# Segfault in planar_layout if called on a graph with removed vertex

In `graph_tool-2.43`

, attempting to draw a graph with removed vertex leads to a SEGFAULT if the `planar_layout`

is used.

```
from graph_tool import Graph
from graph_tool.draw import (graph_draw, planar_layout)
g=Graph(directed=True)
v1=g.add_vertex()
v2=g.add_vertex()
v3=g.add_vertex()
v4=g.add_vertex()
g.add_edge(v1,v2)
g.add_edge(v2,v3)
g.add_edge(v1,v3)
g.add_edge(v1,v4)
g.remove_vertex(v3)
# g.reindex_edges() # <-- uncomment to workaround
pos=planar_layout(g)
graph_draw(g,pos=pos)
```

Reindexing edges seems to fix the problem.

During the crash, the following line appears sometimes:

`free(): invalid next size (fast)`