From edb5cffdb20ad959c80b665cb8c2589f4c71414d Mon Sep 17 00:00:00 2001 From: jhendersonHDF Date: Fri, 27 Oct 2023 23:20:29 -0500 Subject: Avoid attempted use of NULL pointer in parallel compression code (#3786) The parallel compression test code tests for the case where all MPI ranks have no selection in a dataset when writing to it. Add an early exit to the code to avoid attempting to use a NULL pointer due to there being no work to do. --- src/H5Dmpio.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/H5Dmpio.c b/src/H5Dmpio.c index 16243fa..b40ab4b 100644 --- a/src/H5Dmpio.c +++ b/src/H5Dmpio.c @@ -3782,6 +3782,10 @@ H5D__mpio_redistribute_shared_chunks_int(H5D_filtered_collective_io_info_t *chun counts_disps_array = H5MM_xfree(counts_disps_array); } + /* No useful work to do - exit */ + if (coll_chunk_list_num_entries == 0) + HGOTO_DONE(SUCCEED); + /* * Phase 2 - Involved ranks now redistribute any shared chunks to new * owners as necessary. -- cgit v0.12