diff --git a/Lib/doctest.py b/Lib/doctest.py
index 6244fae..70c355a 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -236,6 +236,15 @@
     else:
         raise TypeError("Expected a module, string, or None")
 
+def _load_testfile(filename, package, module_relative):
+    if module_relative:
+        package = _normalize_module(package, 3)
+        filename = _module_relative_path(package, filename)
+        if hasattr(package, '__loader__'):
+            if hasattr(package.__loader__, 'get_data'):
+                return package.__loader__.get_data(filename), filename
+    return open(filename).read(), filename
+
 def _indent(s, indent=4):
     """
     Add the given number of space characters to the beginning every
@@ -1319,13 +1328,13 @@
     __LINECACHE_FILENAME_RE = re.compile(r'<doctest '
                                          r'(?P<name>[\w\.]+)'
                                          r'\[(?P<examplenum>\d+)\]>$')
-    def __patched_linecache_getlines(self, filename):
+    def __patched_linecache_getlines(self, filename, module_globals=None):
         m = self.__LINECACHE_FILENAME_RE.match(filename)
         if m and m.group('name') == self.test.name:
             example = self.test.examples[int(m.group('examplenum'))]
             return example.source.splitlines(True)
         else:
-            return self.save_linecache_getlines(filename)
+            return self.save_linecache_getlines(filename, module_globals)
 
     def run(self, test, compileflags=None, out=None, clear_globs=True):
         """
@@ -1933,9 +1942,7 @@
                          "relative paths.")
 
     # Relativize the path
-    if module_relative:
-        package = _normalize_module(package)
-        filename = _module_relative_path(package, filename)
+    text, filename = _load_testfile(filename, package, module_relative)
 
     # If no name was given, then use the file's name.
     if name is None:
@@ -1955,8 +1962,7 @@
         runner = DocTestRunner(verbose=verbose, optionflags=optionflags)
 
     # Read the file, convert it to a test, and run it.
-    s = open(filename).read()
-    test = parser.get_doctest(s, globs, name, filename, 0)
+    test = parser.get_doctest(text, globs, name, filename, 0)
     runner.run(test)
 
     if report:
@@ -2336,15 +2342,13 @@
                          "relative paths.")
 
     # Relativize the path.
-    if module_relative:
-        package = _normalize_module(package)
-        path = _module_relative_path(package, path)
+    doc, path = _load_testfile(path, package, module_relative)
+
     if "__file__" not in globs:
         globs["__file__"] = path
 
     # Find the file and read it.
     name = os.path.basename(path)
-    doc = open(path).read()
 
     # Convert it to a test, and wrap it in a DocFileCase.
     test = parser.get_doctest(doc, globs, name, path, 0)
diff --git a/Lib/inspect.py b/Lib/inspect.py
index 57bf18c..af911e0 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -353,7 +353,7 @@
         if 'b' in mode and string.lower(filename[-len(suffix):]) == suffix:
             # Looks like a binary file.  We want to only return a text file.
             return None
-    if os.path.exists(filename):
+    if os.path.exists(filename) or hasattr(getmodule(object),'__loader__'):
         return filename
 
 def getabsfile(object):
@@ -379,7 +379,7 @@
     if file in modulesbyfile:
         return sys.modules.get(modulesbyfile[file])
     for module in sys.modules.values():
-        if hasattr(module, '__file__'):
+        if ismodule(module) and hasattr(module, '__file__'):
             modulesbyfile[
                 os.path.realpath(
                         getabsfile(module))] = module.__name__
@@ -406,7 +406,7 @@
     in the file and the line number indexes a line in that list.  An IOError
     is raised if the source code cannot be retrieved."""
     file = getsourcefile(object) or getfile(object)
-    lines = linecache.getlines(file)
+    lines = linecache.getlines(file, getmodule(object).__dict__)
     if not lines:
         raise IOError('could not get source code')
 
diff --git a/Lib/linecache.py b/Lib/linecache.py
index 2ccc6c6..696e189 100644
--- a/Lib/linecache.py
+++ b/Lib/linecache.py
@@ -10,8 +10,8 @@
 
 __all__ = ["getline", "clearcache", "checkcache"]
 
-def getline(filename, lineno):
-    lines = getlines(filename)
+def getline(filename, lineno, module_globals=None):
+    lines = getlines(filename, module_globals)
     if 1 <= lineno <= len(lines):
         return lines[lineno-1]
     else:
@@ -30,14 +30,14 @@
     cache = {}
 
 
-def getlines(filename):
+def getlines(filename, module_globals=None):
     """Get the lines for a file from the cache.
     Update the cache if it doesn't contain an entry for this file already."""
 
     if filename in cache:
         return cache[filename][2]
     else:
-        return updatecache(filename)
+        return updatecache(filename,module_globals)
 
 
 def checkcache(filename=None):
@@ -54,6 +54,8 @@
 
     for filename in filenames:
         size, mtime, lines, fullname = cache[filename]
+        if mtime is None:
+            continue   # no-op for files loaded via a __loader__
         try:
             stat = os.stat(fullname)
         except os.error:
@@ -63,7 +65,7 @@
             del cache[filename]
 
 
-def updatecache(filename):
+def updatecache(filename, module_globals=None):
     """Update a cache entry and return its list of lines.
     If something's wrong, print a message, discard the cache entry,
     and return an empty list."""
@@ -72,12 +74,34 @@
         del cache[filename]
     if not filename or filename[0] + filename[-1] == '<>':
         return []
+
     fullname = filename
     try:
         stat = os.stat(fullname)
     except os.error, msg:
-        # Try looking through the module search path.
         basename = os.path.split(filename)[1]
+
+        # Try for a __loader__, if available        
+        if module_globals and '__loader__' in module_globals:
+            name = module_globals.get('__name__')
+            loader = module_globals['__loader__']
+            get_source = getattr(loader, 'get_source' ,None)
+
+            if name and get_source:
+                if basename.startswith(name.split('.')[-1]+'.'):
+                    try:
+                        data = get_source(name)
+                    except (ImportError,IOError):
+                        pass
+                    else:
+                        cache[filename] = (
+                            len(data), None, 
+                            [line+'\n' for line in data.splitlines()], fullname
+                        )
+                        return cache[filename][2]
+
+        # Try looking through the module search path.
+
         for dirname in sys.path:
             # When using imputil, sys.path may contain things other than
             # strings; ignore them when it happens.
diff --git a/Lib/site.py b/Lib/site.py
index 6818e85..8074979 100644
--- a/Lib/site.py
+++ b/Lib/site.py
@@ -69,6 +69,8 @@
 def abs__file__():
     """Set all module' __file__ attribute to an absolute path"""
     for m in sys.modules.values():
+        if hasattr(m,'__loader__'):
+            continue   # don't mess with a PEP 302-supplied __file__
         try:
             m.__file__ = os.path.abspath(m.__file__)
         except AttributeError:
diff --git a/Lib/test/test_zipimport.py b/Lib/test/test_zipimport.py
index eb7cbf6..0d46f0b 100644
--- a/Lib/test/test_zipimport.py
+++ b/Lib/test/test_zipimport.py
@@ -12,7 +12,12 @@
 from test.test_importhooks import ImportHooksBaseTestCase, test_src, test_co
 
 import zipimport
-
+import linecache
+import doctest
+import inspect
+import StringIO
+from traceback import extract_tb, extract_stack, print_tb
+raise_src = 'def do_raise(): raise TypeError\n'
 
 # so we only run testAFakeZlib once if this test is run repeatedly
 # which happens when we look for ref leaks
@@ -54,7 +59,8 @@
 
     def setUp(self):
         # We're reusing the zip archive path, so we must clear the
-        # cached directory info.
+        # cached directory info and linecache
+        linecache.clearcache()
         zipimport._zip_directory_cache.clear()
         ImportHooksBaseTestCase.setUp(self)
 
@@ -83,6 +89,11 @@
 
             mod = __import__(".".join(modules), globals(), locals(),
                              ["__dummy__"])
+
+            call = kw.get('call')
+            if call is not None:
+                call(mod)
+
             if expected_ext:
                 file = mod.get_file()
                 self.assertEquals(file, os.path.join(TEMP_ZIP,
@@ -249,6 +260,74 @@
         self.doTest(".py", files, TESTMOD,
                     stuff="Some Stuff"*31)
 
+    def assertModuleSource(self, module):
+        self.assertEqual(inspect.getsource(module), test_src)
+
+    def testGetSource(self):
+        files = {TESTMOD + ".py": (NOW, test_src)}
+        self.doTest(".py", files, TESTMOD, call=self.assertModuleSource)
+
+    def testGetCompiledSource(self):
+        pyc = make_pyc(compile(test_src, "<???>", "exec"), NOW)
+        files = {TESTMOD + ".py": (NOW, test_src), 
+                 TESTMOD + pyc_ext: (NOW, pyc)}
+        self.doTest(pyc_ext, files, TESTMOD, call=self.assertModuleSource)
+
+    def runDoctest(self, callback):
+        files = {TESTMOD + ".py": (NOW, test_src),
+                 "xyz.txt": (NOW, ">>> log.append(True)\n")}
+        self.doTest(".py", files, TESTMOD, call=callback)
+
+    def doDoctestFile(self, module):
+        log = []
+        old_master, doctest.master = doctest.master, None
+        try:
+            doctest.testfile(
+                'xyz.txt', package=module, module_relative=True,
+                globs=locals()
+            )
+        finally:
+            doctest.master = old_master
+        self.assertEqual(log,[True])
+
+    def testDoctestFile(self):
+        self.runDoctest(self.doDoctestFile)
+
+    def doDoctestSuite(self, module):
+        log = []
+        doctest.DocFileTest(
+            'xyz.txt', package=module, module_relative=True,
+            globs=locals()
+        ).run()
+        self.assertEqual(log,[True])
+
+    def testDoctestSuite(self):
+        self.runDoctest(self.doDoctestSuite)
+
+
+    def doTraceback(self, module):
+        try:
+            module.do_raise()
+        except:
+            tb = sys.exc_info()[2].tb_next
+            
+            f,lno,n,line = extract_tb(tb, 1)[0]
+            self.assertEqual(line, raise_src.strip())
+
+            f,lno,n,line = extract_stack(tb.tb_frame, 1)[0]
+            self.assertEqual(line, raise_src.strip())
+
+            s = StringIO.StringIO()
+            print_tb(tb, 1, s)
+            self.failUnless(s.getvalue().endswith(raise_src))
+        else:
+            raise AssertionError("This ought to be impossible")
+
+    def testTraceback(self):
+        files = {TESTMOD + ".py": (NOW, raise_src)}
+        self.doTest(None, files, TESTMOD, call=self.doTraceback)
+
+
 class CompressedZipImportTestCase(UncompressedZipImportTestCase):
     compression = ZIP_DEFLATED
 
diff --git a/Lib/traceback.py b/Lib/traceback.py
index 4047ca5..454eb1b 100644
--- a/Lib/traceback.py
+++ b/Lib/traceback.py
@@ -66,7 +66,7 @@
         _print(file,
                '  File "%s", line %d, in %s' % (filename,lineno,name))
         linecache.checkcache(filename)
-        line = linecache.getline(filename, lineno)
+        line = linecache.getline(filename, lineno, f.f_globals)
         if line: _print(file, '    ' + line.strip())
         tb = tb.tb_next
         n = n+1
@@ -98,7 +98,7 @@
         filename = co.co_filename
         name = co.co_name
         linecache.checkcache(filename)
-        line = linecache.getline(filename, lineno)
+        line = linecache.getline(filename, lineno, f.f_globals)
         if line: line = line.strip()
         else: line = None
         list.append((filename, lineno, name, line))
@@ -281,7 +281,7 @@
         filename = co.co_filename
         name = co.co_name
         linecache.checkcache(filename)
-        line = linecache.getline(filename, lineno)
+        line = linecache.getline(filename, lineno, f.f_globals)
         if line: line = line.strip()
         else: line = None
         list.append((filename, lineno, name, line))
diff --git a/Lib/warnings.py b/Lib/warnings.py
index e622b9a..bc0b818 100644
--- a/Lib/warnings.py
+++ b/Lib/warnings.py
@@ -58,10 +58,11 @@
         if not filename:
             filename = module
     registry = globals.setdefault("__warningregistry__", {})
-    warn_explicit(message, category, filename, lineno, module, registry)
+    warn_explicit(message, category, filename, lineno, module, registry,
+                  globals)
 
 def warn_explicit(message, category, filename, lineno,
-                  module=None, registry=None):
+                  module=None, registry=None, module_globals=None):
     if module is None:
         module = filename or "<unknown>"
         if module[-3:].lower() == ".py":
@@ -92,6 +93,11 @@
     if action == "ignore":
         registry[key] = 1
         return
+
+    # Prime the linecache for formatting, in case the
+    # "file" is actually in a zipfile or something.
+    linecache.getlines(filename, module_globals)
+
     if action == "error":
         raise message
     # Other actions