diff --git a/3rdparty/ocornut-imgui/imgui.cpp b/3rdparty/ocornut-imgui/imgui.cpp
index e5171ec92..f05990234 100644
--- a/3rdparty/ocornut-imgui/imgui.cpp
+++ b/3rdparty/ocornut-imgui/imgui.cpp
@@ -1991,8 +1991,9 @@ bool ImGui::ItemAdd(const ImRect& bb, ImGuiID id)
     return true;
 }
 
-// This is roughly matching the behavior of internal-facing ItemHoverable() which is 
+// This is roughly matching the behavior of internal-facing ItemHoverable()
 // - we allow hovering to be true when ActiveId==window->MoveID, so that clicking on non-interactive items such as a Text() item still returns true with IsItemHovered())
+// - this should work even for non-interactive items that have no ID, so we cannot use LastItemId
 bool ImGui::IsItemHovered()
 {
     ImGuiContext& g = *GImGui;
@@ -2000,7 +2001,11 @@ bool ImGui::IsItemHovered()
     ImGuiWindow* window = g.CurrentWindow;
     if (!window->DC.LastItemRectHoveredRect)
         return false;
-    if (g.HoveredWindow != window)
+    // [2017/10/16] Reverted commit 344d48be3 and testing RootWindow instead. I believe it is correct to NOT test for RootWindow but this leaves us unable to use IsItemHovered() after EndChild() itself.
+    // Until a solution is found I believe reverting to the test from 2017/09/27 is safe since this was the test that has been running for a long while.
+    //if (g.HoveredWindow != window)
+    //    return false;
+    if (g.HoveredRootWindow != window->RootWindow)
         return false;
     if (g.ActiveId != 0 && g.ActiveId != window->DC.LastItemId && !g.ActiveIdAllowOverlap && g.ActiveId != window->MoveId)
         return false;
diff --git a/3rdparty/ocornut-imgui/imgui_draw.cpp b/3rdparty/ocornut-imgui/imgui_draw.cpp
index dd579f4ca..b58507731 100644
--- a/3rdparty/ocornut-imgui/imgui_draw.cpp
+++ b/3rdparty/ocornut-imgui/imgui_draw.cpp
@@ -223,7 +223,7 @@ void ImDrawList::UpdateTextureID()
 
     // Try to merge with previous command if it matches, else use current command
     ImDrawCmd* prev_cmd = CmdBuffer.Size > 1 ? curr_cmd - 1 : NULL;
-    if (prev_cmd && prev_cmd->TextureId == curr_texture_id && memcmp(&prev_cmd->ClipRect, &GetCurrentClipRect(), sizeof(ImVec4)) == 0 && prev_cmd->UserCallback == NULL)
+    if (curr_cmd->ElemCount == 0 && prev_cmd && prev_cmd->TextureId == curr_texture_id && memcmp(&prev_cmd->ClipRect, &GetCurrentClipRect(), sizeof(ImVec4)) == 0 && prev_cmd->UserCallback == NULL)
         CmdBuffer.pop_back();
     else
         curr_cmd->TextureId = curr_texture_id;
@@ -341,7 +341,7 @@ void ImDrawList::ChannelsMerge()
         if (int sz = ch.CmdBuffer.Size) { memcpy(cmd_write, ch.CmdBuffer.Data, sz * sizeof(ImDrawCmd)); cmd_write += sz; }
         if (int sz = ch.IdxBuffer.Size) { memcpy(_IdxWritePtr, ch.IdxBuffer.Data, sz * sizeof(ImDrawIdx)); _IdxWritePtr += sz; }
     }
-    AddDrawCmd();
+    UpdateClipRect(); // We call this instead of AddDrawCmd(), so that empty channels won't produce an extra draw call.
     _ChannelsCount = 1;
 }