wm: Fix override-redirect window stacking bug.

src/platform/window_manager/real_compositor.cc

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "window_manager/compositor.h"
 
 #include <algorithm>
 #include <ctime>
 #include <string>
 
@@ skipping 209 matching lines @@
                duration_ms);
 }
 
 void RealCompositor::Actor::SetTilt(double tilt, int duration_ms) {
   AnimateField(&float_animations_, &tilt_,
                static_cast<float>(tilt),
                duration_ms);
 }
 
 void RealCompositor::Actor::Raise(Compositor::Actor* other) {
-  CHECK(parent_) << "Tried to raise an actor that has no parent.";
+  CHECK(parent_) << "Raising actor " << this << ", which has no parent";
+  if (other == this) {
+    LOG(DFATAL) << "Got request to raise actor " << this << " above itself";
+    return;
+  }
   RealCompositor::Actor* other_nc =
       dynamic_cast<RealCompositor::Actor*>(other);
-  CHECK(other_nc) << "Failed to cast to an Actor in Raise";
+  CHECK(other_nc) << "Failed to cast " << other << " to an Actor in Raise()";
   parent_->RaiseChild(this, other_nc);
   SetDirty();
 }
 
 void RealCompositor::Actor::Lower(Compositor::Actor* other) {
-  CHECK(parent_) << "Tried to lower an actor that has no parent.";
+  CHECK(parent_) << "Lowering actor " << this << ", which has no parent";
+  if (other == this) {
+    LOG(DFATAL) << "Got request to lower actor " << this << " below itself";
+    return;
+  }
   RealCompositor::Actor* other_nc =
       dynamic_cast<RealCompositor::Actor*>(other);
-  CHECK(other_nc) << "Failed to cast to an Actor in Lower";
+  CHECK(other_nc) << "Failed to cast " << other << " to an Actor in Lower()";
   parent_->LowerChild(this, other_nc);
   SetDirty();
 }
 
 void RealCompositor::Actor::RaiseToTop() {
-  CHECK(parent_) << "Tried to raise an actor to top that has no parent.";
+  CHECK(parent_) << "Raising actor " << this << ", which has no parent, to top";
   parent_->RaiseChild(this, NULL);
   SetDirty();
 }
 
 void RealCompositor::Actor::LowerToBottom() {
-  CHECK(parent_) << "Tried to lower an actor to bottom that has no parent.";
+  CHECK(parent_) << "Lowering actor " << this << ", which has no parent, "
+                 << "to bottom";
   parent_->LowerChild(this, NULL);
   SetDirty();
 }
 
 string RealCompositor::Actor::GetDebugStringInternal(const string& type_name,
                                                     int indent_level) {
   string out;
-  for (int i = 0; i < indent_level; ++i)
-    out += "  ";
-
+  out.assign(indent_level * 2, ' ');
   out += StringPrintf("\"%s\" %p (%s%s) (%d, %d) %dx%d "
                         "scale=(%.2f, %.2f) %.2f%% tilt=%0.2f\n",
                       !name_.empty() ? name_.c_str() : "",
                       this,
                       visible_ ? "" : "inv ",
                       type_name.c_str(),
                       x_, y_,
                       width_, height_,
                       scale_x_, scale_y_,
                       opacity_,
@@ skipping 496 matching lines @@
 }
 
 void RealCompositor::DisableDrawTimeout() {
   if (draw_timeout_enabled_) {
     event_loop_->SuspendTimeout(draw_timeout_id_);
     draw_timeout_enabled_ = false;
   }
 }
 
 }  // namespace window_manager