More robust Buffer filesystem timestamp handling

src/buffer.cc

@@ -12,11 +12,13 @@
 namespace Kakoune
 {
 
-Buffer::Buffer(String name, Flags flags, std::vector<String> lines)
+Buffer::Buffer(String name, Flags flags, std::vector<String> lines,
+               time_t fs_timestamp)
     : m_name(std::move(name)), m_flags(flags | Flags::NoUndo),
       m_history(), m_history_cursor(m_history.begin()),
       m_last_save_undo_index(0),
       m_timestamp(0),
+      m_fs_timestamp(fs_timestamp),
       m_hooks(GlobalHooks::instance()),
       m_options(GlobalOptions::instance())
 {
@@ -44,7 +46,10 @@ Buffer::Buffer(String name, Flags flags, std::vector<String> lines)
         if (flags & Flags::New)
             m_hooks.run_hook("BufNew", m_name, context);
         else
+        {
+            kak_assert(m_fs_timestamp != InvalidTime);
             m_hooks.run_hook("BufOpen", m_name, context);
+        }
     }
 
     m_hooks.run_hook("BufCreate", m_name, context);
@@ -607,6 +612,7 @@ void Buffer::notify_saved()
         ++m_timestamp;
         m_last_save_undo_index = history_cursor_index;
     }
+    m_fs_timestamp = get_fs_timestamp(m_name);
 }
 
 BufferCoord Buffer::advance(BufferCoord coord, ByteCount count) const

src/buffer.hh

@@ -17,6 +17,8 @@ namespace Kakoune
 
 class Buffer;
 
+constexpr time_t InvalidTime = 0;
+
 struct BufferCoord : LineAndColumn<BufferCoord, LineCount, ByteCount>
 {
     constexpr BufferCoord(LineCount line = 0, ByteCount column = 0)
@@ -90,7 +92,8 @@ public:
         NoUndo = 8,
     };
 
-    Buffer(String name, Flags flags, std::vector<String> lines = { "\n" });
+    Buffer(String name, Flags flags, std::vector<String> lines = { "\n" },
+           time_t fs_timestamp = InvalidTime);
     Buffer(const Buffer&) = delete;
     Buffer& operator= (const Buffer&) = delete;
     ~Buffer();

src/commands.cc

@@ -147,9 +147,6 @@ void write_buffer(CommandParameters params, Context& context)
                                      : parse_filename(params[0]);
 
     write_buffer_to_file(buffer, filename);
-
-    if (filename == buffer.name())
-        buffer.notify_saved();
 }
 
 void write_all_buffers(CommandParameters params, Context& context)
@@ -160,10 +157,7 @@ void write_all_buffers(CommandParameters params, Context& context)
     for (auto& buffer : BufferManager::instance())
     {
         if ((buffer->flags() & Buffer::Flags::File) and buffer->is_modified())
-        {
             write_buffer_to_file(*buffer, buffer->name());
-            buffer->notify_saved();
-        }
     }
 }
 

src/file.cc

@@ -175,8 +175,8 @@ Buffer* create_buffer_from_file(String filename)
         else
             pos = line_end + 1;
     }
-    Buffer* buffer = new Buffer(filename, Buffer::Flags::File, std::move(lines));
+    Buffer* buffer = new Buffer{filename, Buffer::Flags::File,
-    buffer->set_fs_timestamp(st.st_mtime);
+                                std::move(lines), st.st_mtime};
 
     OptionManager& options = buffer->options();
     options.get_local_option("eolformat").set<String>(crlf ? "crlf" : "lf");
@@ -228,7 +228,7 @@ void write_buffer_to_file(Buffer& buffer, const String& filename)
         write(fd, eoldata, filename);
     }
     if ((buffer.flags() & Buffer::Flags::File) and filename == buffer.name())
-        buffer.set_fs_timestamp(get_fs_timestamp(filename));
+        buffer.notify_saved();
 }
 
 String find_file(const String& filename, memoryview<String> paths)
@@ -312,7 +312,7 @@ time_t get_fs_timestamp(const String& filename)
 {
     struct stat st;
     if (stat(filename.c_str(), &st) != 0)
-        throw runtime_error("stat failed on " + filename);
+        return InvalidTime;
     return st.st_mtime;
 }