I am frequently getting "NullPointerException" errors when saving files. I've gotten the error on three different computers, Windows XP and Ubuntu Linux. Version info from one of the systems is below:
Product Version: Gephi 0.8.1 beta 201202141941
Java: 1.7.0_03; Java HotSpot(TM) Server VM 22.1-b02
System: Windows XP version 5.1 running on x86; Cp1252; en_US (gephi)
User directory: C:\Documents and Settings\wellingtonc\Application Data.gephi\0.8.1\dev
Cache directory: C:\Documents and Settings\wellingtonc\Application Data.gephi\0.8.1\dev\var\cache
The error occurs after I have used filtering to identify a subset of a graph and then moved that subset to a new workspace. For example, see the following steps:
Create a new project,
Add three nodes; connect two of them.
Filter -> Topology -> Giant Component
Apply Filter (the node not connected to the others is hidden)
Select "Export filtered graph to a new workspace", in the filter menu.
Go to the new workspace, save the file, everything works.
Close the project. Re-open it, and it will no longer save (it gives the error above).
I can upload the files if others are unable to reproduce this.
These are two files, one showing the file before applying the filter and creating the new workspace from filtered values, the other showing the result after doing that. I can successfully save the first (pre-filter) file, but get the NullPointer exception when trying to save the second (post-filter) file. Files are in tarball to avoid creating two comments.
One workaround identified: instead of filtering and creating a new workspace from the filtered graph, within the filter window use the "select" option to select the desired nodes, right click any of them, and copy/move to a new workspace.
(I was the original poster on Launchpad)
I'm not able to reproduce this bug anymore with the master branch. Closing the issue.