Make request.debug be backward-compatible with old Zope 2 code as

suggested by Florent in http://mail.zope.org/pipermail/zope-dev/2006-April/027424.html.

request.debug will resolve to a form variable for all code except
code that lies in a 'zope.*' package. Eventually, we should deprecate
form variable access through getattr. I'm leaving a big comment to remind
us of that.

lib/python/ZPublisher/HTTPRequest.py

@@ -13,7 +13,7 @@
 
 __version__='$Revision: 1.96 $'[11:-2]
 
-import re, sys, os, time, random, codecs
+import re, sys, os, time, random, codecs, inspect
 from types import StringType, UnicodeType
 from BaseRequest import BaseRequest
 from HTTPResponse import HTTPResponse
@@ -258,13 +258,13 @@ class HTTPRequest(BaseRequest):
         have_env=environ.has_key
         get_env=environ.get
         self.response=response
-        other=self.other={'RESPONSE': response,
-                          'debug': DebugFlags()}
+        other=self.other={'RESPONSE': response}
         self.form={}
         self.taintedform={}
         self.steps=[]
         self._steps=[]
         self._lazies={}
+        self._debug = DebugFlags()
 
 
         if environ.has_key('REMOTE_ADDR'):
@@ -1216,7 +1216,18 @@ class HTTPRequest(BaseRequest):
             raise KeyError, key
         return v
 
+    # Using the getattr protocol to retrieve form values and similar
+    # is discouraged and is likely to be deprecated in the future.
+    # request.get(key) or request[key] should be used instead
     def __getattr__(self, key, default=_marker, returnTaints=0):
+        # ugly hack to make request.debug work for Zope 3 code (the
+        # ZPT engine, to be exact) while retaining request.debug
+        # functionality for all other code
+        if key == 'debug':
+            lastframe = inspect.currentframe().f_back
+            if lastframe.f_globals['__name__'].startswith('zope.'):
+                return self._debug
+        
         v = self.get(key, default, returnTaints=returnTaints)
         if v is _marker:
             raise AttributeError, key

lib/python/ZPublisher/tests/testHTTPRequest.py

@@ -701,6 +701,45 @@ class RequestTests( unittest.TestCase ):
         f.seek(0)
         self.assertEqual(f.xreadlines(),f)
 
+    def testDebug(self):
+        TEST_ENVIRON = {
+            'REQUEST_METHOD': 'GET',
+            'SERVER_NAME': 'localhost',
+            'SERVER_PORT': '80',
+            }
+        from StringIO import StringIO
+        from ZPublisher.HTTPRequest import HTTPRequest
+        s = StringIO('')
+
+        # accessing request.debug from non-Zope3 code will raise an
+        # AttributeError
+        env = TEST_ENVIRON.copy()
+        request = HTTPRequest(s, env, None)
+        request.processInputs()
+        self.assertRaises(AttributeError, getattr, request, 'debug')
+
+        # or it will actually yield a 'debug' form variable if it
+        # exists
+        env = TEST_ENVIRON.copy()
+        env['QUERY_STRING'] = 'debug=1'
+        request = HTTPRequest(s, env, None)
+        request.processInputs()
+        self.assertEqual(request.debug, '1')
+
+        # if we access request.debug from a Zope 3 package, however,
+        # we will see the DebugFlags instance
+        def getDebug(request):
+            return request.debug
+        # make a forged copy of getDebug that looks as if its module
+        # was a Zope 3 package
+        z3globals = globals().copy()
+        z3globals['__name__'] = 'zope.apackage'
+        import new
+        getDebugFromZope3 = new.function(getDebug.func_code, z3globals)
+        from zope.publisher.base import DebugFlags
+        self.assertEqual(getDebug(request), '1')
+        self.assert_(isinstance(getDebugFromZope3(request), DebugFlags))
+
 def test_suite():
     suite = unittest.TestSuite()
     suite.addTest(unittest.makeSuite(AuthCredentialsTestsa, 'test'))