[BUG] Calling partition() on an empty Table leads to a crash

[firestarman]

Test to reproduce this bug.

  @Test
  void testPartitionEmptyTable() {
    try (Table t = new Table.TestBuilder()
        .timestampDayColumn()
        .build();
         ColumnVector parts = ColumnVector
             .fromInts();
         PartitionedTable pt = t.partition(parts, 3)) {
      assertArrayEquals(new int[]{0, 0, 0}, pt.getPartitions());
    }
  }

After building the libcudf, run the test as the follows

cd <path-to-cudf-root>/java
mvn test -Dtest=ai.rapids.cudf.TableTest#testPartitionEmptyTable

Crash stack

Stack: [0x00007f5e1e0c9000,0x00007f5e1e1c9000],  sp=0x00007f5e1e1c5868,  free space=1010k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
C  [libc.so.6+0x18b805]

Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
j  ai.rapids.cudf.Table.partition(JJI[I)[J+0
j  ai.rapids.cudf.Table.partition(Lai/rapids/cudf/ColumnView;I)Lai/rapids/cudf/PartitionedTable;+23
j  ai.rapids.cudf.TableTest.testPartitionEmptyTable()V+33
v  ~StubRoutines::call_stub
j  sun.reflect.NativeMethodAccessorImpl.invoke0(Ljava/lang/reflect/Method;Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+0
j  sun.reflect.NativeMethodAccessorImpl.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+100
j  sun.reflect.DelegatingMethodAccessorImpl.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+6
j  java.lang.reflect.Method.invoke(Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+56
j  org.junit.platform.commons.util.ReflectionUtils.invokeMethod(Ljava/lang/reflect/Method;Ljava/lang/Object;[Ljava/lang/Object;)Ljava/lang/Object;+41
j  org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(Ljava/lang/reflect/Method;Ljava/lang/Object;Lorg/junit/jupiter/api/extension/ExtensionContext;Lorg/junit/jupiter/engine/extension/ExtensionRegistry;)Ljava/lang/Object;+32
j  org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$7(Lorg/junit/jupiter/api/extension/ExtensionContext;Lorg/junit/jupiter/engine/execution/JupiterEngineExecutionContext;)V+24
j  org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor$$Lambda$221.execute()V+12
j  org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(Lorg/junit/platform/engine/support/hierarchical/ThrowableCollector$Executable;)V+1
j  org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(Lorg/junit/jupiter/engine/execution/JupiterEngineExecutionContext;Lorg/junit/platform/engine/support/hierarchical/Node$DynamicTestExecutor;)V+21
j  org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(Lorg/junit/jupiter/engine/execution/JupiterEngineExecutionContext;Lorg/junit/platform/engine/support/hierarchical/Node$DynamicTestExecutor;)Lorg/junit/jupiter/engine/execution/JupiterEngineExecutionContext;+44

[UPDATES]
The crash happened at line #2644 . When row number is 0 (aka an empty table), the size of partition_offsets is 0, then partition_offsets.end() - 1 points to an invalid address. But according to the partition's doc, the size of partition_offsets should be num_partitions + 1.

[firestarman]

The crash happened at line #2644 . When row number is 0 (aka an empty table), the size of partition_offsets is 0, then partition_offsets.end() - 1 points to an invalid address.