vppinfra: improve test coverage

Bonus corner-case bugfix in bitmap.h, found during the exercise.
Issue dates from 2001 or thereabouts. Please review this specific
change carefully.

lcov_post: filter system include directories and generated files in
build-root

Type: improvement

Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: Iaa0b63e9dc571dfe3d992197ac49ba4d93403c61
diff --git a/test/test_bihash.py b/test/test_bihash.py
index ac8bab3..019929a 100644
--- a/test/test_bihash.py
+++ b/test/test_bihash.py
@@ -61,5 +61,11 @@
             self.logger.critical(error)
             self.assertNotIn('failed', error)
 
+        error = self.vapi.cli("test bihash nitems 10 nbuckets 1 ncycles 3" +
+                              "search 2 careful 1 verbose 2 non-random-keys")
+        if error:
+            self.logger.critical(error)
+            self.assertNotIn('failed', error)
+
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)