diff --git a/.gitignore b/.gitignore
index c21162d6..85f580bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,12 @@ htop
 # all object files
 *.o
 
+*.gcda
+*/*.gcda
+*.gcno
+*/*.gcno
+*.h.gch
+
 .deps/
 Makefile
 Makefile.in
diff --git a/Panel.c b/Panel.c
index ccf6ba68..7428dda6 100644
--- a/Panel.c
+++ b/Panel.c
@@ -56,7 +56,6 @@ typedef struct PanelClass_ {
 
 struct Panel_ {
    Object super;
-   PanelClass* class;
    int x, y, w, h;
    WINDOW* window;
    Vector* items;
diff --git a/Panel.h b/Panel.h
index 71740bf6..2e9c5ad3 100644
--- a/Panel.h
+++ b/Panel.h
@@ -45,7 +45,6 @@ typedef struct PanelClass_ {
 
 struct Panel_ {
    Object super;
-   PanelClass* class;
    int x, y, w, h;
    WINDOW* window;
    Vector* items;
diff --git a/Process.c b/Process.c
index 3d95ce00..267d1733 100644
--- a/Process.c
+++ b/Process.c
@@ -149,7 +149,15 @@ extern ProcessFieldData Process_fields[];
 extern char* Process_pidFormat;
 extern char* Process_tpgidFormat;
 
-typedef Process*(*Process_new_fn)(struct Settings_*);
+typedef Process*(*Process_New)(struct Settings_*);
+typedef void (*Process_WriteField)(Process*, RichString*, ProcessField);
+
+typedef struct ProcessClass_ {
+   const ObjectClass super;
+   const Process_WriteField writeField;
+} ProcessClass;
+
+#define As_Process(this_)              ((ProcessClass*)((this_)->super.klass))
 
 }*/
 
@@ -306,7 +314,7 @@ void Process_outputRate(RichString* str, char* buffer, int n, double rate, int c
    }
 }
 
-void Process_writeDefaultField(Process* this, RichString* str, ProcessField field) {
+void Process_writeField(Process* this, RichString* str, ProcessField field) {
    char buffer[256]; buffer[255] = '\0';
    int attr = CRT_colors[DEFAULT_COLOR];
    int baseattr = CRT_colors[PROCESS_BASENAME];
@@ -427,12 +435,12 @@ void Process_writeDefaultField(Process* this, RichString* str, ProcessField fiel
    RichString_append(str, attr, buffer);
 }
 
-static void Process_display(Object* cast, RichString* out) {
+void Process_display(Object* cast, RichString* out) {
    Process* this = (Process*) cast;
    ProcessField* fields = this->settings->fields;
    RichString_prune(out);
    for (int i = 0; fields[i]; i++)
-      Process_writeField(this, out, fields[i]);
+      As_Process(this)->writeField(this, out, fields[i]);
    if (this->settings->shadowOtherUsers && (int)this->st_uid != Process_getuid)
       RichString_setAttr(out, CRT_colors[PROCESS_SHADOW]);
    if (this->tag == true)
@@ -445,11 +453,14 @@ void Process_done(Process* this) {
    free(this->comm);
 }
 
-ObjectClass Process_class = {
-   .extends = Class(Object),
-   .display = Process_display,
-   .delete = Process_delete,
-   .compare = Process_compare
+ProcessClass Process_class = {
+   .super = {
+      .extends = Class(Object),
+      .display = Process_display,
+      .delete = Process_delete,
+      .compare = Process_compare
+   },
+   .writeField = Process_writeField,
 };
 
 void Process_init(Process* this, struct Settings_* settings) {
@@ -489,7 +500,7 @@ long Process_pidCompare(const void* v1, const void* v2) {
    return (p1->pid - p2->pid);
 }
 
-long Process_defaultCompare(const void* v1, const void* v2) {
+long Process_compare(const void* v1, const void* v2) {
    Process *p1, *p2;
    Settings *settings = ((Process*)v1)->settings;
    if (settings->direction == 1) {
diff --git a/Process.h b/Process.h
index 341c0e82..e1b7a8fa 100644
--- a/Process.h
+++ b/Process.h
@@ -130,7 +130,15 @@ extern ProcessFieldData Process_fields[];
 extern char* Process_pidFormat;
 extern char* Process_tpgidFormat;
 
-typedef Process*(*Process_new_fn)(struct Settings_*);
+typedef Process*(*Process_New)(struct Settings_*);
+typedef void (*Process_WriteField)(Process*, RichString*, ProcessField);
+
+typedef struct ProcessClass_ {
+   const ObjectClass super;
+   const Process_WriteField writeField;
+} ProcessClass;
+
+#define As_Process(this_)              ((ProcessClass*)((this_)->super.klass))
 
 
 #define ONE_K 1024L
@@ -149,11 +157,13 @@ void Process_printTime(RichString* str, unsigned long long totalHundredths);
 
 void Process_outputRate(RichString* str, char* buffer, int n, double rate, int coloring);
 
-void Process_writeDefaultField(Process* this, RichString* str, ProcessField field);
+void Process_writeField(Process* this, RichString* str, ProcessField field);
+
+void Process_display(Object* cast, RichString* out);
 
 void Process_done(Process* this);
 
-extern ObjectClass Process_class;
+extern ProcessClass Process_class;
 
 void Process_init(Process* this, struct Settings_* settings);
 
@@ -167,6 +177,6 @@ void Process_sendSignal(Process* this, size_t sgn);
 
 long Process_pidCompare(const void* v1, const void* v2);
 
-long Process_defaultCompare(const void* v1, const void* v2);
+long Process_compare(const void* v1, const void* v2);
 
 #endif
diff --git a/ProcessList.c b/ProcessList.c
index 229e370d..7fbe6c3a 100644
--- a/ProcessList.c
+++ b/ProcessList.c
@@ -287,7 +287,7 @@ void ProcessList_rebuildPanel(ProcessList* this) {
    }
 }
 
-Process* ProcessList_getProcess(ProcessList* this, pid_t pid, bool* preExisting, Process_new_fn constructor) {
+Process* ProcessList_getProcess(ProcessList* this, pid_t pid, bool* preExisting, Process_New constructor) {
    Process* proc = (Process*) Hashtable_get(this->processTable, pid);
    *preExisting = proc;
    if (proc) {
diff --git a/ProcessList.h b/ProcessList.h
index 9465e82e..e00585fd 100644
--- a/ProcessList.h
+++ b/ProcessList.h
@@ -91,7 +91,7 @@ void ProcessList_expandTree(ProcessList* this);
 
 void ProcessList_rebuildPanel(ProcessList* this);
 
-Process* ProcessList_getProcess(ProcessList* this, pid_t pid, bool* preExisting, Process_new_fn constructor);
+Process* ProcessList_getProcess(ProcessList* this, pid_t pid, bool* preExisting, Process_New constructor);
 
 void ProcessList_scan(ProcessList* this);
 
diff --git a/linux/LinuxProcess.c b/linux/LinuxProcess.c
index 409a4ae5..0e73b20a 100644
--- a/linux/LinuxProcess.c
+++ b/linux/LinuxProcess.c
@@ -261,9 +261,19 @@ void Process_setupColumnWidths() {
    }
 }
 
+ProcessClass LinuxProcess_class = {
+   .super = {
+      .extends = Class(Process),
+      .display = Process_display,
+      .delete = Process_delete,
+      .compare = LinuxProcess_compare
+   },
+   .writeField = (Process_WriteField) LinuxProcess_writeField,
+};
+
 LinuxProcess* LinuxProcess_new(Settings* settings) {
    LinuxProcess* this = calloc(sizeof(LinuxProcess), 1);
-   Object_setClass(this, Class(Process));
+   Object_setClass(this, Class(LinuxProcess));
    Process_init(&this->super, settings);
    return this;
 }
@@ -298,7 +308,7 @@ bool LinuxProcess_setIOPriority(LinuxProcess* this, IOPriority ioprio) {
    return (LinuxProcess_updateIOPriority(this) == ioprio);
 }
 
-void Process_writeField(Process* this, RichString* str, ProcessField field) {
+void LinuxProcess_writeField(Process* this, RichString* str, ProcessField field) {
    LinuxProcess* lp = (LinuxProcess*) this;
    bool coloring = this->settings->highlightMegabytes;
    char buffer[256]; buffer[255] = '\0';
@@ -360,13 +370,13 @@ void Process_writeField(Process* this, RichString* str, ProcessField field) {
       break;
    }
    default:
-      Process_writeDefaultField(this, str, field);
+      Process_writeField((Process*)this, str, field);
       return;
    }
    RichString_append(str, attr, buffer);
 }
 
-long Process_compare(const void* v1, const void* v2) {
+long LinuxProcess_compare(const void* v1, const void* v2) {
    LinuxProcess *p1, *p2;
    Settings *settings = ((Process*)v1)->settings;
    if (settings->direction == 1) {
@@ -425,7 +435,7 @@ long Process_compare(const void* v1, const void* v2) {
    case IO_PRIORITY:
       return LinuxProcess_effectiveIOPriority(p1) - LinuxProcess_effectiveIOPriority(p2);
    default:
-      return Process_defaultCompare(v1, v2);
+      return Process_compare(v1, v2);
    }
    test_diff:
    return (diff > 0) ? 1 : (diff < 0 ? -1 : 0);
diff --git a/linux/LinuxProcess.h b/linux/LinuxProcess.h
index 55fa1b9e..bfc70234 100644
--- a/linux/LinuxProcess.h
+++ b/linux/LinuxProcess.h
@@ -137,6 +137,8 @@ extern char* Process_tpgidFormat;
 
 void Process_setupColumnWidths();
 
+extern ProcessClass LinuxProcess_class;
+
 LinuxProcess* LinuxProcess_new(Settings* settings);
 
 void Process_delete(Object* cast);
@@ -155,9 +157,9 @@ IOPriority LinuxProcess_updateIOPriority(LinuxProcess* this);
 
 bool LinuxProcess_setIOPriority(LinuxProcess* this, IOPriority ioprio);
 
-void Process_writeField(Process* this, RichString* str, ProcessField field);
+void LinuxProcess_writeField(Process* this, RichString* str, ProcessField field);
 
-long Process_compare(const void* v1, const void* v2);
+long LinuxProcess_compare(const void* v1, const void* v2);
 
 bool Process_isThread(Process* this);
 
diff --git a/linux/LinuxProcessList.c b/linux/LinuxProcessList.c
index 1c5f2059..b9c4073c 100644
--- a/linux/LinuxProcessList.c
+++ b/linux/LinuxProcessList.c
@@ -517,7 +517,7 @@ static bool LinuxProcessList_recurseProcTree(LinuxProcessList* this, const char*
          continue;
 
       bool preExisting = false;
-      Process* proc = ProcessList_getProcess(pl, pid, &preExisting, (Process_new_fn) LinuxProcess_new);
+      Process* proc = ProcessList_getProcess(pl, pid, &preExisting, (Process_New) LinuxProcess_new);
       proc->tgid = parent ? parent->pid : pid;
       
       LinuxProcess* lp = (LinuxProcess*) proc;
diff --git a/test_spec.lua b/test_spec.lua
index 38f27b53..e57437d6 100755
--- a/test_spec.lua
+++ b/test_spec.lua
@@ -20,7 +20,7 @@ os.execute("killall htop")
 os.execute("ps aux | grep '[s]leep 12345' | awk '{print $2}' | xargs kill 2> /dev/null")
 
 os.execute("cp ./default.htoprc ./test.htoprc")
-rt:forkPty("HTOPRC=./test.htoprc ./htop")
+rt:forkPty("LC_ALL=C HTOPRC=./test.htoprc ./htop")
 
 local stdscr, term_win
 -- Curses initalization needed even when not in visual mode
@@ -68,7 +68,7 @@ end
 
 local function send(key, times)
    if times == 0 then return end
-   for i = 1, times or 1 do 
+   for _ = 1, times or 1 do
       delay(0.003) -- 30ms delay to avoid clobbering Esc sequences
       if type(key) == "string" then
          for c in key:gmatch('.') do
@@ -138,8 +138,9 @@ local attrs = {
    red_on_cyan = 22,
 }
 
-local function find_selected_y()
-   for y = y_panelhdr + 1, rt:rows() - 1 do
+local function find_selected_y(from)
+   rt:update()
+   for y = from or (y_panelhdr + 1), rt:rows() - 1 do
       local attr = rt:cellAttr(y-1, 1)
       if attr == attrs.black_on_cyan then
          return y
@@ -161,7 +162,7 @@ describe("htop test suite", function()
    
    running_it("performs incremental filter", function()
       send("\\")
-      send("busted")
+      send("x\127bux\127sted") -- test backspace
       send("\n")
       delay(0.2)
       rt:update()
@@ -188,7 +189,6 @@ describe("htop test suite", function()
       local attr = rt:cellAttr(rt:rows() - 1, 30)
       send("\n")
       delay(0.4)
-      rt:update()
       local line = find_selected_y()
       local pid = ("      "..tostring(unistd.getpid())):sub(-5)
       assert.equal(attr, attrs.black_on_cyan)
@@ -224,7 +224,6 @@ describe("htop test suite", function()
       send("\n")
       send("s")
       delay(1)
-      delay(1)
       send(ESC)
    end)
 
@@ -235,15 +234,48 @@ describe("htop test suite", function()
       send("\n")
       send("l")
       delay(1)
-      delay(1)
       send(ESC)
    end)
 
-   running_it("cycles through meter modes", function()
+   running_it("performs filtering in lsof", function()
+      send(curses.KEY_HOME)
+      send("/")
+      send("htop")
+      send("\n")
+      send("l")
+      send(curses.KEY_F4)
+      send("pipe")
+      delay(1)
+      local pipefd = check_string_at(1, 3, "    3")
+      send(ESC)
+      assert.equal(check(pipefd))
+   end)
+
+   running_it("performs search in lsof", function()
+      send(curses.KEY_HOME)
+      send("/")
+      send("htop")
+      send("\n")
+      send("l")
+      send(curses.KEY_F3)
+      send("pipe")
+      delay(1)
+      local line = find_selected_y(3)
+      local pipefd = check_string_at(1, line, "    3")
+      send(ESC)
+      assert.equal(check(pipefd))
+   end)
+
+
+   running_it("cycles through meter modes in the default meters", function()
       send("S")
-      send(curses.KEY_RIGHT)
-      send(curses.KEY_DOWN)
-      send("\n\n\n\n\n")
+      for _ = 1, 2 do
+         send(curses.KEY_RIGHT)
+         for _ = 1, 3 do
+            send("\n", 4)
+            send(curses.KEY_DOWN)
+         end
+      end
       send(ESC)
    end)
 
@@ -366,6 +398,7 @@ describe("htop test suite", function()
             send(curses.KEY_DOWN, 4)
             send(curses.KEY_F7, 4)
          end
+         send(curses.KEY_F4, 4) -- cycle through meter modes
          delay(0.15)
          rt:update()
          local with = check_string_at(x_metercol2, 2, item.string)
@@ -382,7 +415,7 @@ describe("htop test suite", function()
       send(curses.KEY_F2)
       send(curses.KEY_DOWN, 2)
       send(curses.KEY_RIGHT)
-      for i = 1, 6 do
+      for _ = 1, 6 do
          send("\n")
          send(curses.KEY_DOWN)
       end
@@ -420,8 +453,22 @@ describe("htop test suite", function()
          end
       end)
    end
+
+   running_it("shows detailed CPU with guest time", function()
+      for _ = 1, 2 do
+         send("S")
+         send(curses.KEY_DOWN)
+         send(curses.KEY_RIGHT)
+         send(curses.KEY_DOWN, 9)
+         send("\n")
+         send(curses.KEY_DOWN, 3)
+         send("\n")
+         send(curses.KEY_F10)
+         delay(0.1)
+      end
+   end)
    
-   for i = 1, 53 do
+   for i = 1, 62 do
       running_it("show column "..i, function()
          send("S")
          send(curses.KEY_END)