From bfaf52f8c0ff6ab5e25944484be8014e855dd410 Mon Sep 17 00:00:00 2001
From: Maxime Coste <mawww@kakoune.org>
Date: Tue, 13 Mar 2018 14:00:57 +1100
Subject: [PATCH] Do not jump to buffer start on `g.` with no previous
 modifications

---
 src/buffer.cc | 2 +-
 src/buffer.hh | 5 +++--
 src/normal.cc | 6 ++++--
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/buffer.cc b/src/buffer.cc
index 7a4762647..f36944e4a 100644
--- a/src/buffer.cc
+++ b/src/buffer.cc
@@ -726,7 +726,7 @@ void Buffer::run_hook_in_own_context(StringView hook_name, StringView param, Str
     hooks().run_hook(hook_name, param, hook_handler.context());
 }
 
-BufferCoord Buffer::last_modification_coord() const
+Optional<BufferCoord> Buffer::last_modification_coord() const
 {
     if (m_history_cursor.get() == &m_history)
         return {};
diff --git a/src/buffer.hh b/src/buffer.hh
index d8f180158..7ff5bab7d 100644
--- a/src/buffer.hh
+++ b/src/buffer.hh
@@ -5,6 +5,7 @@
 #include "coord.hh"
 #include "constexpr_utils.hh"
 #include "enum.hh"
+#include "optional.hh"
 #include "safe_ptr.hh"
 #include "scope.hh"
 #include "shared_string.hh"
@@ -163,12 +164,12 @@ public:
     bool           is_valid(BufferCoord c) const;
     bool           is_end(BufferCoord c) const;
 
-    BufferCoord    last_modification_coord() const;
-
     BufferIterator begin() const;
     BufferIterator end() const;
     LineCount      line_count() const;
 
+    Optional<BufferCoord> last_modification_coord() const;
+
     StringView operator[](LineCount line) const
     { return m_lines[line]; }
 
diff --git a/src/normal.cc b/src/normal.cc
index 21609090c..aef3f79ac 100644
--- a/src/normal.cc
+++ b/src/normal.cc
@@ -306,9 +306,11 @@ void goto_commands(Context& context, NormalParams params)
             {
                 context.push_jump();
                 auto pos = buffer.last_modification_coord();
-                if (pos >= buffer.back_coord())
+                if (not pos)
+                    throw runtime_error("no last modification position");
+                if (*pos >= buffer.back_coord())
                     pos = buffer.back_coord();
-                select_coord<mode>(buffer, pos, context.selections());
+                select_coord<mode>(buffer, *pos, context.selections());
                 break;
             }
             }