cwensel/cascading — pull request #10 by vbehar (2012-10-03 09:49:28+00:00)
Title: add a check on FileInputFormat.setInputPaths

if we use InputFormat classes that don't use the filesystem, and thus don't set "mapred.input.dir", we end up with :
```
Exception in thread "main" cascading.flow.planner.PlannerException: could not build flow from assembly: [0]
at cascading.flow.planner.FlowPlanner.handleExceptionDuringPlanning(FlowPlanner.java:515)
at cascading.flow.hadoop.planner.HadoopPlanner.buildFlow(HadoopPlanner.java:230)
at cascading.flow.FlowConnector.connect(FlowConnector.java:454)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 0
at org.apache.hadoop.mapred.FileInputFormat.setInputPaths(FileInputFormat.java:318)
at cascading.tap.hadoop.io.MultiInputFormat.addInputFormat(MultiInputFormat.java:76)
at cascading.flow.hadoop.HadoopFlowStep.initFromSources(HadoopFlowStep.java:345)
at cascading.flow.hadoop.HadoopFlowStep.getInitializedConfig(HadoopFlowStep.java:98)
at cascading.flow.hadoop.HadoopFlowStep.createFlowStepJob(HadoopFlowStep.java:200)
at cascading.flow.hadoop.HadoopFlowStep.createFlowStepJob(HadoopFlowStep.java:68)
at cascading.flow.planner.BaseFlowStep.getFlowStepJob(BaseFlowStep.java:588)
at cascading.flow.BaseFlow.initializeNewJobsMap(BaseFlow.java:1162)
at cascading.flow.BaseFlow.initialize(BaseFlow.java:184)
at cascading.flow.hadoop.planner.HadoopPlanner.buildFlow(HadoopPlanner.java:224)
```

So the MultiInputFormat should not try to set an empty array of paths on FileInputFormat.