TreeNode: Fixed bug where dragging a payload over a TreeNode() with either _OpenOnDoubleClick or _OpenOnArrow would open the node. (#143)

imgui_internal.h

@@ -1165,6 +1165,7 @@ struct ImGuiContext
     ImGuiID                 DragDropAcceptIdCurr;               // Target item id (set at the time of accepting the payload)
     ImGuiID                 DragDropAcceptIdPrev;               // Target item id from previous frame (we need to store this to allow for overlapping drag and drop targets)
     int                     DragDropAcceptFrameCount;           // Last time a target expressed a desire to accept the source
+    ImGuiID                 DragDropHoldJustPressedId;          // Set when holding a payload just made ButtonBehavior() return a press.
     ImVector<unsigned char> DragDropPayloadBufHeap;             // We don't expose the ImVector<> directly, ImGuiPayload only holds pointer+size
     unsigned char           DragDropPayloadBufLocal[16];        // Local buffer for small payloads
 
@@ -1320,6 +1321,7 @@ struct ImGuiContext
         DragDropAcceptIdCurrRectSurface = 0.0f;
         DragDropAcceptIdPrev = DragDropAcceptIdCurr = 0;
         DragDropAcceptFrameCount = -1;
+        DragDropHoldJustPressedId = 0;
         memset(DragDropPayloadBufLocal, 0, sizeof(DragDropPayloadBufLocal));
 
         CurrentTabBar = NULL;