bounding box issue with pdf and svg export

When I export a graph in pdf or svg, with node labels shown, the node labels do not seem to be taken into account when the image size is defined ; there are often node labels that are cut by the border of the image.
In svg, this is less an issue, since I can still recover the whole label with an editor.

I've attached an example: I've created a graph with two nodes, on having a long label ("supercalifragilisticexpialidocious") that doesn't appear in the pdf export.