diff --git a/builtin/common/settings/generate_from_settingtypes.lua b/builtin/common/settings/generate_from_settingtypes.lua
index 4c33a8fc1a..13b3035cef 100644
--- a/builtin/common/settings/generate_from_settingtypes.lua
+++ b/builtin/common/settings/generate_from_settingtypes.lua
@@ -102,7 +102,7 @@ end
 local translation_file_header = [[
 // This file is automatically generated
 // It contains a bunch of fake gettext calls, to tell xgettext about the strings in config files
-// To update it, refer to the bottom of builtin/mainmenu/dlg_settings_advanced.lua
+// To update it, refer to the bottom of builtin/common/settings/init.lua
 
 fake_function() {]]
 
@@ -110,15 +110,15 @@ local function create_translation_file(settings)
 	local result = { translation_file_header }
 	for _, entry in ipairs(settings) do
 		if entry.type == "category" then
-			insert(result, sprintf("\tgettext(%q);", entry.name))
+			insert(result, sprintf("\t/* xgettext:no-c-format */ gettext(%q);", entry.name))
 		else
 			if entry.readable_name then
-				insert(result, sprintf("\tgettext(%q);", entry.readable_name))
+				insert(result, sprintf("\t/* xgettext:no-c-format */ gettext(%q);", entry.readable_name))
 			end
 			if entry.comment ~= "" then
 				local comment_escaped = entry.comment:gsub("\n", "\\n")
 				comment_escaped = comment_escaped:gsub("\"", "\\\"")
-				insert(result, "\tgettext(\"" .. comment_escaped .. "\");")
+				insert(result, "\t/* xgettext:no-c-format */ gettext(\"" .. comment_escaped .. "\");")
 			end
 		end
 	end
diff --git a/doc/lua_api.md b/doc/lua_api.md
index 747c523a4d..3a6da1bdb8 100644
--- a/doc/lua_api.md
+++ b/doc/lua_api.md
@@ -5005,7 +5005,8 @@ A VoxelManip object can be created any time using either:
 If the optional position parameters are present for either of these routines,
 the specified region will be pre-loaded into the VoxelManip object on creation.
 Otherwise, the area of map you wish to manipulate must first be loaded into the
-VoxelManip object using `VoxelManip:read_from_map()`.
+VoxelManip object using `VoxelManip:read_from_map()`, or an empty one created
+with `VoxelManip:initialize()`.
 
 Note that `VoxelManip:read_from_map()` returns two position vectors. The region
 formed by these positions indicate the minimum and maximum (respectively)
@@ -5016,14 +5017,14 @@ be queried any time after loading map data with `VoxelManip:get_emerged_area()`.
 Now that the VoxelManip object is populated with map data, your mod can fetch a
 copy of this data using either of two methods. `VoxelManip:get_node_at()`,
 which retrieves an individual node in a MapNode formatted table at the position
-requested is the simplest method to use, but also the slowest.
+requested. This is the simplest method to use, but also the slowest.
 
 Nodes in a VoxelManip object may also be read in bulk to a flat array table
 using:
 
 * `VoxelManip:get_data()` for node content (in Content ID form, see section
   [Content IDs]),
-* `VoxelManip:get_light_data()` for node light levels, and
+* `VoxelManip:get_light_data()` for node param (usually light levels), and
 * `VoxelManip:get_param2_data()` for the node type-dependent "param2" values.
 
 See section [Flat array format] for more details.
@@ -5038,17 +5039,16 @@ internal state unless otherwise explicitly stated.
 Once the bulk data has been edited to your liking, the internal VoxelManip
 state can be set using:
 
-* `VoxelManip:set_data()` for node content (in Content ID form, see section
-  [Content IDs]),
-* `VoxelManip:set_light_data()` for node light levels, and
-* `VoxelManip:set_param2_data()` for the node type-dependent `param2` values.
+* `VoxelManip:set_data()` or
+* `VoxelManip:set_light_data()` or
+* `VoxelManip:set_param2_data()`
 
 The parameter to each of the above three functions can use any table at all in
 the same flat array format as produced by `get_data()` etc. and is not required
 to be a table retrieved from `get_data()`.
 
 Once the internal VoxelManip state has been modified to your liking, the
-changes can be committed back to the map by calling `VoxelManip:write_to_map()`
+changes can be committed back to the map by calling `VoxelManip:write_to_map()`.
 
 ### Flat array format
 
@@ -5180,15 +5180,22 @@ inside the VoxelManip.
 Methods
 -------
 
-* `read_from_map(p1, p2)`: Loads a chunk of map into the VoxelManip object
+* `read_from_map(p1, p2)`: Loads a part of the map into the VoxelManip object
   containing the region formed by `p1` and `p2`.
-    * returns actual emerged `pmin`, actual emerged `pmax`
+    * returns actual emerged `pmin`, actual emerged `pmax` (MapBlock-aligned)
     * Note that calling this multiple times will *add* to the area loaded in the
       VoxelManip, and not reset it.
+* `initialize(p1, p2, [node])`: Clears and resizes the VoxelManip object to
+  comprise the region formed by `p1` and `p2`.
+   * **No data** is read from the map, so you can use this to treat `VoxelManip`
+     objects as general containers of node data.
+   * `node`: if present the data will be filled with this node; if not it will
+     be uninitialized
+   * returns actual emerged `pmin`, actual emerged `pmax` (MapBlock-aligned)
+   * (introduced in 5.13.0)
 * `write_to_map([light])`: Writes the data loaded from the `VoxelManip` back to
   the map.
-    * **important**: data must be set using `VoxelManip:set_data()` before
-      calling this.
+    * **important**: you should call `set_data()` before this, or nothing will change.
     * if `light` is true, then lighting is automatically recalculated.
       The default value is true.
       If `light` is false, no light calculations happen, and you should correct
@@ -5249,6 +5256,15 @@ Methods
    where the engine will keep the map and the VM in sync automatically.
    * Note: this doesn't do what you think it does and is subject to removal. Don't use it!
 * `get_emerged_area()`: Returns actual emerged minimum and maximum positions.
+   * "Emerged" does not imply that this region was actually loaded from the map,
+      if `initialize()` has been used.
+* `close()`: Frees the data buffers associated with the VoxelManip object.
+   It will become empty.
+   * Since Lua's garbage collector is not aware of the potentially significant
+     memory behind a VoxelManip, frequent VoxelManip usage can cause the server to
+     run out of RAM. Therefore it's recommend to call this method once you're done
+     with the VoxelManip.
+   * (introduced in 5.13.0)
 
 `VoxelArea`
 -----------
diff --git a/doc/menu_lua_api.md b/doc/menu_lua_api.md
index 0a067764e9..56b51f3b9f 100644
--- a/doc/menu_lua_api.md
+++ b/doc/menu_lua_api.md
@@ -23,8 +23,8 @@ Callbacks
 * `core.button_handler(fields)`: called when a button is pressed.
   * `fields` = `{name1 = value1, name2 = value2, ...}`
 * `core.event_handler(event)`
-  * `event`: `"MenuQuit"`, `"KeyEnter"`, `"ExitButton"`, `"EditBoxEnter"` or
-    `"FullscreenChange"`
+  * `event`: `"MenuQuit"` (derived from `quit`) or `"FullscreenChange"`
+    The main menu may issue custom events, such as `"Refresh"` (server list).
 * `core.on_before_close()`: called before the menu is closed, either to exit or
   to join a game
 
diff --git a/src/client/game_formspec.cpp b/src/client/game_formspec.cpp
index dc51247b0e..3d8dc6fc8d 100644
--- a/src/client/game_formspec.cpp
+++ b/src/client/game_formspec.cpp
@@ -31,16 +31,6 @@ struct TextDestNodeMetadata : public TextDest
 		m_p = p;
 		m_client = client;
 	}
-	// This is deprecated I guess? -celeron55
-	void gotText(const std::wstring &text)
-	{
-		std::string ntext = wide_to_utf8(text);
-		infostream << "Submitting 'text' field of node at (" << m_p.X << ","
-			   << m_p.Y << "," << m_p.Z << "): " << ntext << std::endl;
-		StringMap fields;
-		fields["text"] = ntext;
-		m_client->sendNodemetaFields(m_p, "", fields);
-	}
 	void gotText(const StringMap &fields)
 	{
 		m_client->sendNodemetaFields(m_p, "", fields);
diff --git a/src/dummymap.h b/src/dummymap.h
index 2da3718848..408f91341d 100644
--- a/src/dummymap.h
+++ b/src/dummymap.h
@@ -27,12 +27,13 @@ public:
 	void fill(v3s16 bpmin, v3s16 bpmax, MapNode n)
 	{
 		for (s16 z = bpmin.Z; z <= bpmax.Z; z++)
-		for (s16 y = bpmin.Y; y <= bpmax.Y; y++)
-		for (s16 x = bpmin.X; x <= bpmax.X; x++) {
+		for (s16 x = bpmin.X; x <= bpmax.X; x++)
+		for (s16 y = bpmin.Y; y <= bpmax.Y; y++) {
 			MapBlock *block = getBlockNoCreateNoEx({x, y, z});
 			if (block) {
+				auto *data = block->getData();
 				for (size_t i = 0; i < MapBlock::nodecount; i++)
-					block->getData()[i] = n;
+					data[i] = n;
 				block->expireIsAirCache();
 			}
 		}
diff --git a/src/gui/guiEngine.cpp b/src/gui/guiEngine.cpp
index b31f12ef9a..0ec0d7a764 100644
--- a/src/gui/guiEngine.cpp
+++ b/src/gui/guiEngine.cpp
@@ -40,12 +40,6 @@ void TextDestGuiEngine::gotText(const StringMap &fields)
 	m_engine->getScriptIface()->handleMainMenuButtons(fields);
 }
 
-/******************************************************************************/
-void TextDestGuiEngine::gotText(const std::wstring &text)
-{
-	m_engine->getScriptIface()->handleMainMenuEvent(wide_to_utf8(text));
-}
-
 /******************************************************************************/
 MenuTextureSource::~MenuTextureSource()
 {
diff --git a/src/gui/guiEngine.h b/src/gui/guiEngine.h
index 5c95e9a4c2..f4b22f3c26 100644
--- a/src/gui/guiEngine.h
+++ b/src/gui/guiEngine.h
@@ -61,12 +61,6 @@ public:
 	 */
 	void gotText(const StringMap &fields);
 
-	/**
-	 * receive text/events transmitted by guiFormSpecMenu
-	 * @param text textual representation of event
-	 */
-	void gotText(const std::wstring &text);
-
 private:
 	/** target to transmit data to */
 	GUIEngine *m_engine = nullptr;
diff --git a/src/gui/guiFormSpecMenu.cpp b/src/gui/guiFormSpecMenu.cpp
index f1e91bd0b8..97d86b05f8 100644
--- a/src/gui/guiFormSpecMenu.cpp
+++ b/src/gui/guiFormSpecMenu.cpp
@@ -77,6 +77,9 @@
 		return; \
 	}
 
+// Element ID of the "Proceed" button shown for sizeless formspecs
+constexpr s32 ID_PROCEED_BTN = 257;
+
 /*
 	GUIFormSpecMenu
 */
@@ -2998,7 +3001,7 @@ void GUIFormSpecMenu::regenerateGui(v2u32 screensize)
 		gui::IGUIElement *focused_element = Environment->getFocus();
 		if (focused_element && focused_element->getParent() == this) {
 			s32 focused_id = focused_element->getID();
-			if (focused_id > 257) {
+			if (focused_id > ID_PROCEED_BTN) {
 				for (const GUIFormSpecMenu::FieldSpec &field : m_fields) {
 					if (field.fid == focused_id) {
 						m_focused_element = field.fname;
@@ -3308,7 +3311,7 @@ void GUIFormSpecMenu::regenerateGui(v2u32 screensize)
 					size.X / 2 - 70,       pos.Y,
 					size.X / 2 - 70 + 140, pos.Y + m_btn_height * 2
 			);
-			GUIButton::addButton(Environment, mydata.rect, m_tsrc, this, 257,
+			GUIButton::addButton(Environment, mydata.rect, m_tsrc, this, ID_PROCEED_BTN,
 					wstrgettext("Proceed").c_str());
 		}
 	}
@@ -4031,12 +4034,7 @@ bool GUIFormSpecMenu::preprocessEvent(const SEvent& event)
 			if (m_joystick->wasKeyDown(KeyType::ESC)) {
 				tryClose();
 			} else if (m_joystick->wasKeyDown(KeyType::JUMP)) {
-				if (m_allowclose) {
-					acceptInput(quit_mode_accept);
-					quitMenu();
-				} else {
-					acceptInput(quit_mode_try);
-				}
+				trySubmitClose();
 			}
 		}
 		return handled;
@@ -4056,6 +4054,16 @@ void GUIFormSpecMenu::tryClose()
 	}
 }
 
+void GUIFormSpecMenu::trySubmitClose()
+{
+	if (m_allowclose) {
+		acceptInput(quit_mode_accept);
+		quitMenu();
+	} else {
+		acceptInput(quit_mode_try);
+	}
+}
+
 bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 {
 	if (event.EventType==EET_KEY_INPUT_EVENT) {
@@ -4099,12 +4107,7 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 					break;
 			}
 			if (current_keys_pending.key_enter) {
-				if (m_allowclose) {
-					acceptInput(quit_mode_accept);
-					quitMenu();
-				} else {
-					acceptInput(quit_mode_try);
-				}
+				trySubmitClose();
 			} else {
 				acceptInput();
 			}
@@ -4818,12 +4821,18 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 	}
 
 	if (event.EventType == EET_GUI_EVENT) {
-		if (event.GUIEvent.EventType == gui::EGET_TAB_CHANGED
-				&& isVisible()) {
-			// find the element that was clicked
+		const s32 caller_id = event.GUIEvent.Caller->getID();
+		bool close_on_enter;
+
+		switch (event.GUIEvent.EventType) {
+		case gui::EGET_TAB_CHANGED:
+			if (!isVisible())
+				break;
+
+				// find the element that was clicked
 			for (GUIFormSpecMenu::FieldSpec &s : m_fields) {
-				if ((s.ftype == f_TabHeader) &&
-						(s.fid == event.GUIEvent.Caller->getID())) {
+				if (s.ftype == f_TabHeader &&
+						s.fid == caller_id) {
 					if (!s.sound.empty() && m_sound_manager)
 						m_sound_manager->playSound(0, SoundSpec(s.sound, 1.0f));
 					s.send = true;
@@ -4832,26 +4841,26 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 					return true;
 				}
 			}
-		}
-		if (event.GUIEvent.EventType == gui::EGET_ELEMENT_FOCUS_LOST
-				&& isVisible()) {
+			break;
+
+		case gui::EGET_ELEMENT_FOCUS_LOST:
+			if (!isVisible())
+				break;
+
 			if (!canTakeFocus(event.GUIEvent.Element)) {
 				infostream<<"GUIFormSpecMenu: Not allowing focus change."
 						<<std::endl;
 				// Returning true disables focus change
 				return true;
 			}
-		}
-		if ((event.GUIEvent.EventType == gui::EGET_BUTTON_CLICKED) ||
-				(event.GUIEvent.EventType == gui::EGET_CHECKBOX_CHANGED) ||
-				(event.GUIEvent.EventType == gui::EGET_COMBO_BOX_CHANGED) ||
-				(event.GUIEvent.EventType == gui::EGET_SCROLL_BAR_CHANGED)) {
-			s32 caller_id = event.GUIEvent.Caller->getID();
+			break;
 
-			if (caller_id == 257) {
-				acceptInput(quit_mode_accept);
-				m_text_dst->gotText(L"ExitButton");
-				quitMenu();
+		case gui::EGET_BUTTON_CLICKED:
+		case gui::EGET_CHECKBOX_CHANGED:
+		case gui::EGET_COMBO_BOX_CHANGED:
+		case gui::EGET_SCROLL_BAR_CHANGED:
+			if (caller_id == ID_PROCEED_BTN) {
+				trySubmitClose();
 				return true;
 			}
 
@@ -4881,7 +4890,6 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 
 					if (s.is_exit) {
 						acceptInput(quit_mode_accept);
-						m_text_dst->gotText(L"ExitButton");
 						quitMenu();
 						return true;
 					}
@@ -4922,60 +4930,57 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 					s.send = false;
 				}
 			}
-		}
 
-		if (event.GUIEvent.EventType == gui::EGET_SCROLL_BAR_CHANGED) {
-			// move scroll_containers
-			for (const std::pair<std::string, GUIScrollContainer *> &c : m_scroll_containers)
-				c.second->onScrollEvent(event.GUIEvent.Caller);
-		}
+			if (event.GUIEvent.EventType == gui::EGET_SCROLL_BAR_CHANGED) {
+				// move scroll_containers
+				for (const std::pair<std::string, GUIScrollContainer *> &c : m_scroll_containers)
+					c.second->onScrollEvent(event.GUIEvent.Caller);
+			}
+			break;
 
-		if (event.GUIEvent.EventType == gui::EGET_EDITBOX_ENTER) {
-			if (event.GUIEvent.Caller->getID() > 257) {
-				bool close_on_enter = true;
-				for (GUIFormSpecMenu::FieldSpec &s : m_fields) {
-					if (s.ftype == f_Unknown &&
-							s.fid == event.GUIEvent.Caller->getID()) {
-						current_field_enter_pending = s.fname;
-						auto it = field_close_on_enter.find(s.fname);
-						if (it != field_close_on_enter.end())
-							close_on_enter = (*it).second;
+		case gui::EGET_EDITBOX_ENTER:
+			if (caller_id <= ID_PROCEED_BTN)
+				break;
 
-						break;
-					}
+			close_on_enter = true;
+			for (GUIFormSpecMenu::FieldSpec &s : m_fields) {
+				if (s.ftype == f_Unknown &&
+						s.fid == caller_id) {
+					current_field_enter_pending = s.fname;
+					auto it = field_close_on_enter.find(s.fname);
+					if (it != field_close_on_enter.end())
+						close_on_enter = (*it).second;
+
+					break;
 				}
+			}
 
-				current_keys_pending.key_enter = true;
+			current_keys_pending.key_enter = true;
 
-				if (close_on_enter) {
-					if (m_allowclose) {
-						acceptInput(quit_mode_accept);
-						quitMenu();
-					} else {
-						acceptInput(quit_mode_try);
-					}
-				} else {
+			if (close_on_enter)
+				trySubmitClose();
+			else
+				acceptInput();
+			return true;
+
+		case gui::EGET_TABLE_CHANGED:
+			if (caller_id <= ID_PROCEED_BTN)
+				break;
+
+			// find the element that was clicked
+			for (GUIFormSpecMenu::FieldSpec &s : m_fields) {
+				// if it's a table, set the send field
+				// so lua knows which table was changed
+				if (s.ftype == f_Table && s.fid == caller_id) {
+					s.send = true;
 					acceptInput();
+					s.send = false;
 				}
-				return true;
 			}
-		}
+			return true;
 
-		if (event.GUIEvent.EventType == gui::EGET_TABLE_CHANGED) {
-			int current_id = event.GUIEvent.Caller->getID();
-			if (current_id > 257) {
-				// find the element that was clicked
-				for (GUIFormSpecMenu::FieldSpec &s : m_fields) {
-					// if it's a table, set the send field
-					// so lua knows which table was changed
-					if ((s.ftype == f_Table) && (s.fid == current_id)) {
-						s.send = true;
-						acceptInput();
-						s.send=false;
-					}
-				}
-				return true;
-			}
+		default:
+			break;
 		}
 	}
 
diff --git a/src/gui/guiFormSpecMenu.h b/src/gui/guiFormSpecMenu.h
index 8dbfcab93f..f279bbb298 100644
--- a/src/gui/guiFormSpecMenu.h
+++ b/src/gui/guiFormSpecMenu.h
@@ -68,8 +68,6 @@ struct TextDest
 {
 	virtual ~TextDest() = default;
 
-	// This is deprecated I guess? -celeron55
-	virtual void gotText(const std::wstring &text) {}
 	virtual void gotText(const StringMap &fields) = 0;
 
 	std::string m_formname;
@@ -493,6 +491,7 @@ private:
 	bool parseMiddleRect(const std::string &value, core::rect<s32> *parsed_rect);
 
 	void tryClose();
+	void trySubmitClose();
 
 	void showTooltip(const std::wstring &text, const irr::video::SColor &color,
 		const irr::video::SColor &bgcolor);
diff --git a/src/map.cpp b/src/map.cpp
index d882008465..964d8b5afa 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -772,52 +772,79 @@ void MMVManip::initialEmerge(v3s16 p_min, v3s16 p_max, bool load_if_inexistent)
 		infostream<<std::endl;
 	}
 
-	const bool all_new = m_area.hasEmptyExtent() || block_area_nodes.contains(m_area);
+	std::map<v3s16, bool> had_blocks;
+	// we can skip this calculation if the areas are disjoint
+	if (!m_area.intersect(block_area_nodes).hasEmptyExtent())
+		had_blocks = getCoveredBlocks();
+
+	const bool all_new = m_area.hasEmptyExtent();
 	addArea(block_area_nodes);
 
 	for(s32 z=p_min.Z; z<=p_max.Z; z++)
 	for(s32 y=p_min.Y; y<=p_max.Y; y++)
 	for(s32 x=p_min.X; x<=p_max.X; x++)
 	{
-		u8 flags = 0;
-		MapBlock *block;
 		v3s16 p(x,y,z);
-		if (m_loaded_blocks.count(p) > 0)
+		// if this block was already in the vmanip and it has data, skip
+		if (auto it = had_blocks.find(p); it != had_blocks.end() && it->second)
 			continue;
 
-		bool block_data_inexistent = false;
-		{
-			TimeTaker timer2("emerge load", &emerge_load_time);
-
-			block = m_map->getBlockNoCreateNoEx(p);
-			if (!block)
-				block_data_inexistent = true;
-			else
-				block->copyTo(*this);
-		}
-
-		if(block_data_inexistent)
-		{
-
+		MapBlock *block = m_map->getBlockNoCreateNoEx(p);
+		if (block) {
+			block->copyTo(*this);
+		} else {
 			if (load_if_inexistent && !blockpos_over_max_limit(p)) {
 				block = m_map->emergeBlock(p, true);
+				assert(block);
 				block->copyTo(*this);
 			} else {
-				flags |= VMANIP_BLOCK_DATA_INEXIST;
-
 				// Mark area inexistent
 				VoxelArea a(p*MAP_BLOCKSIZE, (p+1)*MAP_BLOCKSIZE-v3s16(1,1,1));
 				setFlags(a, VOXELFLAG_NO_DATA);
 			}
 		}
-
-		m_loaded_blocks[p] = flags;
 	}
 
 	if (all_new)
 		m_is_dirty = false;
 }
 
+std::map<v3s16, bool> MMVManip::getCoveredBlocks() const
+{
+	std::map<v3s16, bool> ret;
+	if (m_area.hasEmptyExtent())
+		return ret;
+
+	// Figure out if *any* node in this block has data according to m_flags
+	const auto &check_block = [this] (v3s16 bp) -> bool {
+		v3s16 pmin = bp * MAP_BLOCKSIZE;
+		v3s16 pmax = pmin + v3s16(MAP_BLOCKSIZE-1);
+		for(s16 z=pmin.Z; z<=pmax.Z; z++)
+		for(s16 y=pmin.Y; y<=pmax.Y; y++)
+		for(s16 x=pmin.X; x<=pmax.X; x++) {
+			if (!(m_flags[m_area.index(x,y,z)] & VOXELFLAG_NO_DATA))
+				return true;
+		}
+		return false;
+	};
+
+	v3s16 bpmin = getNodeBlockPos(m_area.MinEdge);
+	v3s16 bpmax = getNodeBlockPos(m_area.MaxEdge);
+
+	if (bpmin * MAP_BLOCKSIZE != m_area.MinEdge)
+		throw BaseException("MMVManip not block-aligned");
+	if ((bpmax+1) * MAP_BLOCKSIZE - v3s16(1) != m_area.MaxEdge)
+		throw BaseException("MMVManip not block-aligned");
+
+	for(s16 z=bpmin.Z; z<=bpmax.Z; z++)
+	for(s16 y=bpmin.Y; y<=bpmax.Y; y++)
+	for(s16 x=bpmin.X; x<=bpmax.X; x++) {
+		v3s16 bp(x,y,z);
+		ret[bp] = check_block(bp);
+	}
+	return ret;
+}
+
 void MMVManip::blitBackAll(std::map<v3s16, MapBlock*> *modified_blocks,
 	bool overwrite_generated) const
 {
@@ -825,16 +852,27 @@ void MMVManip::blitBackAll(std::map<v3s16, MapBlock*> *modified_blocks,
 		return;
 	assert(m_map);
 
-	/*
-		Copy data of all blocks
-	*/
-	assert(!m_loaded_blocks.empty());
-	for (auto &loaded_block : m_loaded_blocks) {
-		v3s16 p = loaded_block.first;
+	size_t nload = 0;
+
+	// Copy all the blocks with data back to the map
+	const auto loaded_blocks = getCoveredBlocks();
+	for (auto &it : loaded_blocks) {
+		if (!it.second)
+			continue;
+		v3s16 p = it.first;
 		MapBlock *block = m_map->getBlockNoCreateNoEx(p);
-		bool existed = !(loaded_block.second & VMANIP_BLOCK_DATA_INEXIST);
-		if (!existed || (block == NULL) ||
-			(!overwrite_generated && block->isGenerated()))
+		if (!block) {
+			if (!blockpos_over_max_limit(p)) {
+				block = m_map->emergeBlock(p, true);
+				nload++;
+			}
+		}
+		if (!block) {
+			warningstream << "blitBackAll: Couldn't load block " << p
+				<< " to write data to map" << std::endl;
+			continue;
+		}
+		if (!overwrite_generated && block->isGenerated())
 			continue;
 
 		block->copyFrom(*this);
@@ -844,6 +882,10 @@ void MMVManip::blitBackAll(std::map<v3s16, MapBlock*> *modified_blocks,
 		if(modified_blocks)
 			(*modified_blocks)[p] = block;
 	}
+
+	if (nload > 0) {
+		verbosestream << "blitBackAll: " << nload << " blocks had to be loaded for writing" << std::endl;
+	}
 }
 
 MMVManip *MMVManip::clone() const
@@ -860,11 +902,7 @@ MMVManip *MMVManip::clone() const
 		ret->m_flags = new u8[size];
 		memcpy(ret->m_flags, m_flags, size * sizeof(u8));
 	}
-
 	ret->m_is_dirty = m_is_dirty;
-	// Even if the copy is disconnected from a map object keep the information
-	// needed to write it back to one
-	ret->m_loaded_blocks = m_loaded_blocks;
 
 	return ret;
 }
diff --git a/src/map.h b/src/map.h
index 9ec66cfb93..57ede8ee68 100644
--- a/src/map.h
+++ b/src/map.h
@@ -307,16 +307,29 @@ public:
 	MMVManip(Map *map);
 	virtual ~MMVManip() = default;
 
-	virtual void clear()
-	{
-		VoxelManipulator::clear();
-		m_loaded_blocks.clear();
-	}
-
+	/*
+		Loads specified area from map and *adds* it to the area already
+		contained in the VManip.
+	*/
 	void initialEmerge(v3s16 blockpos_min, v3s16 blockpos_max,
 		bool load_if_inexistent = true);
 
-	// This is much faster with big chunks of generated data
+	/**
+		Uses the flags array to determine which blocks the VManip covers,
+		and for which of them we have any data.
+		@warning requires VManip area to be block-aligned
+		@return map of blockpos -> any data?
+	*/
+	std::map<v3s16, bool> getCoveredBlocks() const;
+
+	/**
+		Writes data in VManip back to the map. Blocks without any data in the VManip
+		are skipped.
+		@note VOXELFLAG_NO_DATA is checked per-block, not per-node. So you need
+		to ensure that the relevant parts of m_data are initialized.
+		@param modified_blocks output array of touched blocks (optional)
+		@param overwrite_generated if false, blocks marked as generate in the map are not changed
+	*/
 	void blitBackAll(std::map<v3s16, MapBlock*> * modified_blocks,
 		bool overwrite_generated = true) const;
 
@@ -339,13 +352,4 @@ protected:
 
 	// may be null
 	Map *m_map = nullptr;
-	/*
-		key = blockpos
-		value = flags describing the block
-	*/
-	std::map<v3s16, u8> m_loaded_blocks;
-
-	enum : u8 {
-		VMANIP_BLOCK_DATA_INEXIST = 1 << 0,
-	};
 };
diff --git a/src/network/serverpackethandler.cpp b/src/network/serverpackethandler.cpp
index d9a38e8787..e9012d3519 100644
--- a/src/network/serverpackethandler.cpp
+++ b/src/network/serverpackethandler.cpp
@@ -40,10 +40,6 @@ void Server::handleCommand_Deprecated(NetworkPacket* pkt)
 
 void Server::handleCommand_Init(NetworkPacket* pkt)
 {
-
-	if(pkt->getSize() < 1)
-		return;
-
 	session_t peer_id = pkt->getPeerId();
 	RemoteClient *client = getClient(peer_id, CS_Created);
 
@@ -75,15 +71,6 @@ void Server::handleCommand_Init(NetworkPacket* pkt)
 	verbosestream << "Server: Got TOSERVER_INIT from " << addr_s <<
 		" (peer_id=" << peer_id << ")" << std::endl;
 
-	// Do not allow multiple players in simple singleplayer mode.
-	// This isn't a perfect way to do it, but will suffice for now
-	if (m_simple_singleplayer_mode && !m_clients.getClientIDs().empty()) {
-		infostream << "Server: Not allowing another client (" << addr_s <<
-			") to connect in simple singleplayer mode" << std::endl;
-		DenyAccess(peer_id, SERVER_ACCESSDENIED_SINGLEPLAYER);
-		return;
-	}
-
 	if (denyIfBanned(peer_id))
 		return;
 
@@ -161,18 +148,14 @@ void Server::handleCommand_Init(NetworkPacket* pkt)
 		return;
 	}
 
-	RemotePlayer *player = m_env->getPlayer(playername, true);
-
-	// If player is already connected, cancel
-	if (player && player->getPeerId() != PEER_ID_INEXISTENT) {
-		actionstream << "Server: Player with name \"" << playername <<
-			"\" tried to connect, but player with same name is already connected" << std::endl;
-		DenyAccess(peer_id, SERVER_ACCESSDENIED_ALREADY_CONNECTED);
+	// Do not allow multiple players in simple singleplayer mode
+	if (isSingleplayer() && !m_clients.getClientIDs(CS_HelloSent).empty()) {
+		infostream << "Server: Not allowing another client (" << addr_s <<
+			") to connect in simple singleplayer mode" << std::endl;
+		DenyAccess(peer_id, SERVER_ACCESSDENIED_SINGLEPLAYER);
 		return;
 	}
-
-	m_clients.setPlayerName(peer_id, playername);
-
+	// Or the "singleplayer" name to be used on regular servers
 	if (!isSingleplayer() && strcasecmp(playername, "singleplayer") == 0) {
 		actionstream << "Server: Player with the name \"singleplayer\" tried "
 			"to connect from " << addr_s << std::endl;
@@ -180,12 +163,25 @@ void Server::handleCommand_Init(NetworkPacket* pkt)
 		return;
 	}
 
+	{
+		RemotePlayer *player = m_env->getPlayer(playername, true);
+		// If player is already connected, cancel
+		if (player && player->getPeerId() != PEER_ID_INEXISTENT) {
+			actionstream << "Server: Player with name \"" << playername <<
+				"\" tried to connect, but player with same name is already connected" << std::endl;
+			DenyAccess(peer_id, SERVER_ACCESSDENIED_ALREADY_CONNECTED);
+			return;
+		}
+	}
+
+	client->setName(playerName);
+
 	{
 		std::string reason;
 		if (m_script->on_prejoinplayer(playername, addr_s, &reason)) {
 			actionstream << "Server: Player with the name \"" << playerName <<
 				"\" tried to connect from " << addr_s <<
-				" but it was disallowed for the following reason: " << reason <<
+				" but was disallowed for the following reason: " << reason <<
 				std::endl;
 			DenyAccess(peer_id, SERVER_ACCESSDENIED_CUSTOM_STRING, reason);
 			return;
@@ -195,14 +191,11 @@ void Server::handleCommand_Init(NetworkPacket* pkt)
 	infostream << "Server: New connection: \"" << playerName << "\" from " <<
 		addr_s << " (peer_id=" << peer_id << ")" << std::endl;
 
-	// Enforce user limit.
-	// Don't enforce for users that have some admin right or mod permits it.
-	if (m_clients.isUserLimitReached() &&
-			playername != g_settings->get("name") &&
-			!m_script->can_bypass_userlimit(playername, addr_s)) {
+	// Early check for user limit, so the client doesn't need to run
+	// through the join process only to be denied.
+	if (checkUserLimit(playerName, addr_s)) {
 		actionstream << "Server: " << playername << " tried to join from " <<
-			addr_s << ", but there are already max_users=" <<
-			g_settings->getU16("max_users") << " players." << std::endl;
+			addr_s << ", but the user limit was reached." << std::endl;
 		DenyAccess(peer_id, SERVER_ACCESSDENIED_TOO_MANY_USERS);
 		return;
 	}
@@ -302,6 +295,7 @@ void Server::handleCommand_Init2(NetworkPacket* pkt)
 	sendMediaAnnouncement(peer_id, lang);
 
 	RemoteClient *client = getClient(peer_id, CS_InitDone);
+	assert(client);
 
 	// Keep client language for server translations
 	client->setLangCode(lang);
@@ -354,6 +348,8 @@ void Server::handleCommand_RequestMedia(NetworkPacket* pkt)
 void Server::handleCommand_ClientReady(NetworkPacket* pkt)
 {
 	session_t peer_id = pkt->getPeerId();
+	RemoteClient *client = getClient(peer_id, CS_Created);
+	assert(client);
 
 	// decode all information first
 	u8 major_ver, minor_ver, patch_ver, reserved;
@@ -364,8 +360,17 @@ void Server::handleCommand_ClientReady(NetworkPacket* pkt)
 	if (pkt->getRemainingBytes() >= 2)
 		*pkt >> formspec_ver;
 
-	m_clients.setClientVersion(peer_id, major_ver, minor_ver, patch_ver,
-		full_ver);
+	client->setVersionInfo(major_ver, minor_ver, patch_ver, full_ver);
+
+	// Since only active clients count for the user limit, two could race the
+	// join process so we have to do a final check for the user limit here.
+	std::string addr_s = client->getAddress().serializeString();
+	if (checkUserLimit(client->getName(), addr_s)) {
+		actionstream << "Server: " << client->getName() << " tried to join from " <<
+			addr_s << ", but the user limit was reached (late)." << std::endl;
+		DenyAccess(peer_id, SERVER_ACCESSDENIED_TOO_MANY_USERS);
+		return;
+	}
 
 	// Emerge player
 	PlayerSAO* playersao = StageTwoClientInit(peer_id);
@@ -1426,7 +1431,7 @@ void Server::handleCommand_FirstSrp(NetworkPacket* pkt)
 
 	std::string salt, verification_key;
 
-	std::string addr_s = getPeerAddress(peer_id).serializeString();
+	std::string addr_s = client->getAddress().serializeString();
 	u8 is_empty;
 
 	*pkt >> salt >> verification_key >> is_empty;
@@ -1512,9 +1517,11 @@ void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
 	RemoteClient *client = getClient(peer_id, CS_Invalid);
 	ClientState cstate = client->getState();
 
+	std::string addr_s = client->getAddress().serializeString();
+
 	if (!((cstate == CS_HelloSent) || (cstate == CS_Active))) {
 		actionstream << "Server: got SRP _A packet in wrong state " << cstate <<
-			" from " << getPeerAddress(peer_id).serializeString() <<
+			" from " << addr_s <<
 			". Ignoring." << std::endl;
 		return;
 	}
@@ -1524,7 +1531,7 @@ void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
 	if (client->chosen_mech != AUTH_MECHANISM_NONE) {
 		actionstream << "Server: got SRP _A packet, while auth is already "
 			"going on with mech " << client->chosen_mech << " from " <<
-			getPeerAddress(peer_id).serializeString() <<
+			addr_s <<
 			" (wantSudo=" << wantSudo << "). Ignoring." << std::endl;
 		if (wantSudo) {
 			DenySudoAccess(peer_id);
@@ -1541,7 +1548,7 @@ void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
 
 	infostream << "Server: TOSERVER_SRP_BYTES_A received with "
 		<< "based_on=" << int(based_on) << " and len_A="
-		<< bytes_A.length() << "." << std::endl;
+		<< bytes_A.length() << std::endl;
 
 	AuthMechanism chosen = (based_on == 0) ?
 		AUTH_MECHANISM_LEGACY_PASSWORD : AUTH_MECHANISM_SRP;
@@ -1550,17 +1557,17 @@ void Server::handleCommand_SrpBytesA(NetworkPacket* pkt)
 		// Right now, the auth mechs don't change between login and sudo mode.
 		if (!client->isMechAllowed(chosen)) {
 			actionstream << "Server: Player \"" << client->getName() <<
-				"\" at " << getPeerAddress(peer_id).serializeString() <<
+				"\" from " << addr_s <<
 				" tried to change password using unallowed mech " << chosen <<
-				"." << std::endl;
+				std::endl;
 			DenySudoAccess(peer_id);
 			return;
 		}
 	} else {
 		if (!client->isMechAllowed(chosen)) {
 			actionstream << "Server: Client tried to authenticate from " <<
-				getPeerAddress(peer_id).serializeString() <<
-				" using unallowed mech " << chosen << "." << std::endl;
+				addr_s <<
+				" using unallowed mech " << chosen << std::endl;
 			DenyAccess(peer_id, SERVER_ACCESSDENIED_UNEXPECTED_DATA);
 			return;
 		}
diff --git a/src/script/lua_api/l_server.cpp b/src/script/lua_api/l_server.cpp
index 74ee5e5c9a..698b2dba67 100644
--- a/src/script/lua_api/l_server.cpp
+++ b/src/script/lua_api/l_server.cpp
@@ -261,7 +261,7 @@ int ModApiServer::l_get_player_information(lua_State *L)
 	lua_settable(L, table);
 
 	lua_pushstring(L,"state");
-	lua_pushstring(L, ClientInterface::state2Name(info.state).c_str());
+	lua_pushstring(L, ClientInterface::state2Name(info.state));
 	lua_settable(L, table);
 #endif
 
diff --git a/src/script/lua_api/l_vmanip.cpp b/src/script/lua_api/l_vmanip.cpp
index 5815d3bf3d..af254b1056 100644
--- a/src/script/lua_api/l_vmanip.cpp
+++ b/src/script/lua_api/l_vmanip.cpp
@@ -44,7 +44,40 @@ int LuaVoxelManip::l_read_from_map(lua_State *L)
 
 	push_v3s16(L, vm->m_area.MinEdge);
 	push_v3s16(L, vm->m_area.MaxEdge);
+	return 2;
+}
 
+int LuaVoxelManip::l_initialize(lua_State *L)
+{
+	MAP_LOCK_REQUIRED;
+
+	LuaVoxelManip *o = checkObject<LuaVoxelManip>(L, 1);
+	MMVManip *vm = o->vm;
+
+	if (o->is_mapgen_vm)
+		throw LuaError("Cannot modify mapgen VoxelManip object");
+
+	VoxelArea area;
+	{
+		v3s16 bp1 = getNodeBlockPos(check_v3s16(L, 2));
+		v3s16 bp2 = getNodeBlockPos(check_v3s16(L, 3));
+		sortBoxVerticies(bp1, bp2);
+		area = VoxelArea(bp1 * MAP_BLOCKSIZE, (bp2+1) * MAP_BLOCKSIZE - v3s16(1));
+	}
+	assert(!area.hasEmptyExtent());
+
+	vm->clear();
+	vm->addArea(area);
+	if (lua_istable(L, 4)) {
+		MapNode n = readnode(L, 4);
+		const u32 volume = vm->m_area.getVolume();
+		for (u32 i = 0; i != volume; i++)
+			vm->m_data[i] = n;
+		vm->clearFlags(vm->m_area, VOXELFLAG_NO_DATA);
+	}
+
+	push_v3s16(L, vm->m_area.MinEdge);
+	push_v3s16(L, vm->m_area.MaxEdge);
 	return 2;
 }
 
@@ -93,11 +126,12 @@ int LuaVoxelManip::l_set_data(lua_State *L)
 		lua_pop(L, 1);
 	}
 
-	// FIXME: in theory we should clear VOXELFLAG_NO_DATA here
-	// However there is no way to tell which values Lua code has intended to set
-	// (if they were VOXELFLAG_NO_DATA before), and which were just not touched.
-	// In practice this doesn't cause problems because read_from_map() will cause
-	// all covered blocks to be loaded anyway.
+	// Mark all data as present, since we just got it from Lua
+	// Note that we can't tell if the caller intended to put CONTENT_IGNORE or
+	// is just repeating the dummy values we push in l_get_data() in case
+	// VOXELFLAG_NO_DATA is set. In practice this doesn't matter since ignore
+	// isn't written back to the map anyway.
+	vm->clearFlags(vm->m_area, VOXELFLAG_NO_DATA);
 
 	return 0;
 }
@@ -344,6 +378,19 @@ int LuaVoxelManip::l_get_emerged_area(lua_State *L)
 	return 2;
 }
 
+int LuaVoxelManip::l_close(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+
+	LuaVoxelManip *o = checkObject<LuaVoxelManip>(L, 1);
+
+	if (o->is_mapgen_vm)
+		throw LuaError("Cannot dispose of mapgen VoxelManip object");
+	o->vm->clear();
+
+	return 0;
+}
+
 LuaVoxelManip::LuaVoxelManip(MMVManip *mmvm, bool is_mg_vm) :
 	is_mapgen_vm(is_mg_vm),
 	vm(mmvm)
@@ -436,6 +483,7 @@ void LuaVoxelManip::Register(lua_State *L)
 const char LuaVoxelManip::className[] = "VoxelManip";
 const luaL_Reg LuaVoxelManip::methods[] = {
 	luamethod(LuaVoxelManip, read_from_map),
+	luamethod(LuaVoxelManip, initialize),
 	luamethod(LuaVoxelManip, get_data),
 	luamethod(LuaVoxelManip, set_data),
 	luamethod(LuaVoxelManip, get_node_at),
@@ -451,5 +499,6 @@ const luaL_Reg LuaVoxelManip::methods[] = {
 	luamethod(LuaVoxelManip, set_param2_data),
 	luamethod(LuaVoxelManip, was_modified),
 	luamethod(LuaVoxelManip, get_emerged_area),
+	luamethod(LuaVoxelManip, close),
 	{0,0}
 };
diff --git a/src/script/lua_api/l_vmanip.h b/src/script/lua_api/l_vmanip.h
index 5ba1caffa4..95bb82ce22 100644
--- a/src/script/lua_api/l_vmanip.h
+++ b/src/script/lua_api/l_vmanip.h
@@ -24,6 +24,7 @@ private:
 	static int gc_object(lua_State *L);
 
 	static int l_read_from_map(lua_State *L);
+	static int l_initialize(lua_State *L);
 	static int l_get_data(lua_State *L);
 	static int l_set_data(lua_State *L);
 	static int l_write_to_map(lua_State *L);
@@ -45,6 +46,8 @@ private:
 	static int l_was_modified(lua_State *L);
 	static int l_get_emerged_area(lua_State *L);
 
+	static int l_close(lua_State *L);
+
 public:
 	MMVManip *vm = nullptr;
 
diff --git a/src/server.cpp b/src/server.cpp
index 008b91022b..a1263ef1dc 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -1572,7 +1572,8 @@ void Server::SendChatMessage(session_t peer_id, const ChatMessage &message)
 	if (peer_id != PEER_ID_INEXISTENT) {
 		Send(&pkt);
 	} else {
-		m_clients.sendToAll(&pkt);
+		// If a client has completed auth but is still joining, still send chat
+		m_clients.sendToAll(&pkt, CS_InitDone);
 	}
 }
 
@@ -3183,9 +3184,7 @@ std::wstring Server::handleChat(const std::string &name,
 
 	ChatMessage chatmsg(line);
 
-	std::vector<session_t> clients = m_clients.getClientIDs();
-	for (u16 cid : clients)
-		SendChatMessage(cid, chatmsg);
+	SendChatMessage(PEER_ID_INEXISTENT, chatmsg);
 
 	return L"";
 }
@@ -3357,6 +3356,15 @@ bool Server::denyIfBanned(session_t peer_id)
 	return false;
 }
 
+bool Server::checkUserLimit(const std::string &player_name, const std::string &addr_s)
+{
+	if (!m_clients.isUserLimitReached())
+		return false;
+	if (player_name == g_settings->get("name")) // admin can always join
+		return false;
+	return !m_script->can_bypass_userlimit(player_name, addr_s);
+}
+
 void Server::notifyPlayer(const char *name, const std::wstring &msg)
 {
 	// m_env will be NULL if the server is initializing
@@ -3490,7 +3498,6 @@ void Server::hudSetHotbarSelectedImage(RemotePlayer *player, const std::string &
 
 Address Server::getPeerAddress(session_t peer_id)
 {
-	// Note that this is only set after Init was received in Server::handleCommand_Init
 	return getClient(peer_id, CS_Invalid)->getAddress();
 }
 
diff --git a/src/server.h b/src/server.h
index c9869e1ddf..ae5b106828 100644
--- a/src/server.h
+++ b/src/server.h
@@ -368,6 +368,7 @@ public:
 	void hudSetHotbarImage(RemotePlayer *player, const std::string &name);
 	void hudSetHotbarSelectedImage(RemotePlayer *player, const std::string &name);
 
+	/// @note this is only available for client state >= CS_HelloSent
 	Address getPeerAddress(session_t peer_id);
 
 	void setLocalPlayerAnimations(RemotePlayer *player, v2f animation_frames[4],
@@ -611,6 +612,10 @@ private:
 
 	void handleChatInterfaceEvent(ChatEvent *evt);
 
+	/// @brief Checks if user limit allows a potential client to join
+	/// @return true if the client can NOT join
+	bool checkUserLimit(const std::string &player_name, const std::string &addr_s);
+
 	// This returns the answer to the sender of wmessage, or "" if there is none
 	std::wstring handleChat(const std::string &name, std::wstring wmessage_input,
 		bool check_shout_priv = false, RemotePlayer *player = nullptr);
diff --git a/src/server/clientiface.cpp b/src/server/clientiface.cpp
index 13cf14c07a..bbcd4720db 100644
--- a/src/server/clientiface.cpp
+++ b/src/server/clientiface.cpp
@@ -47,7 +47,7 @@ const char *ClientInterface::statenames[] = {
 	"SudoMode",
 };
 
-std::string ClientInterface::state2Name(ClientState state)
+const char *ClientInterface::state2Name(ClientState state)
 {
 	return statenames[state];
 }
@@ -659,7 +659,7 @@ std::vector<session_t> ClientInterface::getClientIDs(ClientState min_state)
 {
 	std::vector<session_t> reply;
 	RecursiveMutexAutoLock clientslock(m_clients_mutex);
-
+	reply.reserve(m_clients.size());
 	for (const auto &m_client : m_clients) {
 		if (m_client.second->getState() >= min_state)
 			reply.push_back(m_client.second->peer_id);
@@ -677,14 +677,10 @@ void ClientInterface::markBlocksNotSent(const std::vector<v3s16> &positions, boo
 	}
 }
 
-/**
- * Verify if user limit was reached.
- * User limit count all clients from HelloSent state (MT protocol user) to Active state
- * @return true if user limit was reached
- */
 bool ClientInterface::isUserLimitReached()
 {
-	return getClientIDs(CS_HelloSent).size() >= g_settings->getU16("max_users");
+	// Note that this only counts clients that have fully joined
+	return getClientIDs().size() >= g_settings->getU16("max_users");
 }
 
 void ClientInterface::step(float dtime)
@@ -703,16 +699,13 @@ void ClientInterface::step(float dtime)
 	RecursiveMutexAutoLock clientslock(m_clients_mutex);
 	for (const auto &it : m_clients) {
 		auto state = it.second->getState();
-		if (state >= CS_HelloSent)
+		if (state >= CS_InitDone)
 			continue;
 		if (it.second->uptime() <= LINGER_TIMEOUT)
 			continue;
-		// CS_Created means nobody has even noticed the client is there
-		//            (this is before on_prejoinplayer runs)
-		// CS_Invalid should not happen
-		// -> log those as warning, the rest as info
-		std::ostream &os = state == CS_Created || state == CS_Invalid ?
-			warningstream : infostream;
+		// Complain louder if this situation is unexpected
+		auto &os = state == CS_Disconnecting || state == CS_Denied ?
+			infostream : warningstream;
 		try {
 			Address addr = m_con->GetPeerAddress(it.second->peer_id);
 			os << "Disconnecting lingering client from "
@@ -770,33 +763,22 @@ void ClientInterface::sendCustom(session_t peer_id, u8 channel, NetworkPacket *p
 	m_con->Send(peer_id, channel, pkt, reliable);
 }
 
-void ClientInterface::sendToAll(NetworkPacket *pkt)
+void ClientInterface::sendToAll(NetworkPacket *pkt, ClientState state_min)
 {
+	auto &ccf = clientCommandFactoryTable[pkt->getCommand()];
+	FATAL_ERROR_IF(!ccf.name, "packet type missing in table");
 	RecursiveMutexAutoLock clientslock(m_clients_mutex);
-	for (auto &client_it : m_clients) {
-		RemoteClient *client = client_it.second;
-
-		if (client->net_proto_version != 0) {
-			auto &ccf = clientCommandFactoryTable[pkt->getCommand()];
-			FATAL_ERROR_IF(!ccf.name, "packet type missing in table");
-			m_con->Send(client->peer_id, ccf.channel, pkt, ccf.reliable);
-		}
+	for (auto &[peer_id, client] : m_clients) {
+		if (client->getState() >= state_min)
+			m_con->Send(peer_id, ccf.channel, pkt, ccf.reliable);
 	}
 }
 
 RemoteClient* ClientInterface::getClientNoEx(session_t peer_id, ClientState state_min)
 {
 	RecursiveMutexAutoLock clientslock(m_clients_mutex);
-	RemoteClientMap::const_iterator n = m_clients.find(peer_id);
-	// The client may not exist; clients are immediately removed if their
-	// access is denied, and this event occurs later then.
-	if (n == m_clients.end())
-		return NULL;
-
-	if (n->second->getState() >= state_min)
-		return n->second;
-
-	return NULL;
+	RemoteClient *client = lockedGetClientNoEx(peer_id, state_min);
+	return client;
 }
 
 RemoteClient* ClientInterface::lockedGetClientNoEx(session_t peer_id, ClientState state_min)
@@ -805,12 +787,13 @@ RemoteClient* ClientInterface::lockedGetClientNoEx(session_t peer_id, ClientStat
 	// The client may not exist; clients are immediately removed if their
 	// access is denied, and this event occurs later then.
 	if (n == m_clients.end())
-		return NULL;
+		return nullptr;
 
+	assert(n->second->peer_id == peer_id);
 	if (n->second->getState() >= state_min)
 		return n->second;
 
-	return NULL;
+	return nullptr;
 }
 
 ClientState ClientInterface::getClientState(session_t peer_id)
@@ -825,16 +808,6 @@ ClientState ClientInterface::getClientState(session_t peer_id)
 	return n->second->getState();
 }
 
-void ClientInterface::setPlayerName(session_t peer_id, const std::string &name)
-{
-	RecursiveMutexAutoLock clientslock(m_clients_mutex);
-	RemoteClientMap::iterator n = m_clients.find(peer_id);
-	// The client may not exist; clients are immediately removed if their
-	// access is denied, and this event occurs later then.
-	if (n != m_clients.end())
-		n->second->setName(name);
-}
-
 void ClientInterface::DeleteClient(session_t peer_id)
 {
 	RecursiveMutexAutoLock conlock(m_clients_mutex);
@@ -915,18 +888,3 @@ u16 ClientInterface::getProtocolVersion(session_t peer_id)
 
 	return n->second->net_proto_version;
 }
-
-void ClientInterface::setClientVersion(session_t peer_id, u8 major, u8 minor, u8 patch,
-		const std::string &full)
-{
-	RecursiveMutexAutoLock conlock(m_clients_mutex);
-
-	// Error check
-	RemoteClientMap::iterator n = m_clients.find(peer_id);
-
-	// No client to set versions
-	if (n == m_clients.end())
-		return;
-
-	n->second->setVersionInfo(major, minor, patch, full);
-}
diff --git a/src/server/clientiface.h b/src/server/clientiface.h
index 44b278e63e..d0e91dcca3 100644
--- a/src/server/clientiface.h
+++ b/src/server/clientiface.h
@@ -445,7 +445,7 @@ public:
 	/* mark blocks as not sent on all active clients */
 	void markBlocksNotSent(const std::vector<v3s16> &positions, bool low_priority = false);
 
-	/* verify is server user limit was reached */
+	/* verify if server user limit was reached */
 	bool isUserLimitReached();
 
 	/* get list of client player names */
@@ -458,7 +458,7 @@ public:
 	void sendCustom(session_t peer_id, u8 channel, NetworkPacket *pkt, bool reliable);
 
 	/* send to all clients */
-	void sendToAll(NetworkPacket *pkt);
+	void sendToAll(NetworkPacket *pkt, ClientState state_min = CS_Active);
 
 	/* delete a client */
 	void DeleteClient(session_t peer_id);
@@ -475,16 +475,9 @@ public:
 	/* get state of client by id*/
 	ClientState getClientState(session_t peer_id);
 
-	/* set client playername */
-	void setPlayerName(session_t peer_id, const std::string &name);
-
 	/* get protocol version of client */
 	u16 getProtocolVersion(session_t peer_id);
 
-	/* set client version */
-	void setClientVersion(session_t peer_id, u8 major, u8 minor, u8 patch,
-			const std::string &full);
-
 	/* event to update client state */
 	void event(session_t peer_id, ClientStateEvent event);
 
@@ -495,7 +488,8 @@ public:
 		m_env = env;
 	}
 
-	static std::string state2Name(ClientState state);
+	static const char *state2Name(ClientState state);
+
 protected:
 	class AutoLock {
 	public:
@@ -514,9 +508,9 @@ private:
 	// Connection
 	std::shared_ptr<con::IConnection> m_con;
 	std::recursive_mutex m_clients_mutex;
-	// Connected clients (behind the con mutex)
+	// Connected clients (behind the mutex)
 	RemoteClientMap m_clients;
-	std::vector<std::string> m_clients_names; //for announcing masterserver
+	std::vector<std::string> m_clients_names; // for announcing to server list
 
 	// Environment
 	ServerEnvironment *m_env;
@@ -526,5 +520,7 @@ private:
 
 	static const char *statenames[];
 
-	static constexpr int LINGER_TIMEOUT = 10;
+	// Note that this puts a fixed timeout on the init & auth phase for a client.
+	// (lingering is enforced until CS_InitDone)
+	static constexpr int LINGER_TIMEOUT = 12;
 };
diff --git a/src/unittest/test_voxelarea.cpp b/src/unittest/test_voxelarea.cpp
index d9380caf9e..52bf1bfd89 100644
--- a/src/unittest/test_voxelarea.cpp
+++ b/src/unittest/test_voxelarea.cpp
@@ -264,6 +264,10 @@ void TestVoxelArea::test_intersect()
 	UASSERT(v3.intersect(v1) == v1.intersect(v3));
 	UASSERT(v1.intersect(v4) ==
 			VoxelArea({-10, -2, -10}, {10, 2, 10}));
+
+	// edge cases
+	UASSERT(VoxelArea().intersect(v1).hasEmptyExtent());
+	UASSERT(v1.intersect(VoxelArea()).hasEmptyExtent());
 }
 
 void TestVoxelArea::test_index_xyz_all_pos()
diff --git a/src/unittest/test_voxelmanipulator.cpp b/src/unittest/test_voxelmanipulator.cpp
index 09d4b5781e..9c1f85d242 100644
--- a/src/unittest/test_voxelmanipulator.cpp
+++ b/src/unittest/test_voxelmanipulator.cpp
@@ -4,11 +4,13 @@
 
 #include "test.h"
 
-#include <algorithm>
+#include <memory>
 
 #include "gamedef.h"
 #include "log.h"
 #include "voxel.h"
+#include "dummymap.h"
+#include "irrlicht_changes/printing.h"
 
 class TestVoxelManipulator : public TestBase {
 public:
@@ -17,59 +19,32 @@ public:
 
 	void runTests(IGameDef *gamedef);
 
-	void testVoxelArea();
-	void testVoxelManipulator(const NodeDefManager *nodedef);
+	void testBasic(const NodeDefManager *nodedef);
+	void testEmerge(IGameDef *gamedef);
+	void testBlitBack(IGameDef *gamedef);
+	void testBlitBack2(IGameDef *gamedef);
 };
 
 static TestVoxelManipulator g_test_instance;
 
 void TestVoxelManipulator::runTests(IGameDef *gamedef)
 {
-	TEST(testVoxelArea);
-	TEST(testVoxelManipulator, gamedef->getNodeDefManager());
+	TEST(testBasic, gamedef->ndef());
+	TEST(testEmerge, gamedef);
+	TEST(testBlitBack, gamedef);
+	TEST(testBlitBack2, gamedef);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-void TestVoxelManipulator::testVoxelArea()
-{
-	VoxelArea a(v3s16(-1,-1,-1), v3s16(1,1,1));
-	UASSERT(a.index(0,0,0) == 1*3*3 + 1*3 + 1);
-	UASSERT(a.index(-1,-1,-1) == 0);
-
-	VoxelArea c(v3s16(-2,-2,-2), v3s16(2,2,2));
-	// An area that is 1 bigger in x+ and z-
-	VoxelArea d(v3s16(-2,-2,-3), v3s16(3,2,2));
-
-	std::list<VoxelArea> aa;
-	d.diff(c, aa);
-
-	// Correct results
-	std::vector<VoxelArea> results;
-	results.emplace_back(v3s16(-2,-2,-3), v3s16(3,2,-3));
-	results.emplace_back(v3s16(3,-2,-2), v3s16(3,2,2));
-
-	UASSERT(aa.size() == results.size());
-
-	infostream<<"Result of diff:"<<std::endl;
-	for (auto it = aa.begin(); it != aa.end(); ++it) {
-		it->print(infostream);
-		infostream << std::endl;
-
-		auto j = std::find(results.begin(), results.end(), *it);
-		UASSERT(j != results.end());
-		results.erase(j);
-	}
-}
-
-
-void TestVoxelManipulator::testVoxelManipulator(const NodeDefManager *nodedef)
+void TestVoxelManipulator::testBasic(const NodeDefManager *nodedef)
 {
 	VoxelManipulator v;
 
 	v.print(infostream, nodedef);
+	UASSERT(v.m_area.hasEmptyExtent());
 
-	infostream << "*** Setting (-1,0,-1)=2 ***" << std::endl;
+	infostream << "*** Setting (-1,0,-1) ***" << std::endl;
 	v.setNode(v3s16(-1,0,-1), MapNode(t_CONTENT_GRASS));
 
 	v.print(infostream, nodedef);
@@ -89,3 +64,118 @@ void TestVoxelManipulator::testVoxelManipulator(const NodeDefManager *nodedef)
 	UASSERT(v.getNode(v3s16(-1,0,-1)).getContent() == t_CONTENT_GRASS);
 	EXCEPTION_CHECK(InvalidPositionException, v.getNode(v3s16(0,1,1)));
 }
+
+void TestVoxelManipulator::testEmerge(IGameDef *gamedef)
+{
+	constexpr int bs = MAP_BLOCKSIZE;
+
+	DummyMap map(gamedef, {0,0,0}, {1,1,1});
+	map.fill({0,0,0}, {1,1,1}, CONTENT_AIR);
+
+	MMVManip vm(&map);
+	UASSERT(!vm.isOrphan());
+
+	// emerge something
+	vm.initialEmerge({0,0,0}, {0,0,0});
+	UASSERTEQ(auto, vm.m_area.MinEdge, v3s16(0));
+	UASSERTEQ(auto, vm.m_area.MaxEdge, v3s16(bs-1));
+	UASSERTEQ(auto, vm.getNodeNoExNoEmerge({0,0,0}).getContent(), CONTENT_AIR);
+
+	map.setNode({0,   1,0}, t_CONTENT_BRICK);
+	map.setNode({0,bs+1,0}, t_CONTENT_BRICK);
+
+	// emerge top block: this should not re-read the first one
+	vm.initialEmerge({0,0,0}, {0,1,0});
+	UASSERTEQ(auto, vm.m_area.getExtent(), v3s32(bs,2*bs,bs));
+
+	UASSERTEQ(auto, vm.getNodeNoExNoEmerge({0,   1,0}).getContent(), CONTENT_AIR);
+	UASSERTEQ(auto, vm.getNodeNoExNoEmerge({0,bs+1,0}).getContent(), t_CONTENT_BRICK);
+
+	// emerge out of bounds: should produce empty data
+	vm.initialEmerge({0,2,0}, {0,2,0}, false);
+	UASSERTEQ(auto, vm.m_area.getExtent(), v3s32(bs,3*bs,bs));
+
+	UASSERTEQ(auto, vm.getNodeNoExNoEmerge({0,2*bs,0}).getContent(), CONTENT_IGNORE);
+	UASSERT(!vm.exists({0,2*bs,0}));
+
+	// clear
+	vm.clear();
+	UASSERT(vm.m_area.hasEmptyExtent());
+}
+
+void TestVoxelManipulator::testBlitBack(IGameDef *gamedef)
+{
+	DummyMap map(gamedef, {-1,-1,-1}, {1,1,1});
+	map.fill({0,0,0}, {0,0,0}, CONTENT_AIR);
+
+	std::unique_ptr<MMVManip> vm2;
+
+	{
+		MMVManip vm(&map);
+		vm.initialEmerge({0,0,0}, {0,0,0});
+		UASSERT(vm.exists({0,0,0}));
+		vm.setNodeNoEmerge({0,0,0}, t_CONTENT_STONE);
+		vm.setNodeNoEmerge({1,1,1}, t_CONTENT_GRASS);
+		vm.setNodeNoEmerge({2,2,2}, CONTENT_IGNORE);
+		// test out clone and reparent too
+		vm2.reset(vm.clone());
+	}
+
+	UASSERT(vm2);
+	UASSERT(vm2->isOrphan());
+	vm2->reparent(&map);
+
+	std::map<v3s16, MapBlock*> modified;
+	vm2->blitBackAll(&modified);
+	UASSERTEQ(size_t, modified.size(), 1);
+	UASSERTEQ(auto, modified.begin()->first, v3s16(0,0,0));
+
+	UASSERTEQ(auto, map.getNode({0,0,0}).getContent(), t_CONTENT_STONE);
+	UASSERTEQ(auto, map.getNode({1,1,1}).getContent(), t_CONTENT_GRASS);
+	// ignore nodes are not written (is this an intentional feature?)
+	UASSERTEQ(auto, map.getNode({2,2,2}).getContent(), CONTENT_AIR);
+}
+
+void TestVoxelManipulator::testBlitBack2(IGameDef *gamedef)
+{
+	constexpr int bs = MAP_BLOCKSIZE;
+
+	DummyMap map(gamedef, {0,0,0}, {1,1,1});
+	map.fill({0,0,0}, {1,1,1}, CONTENT_AIR);
+
+	// Create a vmanip "manually" without using initialEmerge
+	MMVManip vm(&map);
+	vm.addArea(VoxelArea({0,0,0}, v3s16(1,2,1) * bs - v3s16(1)));
+
+	// Lower block is initialized with ignore, upper with lava
+	for(s16 z=0; z<bs; z++)
+	for(s16 y=0; y<2*bs; y++)
+	for(s16 x=0; x<bs; x++) {
+		auto c = y >= bs ? t_CONTENT_LAVA : CONTENT_IGNORE;
+		vm.setNodeNoEmerge({x,y,z}, c);
+	}
+	// But pretend the upper block was not actually initialized
+	vm.setFlags(VoxelArea({0,bs,0}, v3s16(1,2,1) * bs - v3s16(1)), VOXELFLAG_NO_DATA);
+	// Add a node to the lower one
+	vm.setNodeNoEmerge({0,1,0}, t_CONTENT_TORCH);
+
+	// Verify covered blocks
+	{
+		auto cov = vm.getCoveredBlocks();
+		UASSERTEQ(size_t, cov.size(), 2);
+		auto it = cov.find({0,0,0});
+		UASSERT(it != cov.end() && it->second);
+		it = cov.find({0,1,0});
+		UASSERT(it != cov.end() && !it->second);
+	}
+
+	// Now blit it back
+	std::map<v3s16, MapBlock*> modified;
+	vm.blitBackAll(&modified);
+	// The lower block data should have been written
+	UASSERTEQ(size_t, modified.size(), 1);
+	UASSERTEQ(auto, modified.begin()->first, v3s16(0,0,0));
+	UASSERTEQ(auto, map.getNode({0,1,0}).getContent(), t_CONTENT_TORCH);
+	// The upper one should not!
+	UASSERTEQ(auto, map.getNode({0,bs,0}).getContent(), CONTENT_AIR);
+}
diff --git a/src/voxel.cpp b/src/voxel.cpp
index 4d0ce84b7f..5a69b07255 100644
--- a/src/voxel.cpp
+++ b/src/voxel.cpp
@@ -15,7 +15,6 @@
 	Debug stuff
 */
 u64 emerge_time = 0;
-u64 emerge_load_time = 0;
 
 VoxelManipulator::~VoxelManipulator()
 {
diff --git a/src/voxel.h b/src/voxel.h
index c47f97a300..7fbaadc281 100644
--- a/src/voxel.h
+++ b/src/voxel.h
@@ -34,7 +34,6 @@ class NodeDefManager;
 	Debug stuff
 */
 extern u64 emerge_time;
-extern u64 emerge_load_time;
 
 /*
 	This class resembles aabbox3d<s16> a lot, but has inclusive
@@ -469,7 +468,7 @@ public:
 		Control
 	*/
 
-	virtual void clear();
+	void clear();
 
 	void print(std::ostream &o, const NodeDefManager *nodemgr,
 			VoxelPrintMode mode=VOXELPRINT_MATERIAL) const;