Improve Pydoc interactive browsing (#2001). Patch by Ron Adam.

* A -b option to start an enhanced browsing session.
* Allow -b and -p options to be used together.
* Specifying port 0 will pick an arbitrary unused socket port.
* A new browse() function to start the new server and browser.
* Show Python version information in the header.
* A *Get* field which takes the same input as the help() function.
* A *Search* field which replaces the Tkinter search box.
* Links to *Module Index*, *Topics*, and *Keywords*.
* Improved source file viewing.
* An HTMLDoc.filelink() method.
* The -g option and the gui() and serve() functions are deprecated.

Lib/test/test_pydoc.py

@@ -1,13 +1,14 @@
-import sys
 import os
-import os.path
+import sys
 import difflib
-import subprocess
-import re
-import pydoc
 import inspect
-import unittest
+import pydoc
+import re
+import string
+import subprocess
 import test.support
+import time
+import unittest
 import xml.etree
 import textwrap
 from io import StringIO
@@ -221,19 +222,25 @@ def get_pydoc_text(module):
 
     output = doc.docmodule(module)
 
-    # cleanup the extra text formatting that pydoc preforms
+    # clean up the extra text formatting that pydoc performs
     patt = re.compile('\b.')
     output = patt.sub('', output)
     return output.strip(), loc
 
 def print_diffs(text1, text2):
     "Prints unified diffs for two texts"
+    # XXX now obsolete, use unittest built-in support
     lines1 = text1.splitlines(True)
     lines2 = text2.splitlines(True)
     diffs = difflib.unified_diff(lines1, lines2, n=0, fromfile='expected',
                                  tofile='got')
     print('\n' + ''.join(diffs))
 
+def get_html_title(text):
+    _, _, text = text.rpartition("<title>")
+    title, _, _ = text.rpartition("</title>")
+    return title
+
 
 class PyDocDocTest(unittest.TestCase):
 
@@ -373,16 +380,8 @@ class TestDescriptions(unittest.TestCase):
         doc = pydoc.render_doc(pydocfodder)
         self.assertIn("pydocfodder", doc)
 
-    def test_classic_class(self):
-        class C: "Classic class"
-        c = C()
-        self.assertEqual(pydoc.describe(C), 'class C')
-        self.assertEqual(pydoc.describe(c), 'C')
-        expected = 'C in module %s' % __name__
-        self.assertIn(expected, pydoc.render_doc(c))
-
     def test_class(self):
-        class C(object): "New-style class"
+        class C: "New-style class"
         c = C()
 
         self.assertEqual(pydoc.describe(C), 'class C')
@@ -391,8 +390,78 @@ class TestDescriptions(unittest.TestCase):
         self.assertIn(expected, pydoc.render_doc(c))
 
 
+class PyDocServerTest(unittest.TestCase):
+    """Tests for pydoc._start_server"""
+
+    def test_server(self):
+
+        # Minimal test that starts the server, then stops it.
+        def my_url_handler(url, content_type):
+            text = 'the URL sent was: (%s, %s)' % (url, content_type)
+            return text
+
+        serverthread = pydoc._start_server(my_url_handler, port=0)
+        starttime = time.time()
+        timeout = 1  #seconds
+
+        while serverthread.serving:
+            time.sleep(.01)
+            if serverthread.serving and time.time() - starttime > timeout:
+                serverthread.stop()
+                break
+
+        self.assertEqual(serverthread.error, None)
+
+
+class PyDocUrlHandlerTest(unittest.TestCase):
+    """Tests for pydoc._url_handler"""
+
+    def test_content_type_err(self):
+        err = 'Error: unknown content type '
+        f = pydoc._url_handler
+        result = f("", "")
+        self.assertEqual(result, err + "''")
+        result = f("", "foobar")
+        self.assertEqual(result, err + "'foobar'")
+
+    def test_url_requests(self):
+        # Test for the correct title in the html pages returned.
+        # This tests the different parts of the URL handler without
+        # getting too picky about the exact html.
+        requests = [
+            ("", "Python: Index of Modules"),
+            ("get?key=", "Python: Index of Modules"),
+            ("index", "Python: Index of Modules"),
+            ("topics", "Python: Topics"),
+            ("keywords", "Python: Keywords"),
+            ("pydoc", "Python: module pydoc"),
+            ("get?key=pydoc", "Python: module pydoc"),
+            ("search?key=pydoc", "Python: Search Results"),
+            ("def", "Python: KEYWORD def"),
+            ("STRINGS", "Python: TOPIC STRINGS"),
+            ("foobar", "Python: Error"),
+            ("getfile?key=foobar", "Python: Read Error"),
+            ]
+
+        for url, title in requests:
+            text = pydoc._url_handler(url, "text/html")
+            result = get_html_title(text)
+            self.assertEqual(result, title)
+
+        path = string.__file__
+        title = "Python: getfile /" + path
+        url = "getfile?key=" + path
+        text = pydoc._url_handler(url, "text/html")
+        result = get_html_title(text)
+        self.assertEqual(result, title)
+
+
 def test_main():
-    test.support.run_unittest(PyDocDocTest, TestDescriptions)
+    test.support.run_unittest(PyDocDocTest,
+                              TestDescriptions,
+                              PyDocServerTest,
+                              PyDocUrlHandlerTest,
+                              )
 
 if __name__ == "__main__":
     test_main()