Docking: Fixed docking overlay bits appearing at (0,0), because of 43bd80a4. Most typically noticable when disabling multi-viewport.

imgui.cpp

@@ -11684,7 +11684,7 @@ struct ImGuiDockPreviewData
     float           SplitRatio;
     ImRect          DropRectsDraw[ImGuiDir_COUNT + 1];  // May be slightly different from hit-testing drop rects used in DockNodeCalcDropRects()
 
-    ImGuiDockPreviewData() : FutureNode(0) { IsDropAllowed = IsCenterAvailable = IsSidesAvailable = IsSplitDirExplicit = false; SplitNode = NULL; SplitDir = ImGuiDir_None; SplitRatio = 0.f; }
+    ImGuiDockPreviewData() : FutureNode(0) { IsDropAllowed = IsCenterAvailable = IsSidesAvailable = IsSplitDirExplicit = false; SplitNode = NULL; SplitDir = ImGuiDir_None; SplitRatio = 0.f; for (int n = 0; n < IM_ARRAYSIZE(DropRectsDraw); n++) DropRectsDraw[n] = ImRect(+FLT_MAX, +FLT_MAX, -FLT_MAX, -FLT_MAX); }
 };
 
 // Persistent Settings data, stored contiguously in SettingsNodes (sizeof() ~32 bytes)