[3373] Python config element merge method now does proper deep merge

The merge function defined in isc.cc.data module did not correctly
do deep merges, so map sub elements were simply be replaced rather
than merged.

src/lib/python/isc/cc/data.py

@@ -51,14 +51,26 @@ def remove_identical(a, b):
         del(a[id])
 
 def merge(orig, new):
-    """Merges the contents of new into orig, think recursive update()
-       orig and new must both be dicts. If an element value is None in
-       new it will be removed in orig."""
+    """Merges the contents of new into orig. If the element is dict
+       orig and then it goes recursive to merge the maps.
+       If an element value is None in new it will be removed in orig.
+       Previously this method was relying on dict.update but this does
+       not do deep merges in the manner required."""
     if type(orig) != dict or type(new) != dict:
         raise DataTypeError("Not a dict in merge()")
-    orig.update(new)
+
+    for key in new.keys():
+        if (key in orig):
+            if (type(orig[key]) == dict):
+                merge(orig[key], new[key])
+            else:
+                orig[key] = new[key]
+        else:
+            orig[key] = new[key]
+
     remove_null_items(orig)
 
+
 def remove_null_items(d):
     """Recursively removes all (key,value) pairs from d where the
        value is None"""

src/lib/python/isc/cc/tests/data_test.py

@@ -34,37 +34,37 @@ class TestData(unittest.TestCase):
         c = {}
         data.remove_identical(a, b)
         self.assertEqual(a, c)
-    
+
         a = { "a": 1, "b": [ 1, 2 ] }
         b = {}
         c = { "a": 1, "b": [ 1, 2 ] }
         data.remove_identical(a, b)
         self.assertEqual(a, c)
-    
+
         a = { "a": 1, "b": [ 1, 2 ] }
         b = { "a": 1, "b": [ 1, 2 ] }
         c = {}
         data.remove_identical(a, b)
         self.assertEqual(a, c)
-    
+
         a = { "a": 1, "b": [ 1, 2 ] }
         b = { "a": 1, "b": [ 1, 3 ] }
         c = { "b": [ 1, 2 ] }
         data.remove_identical(a, b)
         self.assertEqual(a, c)
-    
+
         a = { "a": { "b": "c" } }
         b = {}
         c = { "a": { "b": "c" } }
         data.remove_identical(a, b)
         self.assertEqual(a, c)
-    
+
         a = { "a": { "b": "c" } }
         b = { "a": { "b": "c" } }
         c = {}
         data.remove_identical(a, b)
         self.assertEqual(a, c)
-    
+
         a = { "a": { "b": "c" } }
         b = { "a": { "b": "d" } }
         c = { "a": { "b": "c" } }
@@ -75,7 +75,7 @@ class TestData(unittest.TestCase):
                           a, 1)
         self.assertRaises(data.DataTypeError, data.remove_identical,
                           1, b)
-        
+
     def test_merge(self):
         d1 = { 'a': 'a', 'b': 1, 'c': { 'd': 'd', 'e': 2 } }
         d2 = { 'a': None, 'c': { 'd': None, 'e': 3, 'f': [ 1 ] } }
@@ -87,6 +87,13 @@ class TestData(unittest.TestCase):
         self.assertRaises(data.DataTypeError, data.merge, 1, d2)
         self.assertRaises(data.DataTypeError, data.merge, None, None)
 
+        # An example that failed when merge was relying on dict.update.
+        tnew = {'d2': {'port': 54000}}
+        torig = {'ifaces': ['p8p1'], 'db': {'type': 'memfile'}, 'd2': {'ip': '127.0.0.1', 'enable': True}}
+        tchk = {'ifaces': ['p8p1'], 'db': {'type': 'memfile'}, 'd2': {'ip': '127.0.0.1', 'enable': True, 'port': 54000}}
+        tmrg = torig
+        data.merge(tmrg, tnew)
+        self.assertEqual(tmrg, tchk)
 
     def test_split_identifier_list_indices(self):
         id, indices = data.split_identifier_list_indices('a')
@@ -103,15 +110,15 @@ class TestData(unittest.TestCase):
         id, indices = data.split_identifier_list_indices('a/b/c')
         self.assertEqual(id, 'a/b/c')
         self.assertEqual(indices, None)
-        
+
         id, indices = data.split_identifier_list_indices('a/b/c[1]')
         self.assertEqual(id, 'a/b/c')
         self.assertEqual(indices, [1])
-       
+
         id, indices = data.split_identifier_list_indices('a/b/c[1][2][3]')
         self.assertEqual(id, 'a/b/c')
         self.assertEqual(indices, [1, 2, 3])
-        
+
         id, indices = data.split_identifier_list_indices('a[0]/b[1]/c[2]')
         self.assertEqual(id, 'a[0]/b[1]/c')
         self.assertEqual(indices, [2])
@@ -124,7 +131,7 @@ class TestData(unittest.TestCase):
         self.assertRaises(data.DataTypeError, data.split_identifier_list_indices, 'a[0]a[1]')
 
         self.assertRaises(data.DataTypeError, data.split_identifier_list_indices, 1)
-        
+
 
     def test_find(self):
         d1 = { 'a': 'a', 'b': 1, 'c': { 'd': 'd', 'e': 2, 'more': { 'data': 'here' } } }
@@ -151,7 +158,7 @@ class TestData(unittest.TestCase):
         d3 = { 'a': [ { 'b': [ {}, { 'c': 'd' } ] } ] }
         self.assertEqual(data.find(d3, 'a[0]/b[1]/c'), 'd')
         self.assertRaises(data.DataNotFoundError, data.find, d3, 'a[1]/b[1]/c')
-        
+
     def test_set(self):
         d1 = { 'a': 'a', 'b': 1, 'c': { 'd': 'd', 'e': 2 } }
         d12 = { 'b': 1, 'c': { 'e': 3, 'f': [ 1 ] } }
@@ -170,7 +177,7 @@ class TestData(unittest.TestCase):
         self.assertEqual(d1, d14)
         data.set(d1, 'c/f[0]/g[1]', 3)
         self.assertEqual(d1, d15)
-        
+
         self.assertRaises(data.DataTypeError, data.set, d1, 1, 2)
         self.assertRaises(data.DataTypeError, data.set, 1, "", 2)
         self.assertRaises(data.DataTypeError, data.set, d1, 'c[1]', 2)
@@ -205,7 +212,7 @@ class TestData(unittest.TestCase):
         self.assertEqual(d3, { 'a': [ [ 1, 3 ] ] })
         data.unset(d3, 'a[0][1]')
         self.assertEqual(d3, { 'a': [ [ 1 ] ] })
-        
+
     def test_find_no_exc(self):
         d1 = { 'a': 'a', 'b': 1, 'c': { 'd': 'd', 'e': 2, 'more': { 'data': 'here' } } }
         self.assertEqual(data.find_no_exc(d1, ''), d1)
@@ -220,7 +227,7 @@ class TestData(unittest.TestCase):
         self.assertEqual(data.find_no_exc(None, 1), None)
         self.assertEqual(data.find_no_exc("123", ""), "123")
         self.assertEqual(data.find_no_exc("123", ""), "123")
-        
+
     def test_parse_value_str(self):
         self.assertEqual(data.parse_value_str("1"), 1)
         self.assertEqual(data.parse_value_str("true"), True)