dfilter: Fix slice using range [:j]

Fixes:

$ dftest 'frame[:10] contains 0xff'
dftest: ":10" is not a valid range.

1 files changed, 28 insertions, 0 deletions

diff --git a/test/suite_dfilter/group_range_method.py b/test/suite_dfilter/group_range_method.py
index c8b3445894..1afe3336e2 100644
--- a/test/suite_dfilter/group_range_method.py
+++ b/test/suite_dfilter/group_range_method.py
@@ -46,3 +46,31 @@ class case_range(unittest.TestCase):
     def test_slice_func_1(self, checkDFilterSucceed):
         dfilter = "string(ipx.src.node)[3:2] == \"cc:dd\""
         checkDFilterSucceed(dfilter)
+
+    # [i:j]    i = start_offset, j = length
+    # [i-j]    i = start_offset, j = end_offset, inclusive.
+    # [i]      i = start_offset, length = 1
+    # [:j]     start_offset = 0, length = j
+    # [i:]     start_offset = i, end_offset = end_of_field
+
+    def test_slice_range_1(self, checkDFilterSucceed):
+        # :5 is a length
+        dfilter = "frame[5:5] == 11:22:33:44:55"
+        checkDFilterSucceed(dfilter)
+
+    def test_slice_range_2(self, checkDFilterSucceed):
+        # end offset is inclusive
+        dfilter = "frame[5-10] == 11:22:33:44:55:66"
+        checkDFilterSucceed(dfilter)
+
+    def test_slice_range_3(self, checkDFilterSucceed):
+        dfilter = "frame[5] == 11"
+        checkDFilterSucceed(dfilter)
+
+    def test_slice_range_4(self, checkDFilterSucceed):
+        dfilter = "frame[:20] contains be:ef"
+        checkDFilterSucceed(dfilter)
+
+    def test_slice_range_5(self, checkDFilterSucceed):
+        dfilter = "frame[20:] contains :12345678"
+        checkDFilterSucceed(dfilter)