Removed the bizarre legacy default argument for 'TreePush(const void* ptr = NULL)' (#1057)

Followup to e605f2179
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index d9f43db..f0ce26a 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -60,7 +60,9 @@
      - requires an explicit identifier. You may still use e.g. PushID() calls and then pass an empty identifier.
      - always uses style.FramePadding for padding, to be consistent with other buttons. You may use PushStyleVar() to alter this.
    - As always we are keeping a redirection function available (will obsolete later).
-- Commented out redirecting functions/enums names that were marked obsolete in 1.77 and 1.78 (June 2020): (#3361)
+ - Removed the bizarre legacy default argument for 'TreePush(const void* ptr = NULL)'. (#1057)
+   Must always pass a pointer value explicitly, NULL is ok.
+ - Commented out redirecting functions/enums names that were marked obsolete in 1.77 and 1.78 (June 2020): (#3361)
    - DragScalar(), DragScalarN(), DragFloat(), DragFloat2(), DragFloat3(), DragFloat4()
    - SliderScalar(), SliderScalarN(), SliderFloat(), SliderFloat2(), SliderFloat3(), SliderFloat4()
      - For old signatures ending with (..., const char* format, float power = 1.0f) -> use (..., format ImGuiSliderFlags_Logarithmic) if power != 1.0f.
diff --git a/imgui.cpp b/imgui.cpp
index cad2b62..21fc1cc 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -384,6 +384,7 @@
  When you are not sure about an old symbol or function name, try using the Search/Find function of your IDE to look for comments or references in all imgui files.
  You can read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2022/09/12 (1.89) - removed the bizarre legacy default argument for 'TreePush(const void* ptr = NULL)', always pass a pointer value explicitly, NULL is ok.
  - 2022/09/05 (1.89) - commented out redirecting functions/enums names that were marked obsolete in 1.77 and 1.78 (June 2020):
                          - DragScalar(), DragScalarN(), DragFloat(), DragFloat2(), DragFloat3(), DragFloat4(): For old signatures ending with (..., const char* format, float power = 1.0f) -> use (..., format ImGuiSliderFlags_Logarithmic) if power != 1.0f.
                          - SliderScalar(), SliderScalarN(), SliderFloat(), SliderFloat2(), SliderFloat3(), SliderFloat4(): For old signatures ending with (..., const char* format, float power = 1.0f) -> use (..., format ImGuiSliderFlags_Logarithmic) if power != 1.0f.
diff --git a/imgui.h b/imgui.h
index df712f0..de75cb1 100644
--- a/imgui.h
+++ b/imgui.h
@@ -65,7 +65,7 @@
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
 #define IMGUI_VERSION               "1.89 WIP"
-#define IMGUI_VERSION_NUM           18818
+#define IMGUI_VERSION_NUM           18819
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 
@@ -602,7 +602,7 @@
     IMGUI_API bool          TreeNodeExV(const char* str_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
     IMGUI_API bool          TreeNodeExV(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
     IMGUI_API void          TreePush(const char* str_id);                                       // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call TreePush/TreePop yourself if desired.
-    IMGUI_API void          TreePush(const void* ptr_id = NULL);                                // "
+    IMGUI_API void          TreePush(const void* ptr_id);                                       // "
     IMGUI_API void          TreePop();                                                          // ~ Unindent()+PopId()
     IMGUI_API float         GetTreeNodeToLabelSpacing();                                        // horizontal distance preceding label when using TreeNode*() or Bullet() == (g.FontSize + style.FramePadding.x*2) for a regular unframed TreeNode
     IMGUI_API bool          CollapsingHeader(const char* label, ImGuiTreeNodeFlags flags = 0);  // if returning 'true' the header is open. doesn't indent nor push on ID stack. user doesn't have to call TreePop().