[gdb] Add empty range unit test for gdb::parallel_for_each

Add a unit test that verifies that we can call gdb::parallel_for_each with an
empty range.

Tested on x86_64-linux.

1 files changed, 8 insertions, 0 deletions

diff --git a/gdb/unittests/parallel-for-selftests.c b/gdb/unittests/parallel-for-selftests.c
index e0c07e5..8a86b43 100644
--- a/gdb/unittests/parallel-for-selftests.c
+++ b/gdb/unittests/parallel-for-selftests.c
@@ -60,6 +60,14 @@ test (int n_threads)
 
   SELF_CHECK (counter == NUMBER);
 
+  counter = 0;
+  gdb::parallel_for_each (1, 0, 0,
+			  [&] (int start, int end)
+			  {
+			    counter += end - start;
+			  });
+  SELF_CHECK (counter == 0);
+
 #undef NUMBER
 }