Make tfs_true_false the default for booleans

Instead of adding a TFS(&tfs_true_false) to every boolean
field, make it the default if "strings" is NULL.

This seems to match the already existing documentation:

    If the Boolean field is to be displayed as "False" or "True", the
    'strings' field would be set to NULL.

1 files changed, 21 insertions, 0 deletions

diff --git a/test/suite_dfilter/group_syntax.py b/test/suite_dfilter/group_syntax.py
index 70ea9fb73c..4f6afc03dd 100644
--- a/test/suite_dfilter/group_syntax.py
+++ b/test/suite_dfilter/group_syntax.py
@@ -437,5 +437,26 @@ class TestDfilterTFSValueString:
     trace_file = "http.pcap"
 
     def test_tfs_1(self, checkDFilterCount):
+        dfilter = 'ip.flags.df == True'
+        checkDFilterCount(dfilter, 1)
+
+    def test_tfs_2(self, checkDFilterCount):
+        dfilter = 'ip.flags.df == "True"'
+        checkDFilterCount(dfilter, 1)
+
+    def test_tfs_3(self, checkDFilterCount):
         dfilter = 'ip.flags.df == "Set"'
         checkDFilterCount(dfilter, 1)
+
+    def test_tfs_4(self, checkDFilterCount):
+        dfilter = 'frame.ignored == False'
+        checkDFilterCount(dfilter, 1)
+
+    def test_tfs_5(self, checkDFilterCount):
+        dfilter = 'frame.ignored == "False"'
+        checkDFilterCount(dfilter, 1)
+
+    def test_tfs_6(self, checkDFilterFail):
+        error = 'expected "True" or "False", not "Unset"'
+        dfilter = 'frame.ignored == "Unset"'
+        checkDFilterFail(dfilter, error)