Webots assertion when adding a RoadLine

[fabienrohrer]

Steps to Reproduce

1. Open projects/vehicles/worlds/city.wbt
2. Select the first "CurvedRoadSegment.lines" field
3. Click on the "Add node" button
4. Webots crashes with the stack above.

Additional context

Stack:

Application Specific Information:
Assertion failed: (acceptedNode), function doesFieldRestrictionAcceptNode, file nodes/utils/WbNodeUtilities.cpp, line 528.
 

Thread 0 Crashed:: CrBrowserMain  Dispatch queue: com.apple.main-thread
0   libsystem_kernel.dylib        	0x00007fff732cfb86 __pthread_kill + 10
1   libsystem_pthread.dylib       	0x00007fff73385c50 pthread_kill + 285
2   libsystem_c.dylib             	0x00007fff73239268 __abort + 144
3   libsystem_c.dylib             	0x00007fff732391d8 abort + 142
4   libsystem_c.dylib             	0x00007fff73201868 __assert_rtn + 320
5   com.cyberbotics.webots        	0x000000010ce3b24e (anonymous namespace)::doesFieldRestrictionAcceptNode(WbField const*, QString const&) + 398 (WbNodeUtilities.cpp:528)
6   com.cyberbotics.webots        	0x000000010ce3ab6e WbNodeUtilities::isAllowedToInsert(WbField const*, QString const&, WbNode const*, QString&, WbNode::NodeUse, QString, bool) + 126 (WbNodeUtilities.cpp:1410)
7   com.cyberbotics.webots        	0x000000010caaa5f8 WbAddNodeDialog::buildTree() + 1704 (WbAddNodeDialog.cpp:382)
8   com.cyberbotics.webots        	0x000000010caa96be WbAddNodeDialog::WbAddNodeDialog(WbNode*, WbField*, int, QWidget*) + 5294 (WbAddNodeDialog.cpp:158)
9   com.cyberbotics.webots        	0x000000010caac913 WbAddNodeDialog::WbAddNodeDialog(WbNode*, WbField*, int, QWidget*) + 51 (WbAddNodeDialog.cpp:163)
10  com.cyberbotics.webots        	0x000000010ccd3ede WbSceneTree::addNew() + 1374 (WbSceneTree.cpp:866)