(), bytes, lines, true);
     pop_operation();
 }
 
@@ -217,6 +214,13 @@ void Buffer::warp_iterators(size_t offset, ssize_t offset_adjustment, ssize_t li
             iterator->warp(offset_adjustment, lines_adjustment);
         }
     }
+    for (auto cursor : m_cursors)
+    {
+        if ((*cursor == *m_eof_iterator) && (size() > 0u))
+        {
+            cursor->go_back();
+        }
+    }
 }
 
 void Buffer::pop_operation()
diff --git a/src/core/Buffer.h b/src/core/Buffer.h
index a242140..36e806a 100644
--- a/src/core/Buffer.h
+++ b/src/core/Buffer.h
@@ -119,7 +119,7 @@ public:
     void enter_insert_mode();
     void exit_insert_mode();
     bool insert_mode() const { return m_insert_mode; }
-    void insert_code_point(const Buffer::Iterator & position, uint32_t code_point, bool adjust_iterators = true);
+    void insert_code_point(const Buffer::Iterator & position, uint32_t code_point);
     void erase_code_point(const Buffer::Iterator & position);
     std::string filename() const { return m_filename; }
     Iterator begin() const { return Iterator(this); }