Store the timestamp at which a display buffer was generated

Coordinates inside a display buffer are only valid for a certain
buffer content, they cannot be used once the buffer has been
modified.

Fixes #2034

1 files changed, 4 insertions, 0 deletions

diff --git a/src/display_buffer.hh b/src/display_buffer.hh
index 6d20f105..ea945da1 100644
--- a/src/display_buffer.hh
+++ b/src/display_buffer.hh
@@ -163,9 +163,13 @@ public:
     // Optimize all lines, set DisplayLine::optimize
     void optimize();
 
+    void set_timestamp(size_t timestamp) { m_timestamp = timestamp; }
+    size_t timestamp() const { return m_timestamp; }
+
 private:
     LineList m_lines;
     BufferRange m_range;
+    size_t m_timestamp;
 };
 
 }