fix detection of "missing" existing values in CGI form parser [SF#1414149]

Author: Richard Jones

CHANGES.txt

@@ -32,6 +32,8 @@ Fixed:
 - enforce correct encoding of PostgreSQL backend (sf bug 1374235)
 - grouping/sorting on link to same class fixed (sf bug 1404930)
 - all backends implement the retired check in getnodeids (sf bug 1290560)
+- fix detection of "missing" existing values in CGI form parser (sf bug
+  1414149)
 
 
 2005-10-07 0.9.0b1

roundup/backends/back_metakit.py

@@ -1,4 +1,4 @@
-# $Id: back_metakit.py,v 1.101 2006-01-24 08:27:05 a1s Exp $
+# $Id: back_metakit.py,v 1.102 2006-01-25 02:24:28 richard Exp $
 '''Metakit backend for Roundup, originally by Gordon McMillan.
 
 Known Current Bugs:
@@ -82,6 +82,11 @@ def Database(config, journaltag=None):
     return db
 
 class _Database(hyperdb.Database, roundupdb.Database):
+    # Metakit has no concept of an explicit NULL
+    BACKEND_MISSING_STRING = ''
+    BACKEND_MISSING_NUMBER = 0
+    BACKEND_MISSING_BOOLEAN = 0
+
     def __init__(self, config, journaltag=None):
         self.config = config
         self.journaltag = journaltag

roundup/cgi/form_parser.py

@@ -463,15 +463,18 @@ def parse(self, create=0, num_re=re.compile('^\d+$')):
 
                 # "missing" existing values may not be None
                 if not existing:
-                    if isinstance(proptype, hyperdb.String) and not existing:
+                    if isinstance(proptype, hyperdb.String):
                         # some backends store "missing" Strings as empty strings
-                        existing = None
-                    elif isinstance(proptype, hyperdb.Number) and not existing:
+                        if existing == self.db.BACKEND_MISSING_STRING:
+                            existing = None
+                    elif isinstance(proptype, hyperdb.Number):
                         # some backends store "missing" Numbers as 0 :(
-                        existing = 0
-                    elif isinstance(proptype, hyperdb.Boolean) and not existing:
+                        if existing == self.db.BACKEND_MISSING_NUMBER:
+                            existing = None
+                    elif isinstance(proptype, hyperdb.Boolean):
                         # likewise Booleans
-                        existing = 0
+                        if existing == self.db.BACKEND_MISSING_BOOLEAN:
+                            existing = None
 
                 # if changed, set it
                 if value != existing:

roundup/hyperdb.py

@@ -15,7 +15,7 @@
 # BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
 # SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 #
-# $Id: hyperdb.py,v 1.114 2006-01-24 08:22:42 a1s Exp $
+# $Id: hyperdb.py,v 1.115 2006-01-25 02:24:28 richard Exp $
 
 """Hyperdatabase implementation, especially field types.
 """
@@ -271,6 +271,10 @@ class Database:
     # flag to set on retired entries
     RETIRED_FLAG = '__hyperdb_retired'
 
+    BACKEND_MISSING_STRING = None
+    BACKEND_MISSING_NUMBER = None
+    BACKEND_MISSING_BOOLEAN = None
+
     def __init__(self, config, journaltag=None):
         """Open a hyperdatabase given a specifier to some storage.
 

test/test_cgi.py

@@ -8,7 +8,7 @@
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 #
-# $Id: test_cgi.py,v 1.26 2004-11-18 16:23:58 a1s Exp $
+# $Id: test_cgi.py,v 1.27 2006-01-25 02:24:28 richard Exp $
 
 import unittest, os, shutil, errno, sys, difflib, cgi, re
 
@@ -424,15 +424,30 @@ def testInvalidNumber(self):
     def testSetNumber(self):
         self.assertEqual(self.parseForm({'number': '1'}),
             ({('test', None): {'number': 1}}, []))
+        self.assertEqual(self.parseForm({'number': '0'}),
+            ({('test', None): {'number': 0}}, []))
         self.assertEqual(self.parseForm({'number': '\n0\n'}),
             ({('test', None): {'number': 0}}, []))
+
+    def testSetNumberReplaceOne(self):
         nodeid = self.db.test.create(number=1)
         self.assertEqual(self.parseForm({'number': '1'}, 'test', nodeid),
             ({('test', nodeid): {}}, []))
+        self.assertEqual(self.parseForm({'number': '0'}, 'test', nodeid),
+            ({('test', nodeid): {'number': 0}}, []))
+
+    def testSetNumberReplaceZero(self):
         nodeid = self.db.test.create(number=0)
         self.assertEqual(self.parseForm({'number': '0'}, 'test', nodeid),
             ({('test', nodeid): {}}, []))
 
+    def testSetNumberReplaceNone(self):
+        nodeid = self.db.test.create()
+        self.assertEqual(self.parseForm({'number': '0'}, 'test', nodeid),
+            ({('test', nodeid): {'number': 0}}, []))
+        self.assertEqual(self.parseForm({'number': '1'}, 'test', nodeid),
+            ({('test', nodeid): {'number': 1}}, []))
+
     def testEmptyNumberSet(self):
         nodeid = self.db.test.create(number=0)
         self.assertEqual(self.parseForm({'number': ''}, 'test', nodeid),