Fixed SetWindowPos/SetNextWindowPos affectiving size computation (#175)

imgui.cpp

@@ -2915,7 +2915,7 @@ bool ImGui::Begin(const char* name, bool* p_opened, const ImVec2& size, float bg
     bool window_pos_set_by_api = false;
     if (g.SetNextWindowPosCond)
     {
-        const ImVec2 backup_cursor_pos = window->DC.CursorPos;
+        const ImVec2 backup_cursor_pos = window->DC.CursorPos;                  // FIXME: not sure of the exact reason of this anymore :( need to look into that.
         ImGui::SetWindowPos(g.SetNextWindowPosVal, g.SetNextWindowPosCond);
         window->DC.CursorPos = backup_cursor_pos;
         window_pos_set_by_api = true;
@@ -3706,7 +3706,8 @@ static void SetWindowPos(ImGuiWindow* window, const ImVec2& pos, ImGuiSetCond co
     const ImVec2 old_pos = window->Pos;
     window->PosFloat = pos;
     window->Pos = ImVec2((float)(int)window->PosFloat.x, (float)(int)window->PosFloat.y);
-    window->DC.CursorPos += (window->Pos - old_pos);  // As we happen to move the window while it is being appended to (which is a bad idea - will smear) let's at least offset the cursor
+    window->DC.CursorPos += (window->Pos - old_pos);    // As we happen to move the window while it is being appended to (which is a bad idea - will smear) let's at least offset the cursor
+    window->DC.CursorMaxPos += (window->Pos - old_pos); // And more importantly we need to adjust this so size calculation doesn't get affected.
 }
 
 void ImGui::SetWindowPos(const ImVec2& pos, ImGuiSetCond cond)