From 20cc898cdd943a3a1d7628d88fd0c8ddbc450aaa Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sat, 25 Feb 2017 21:44:56 +0100
Subject: [PATCH 01/22] Support If-Modified-Since HTTP headers, return 304
 response if file was not modified

---
 Lib/http/server.py           | 18 ++++++++++++++++++
 Lib/test/test_httpservers.py | 14 ++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index 61ddecc7efe4e3..6c0ceef38e701b 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -100,6 +100,7 @@
 import socketserver
 import sys
 import time
+import datetime
 import urllib.parse
 import copy
 import argparse
@@ -687,6 +688,21 @@ def send_head(self):
             self.send_error(HTTPStatus.NOT_FOUND, "File not found")
             return None
         try:
+            # Use browser cache if possible
+            if "If-Modified-Since" in self.headers:
+                # compare If-Modified-Since and date of last file modification
+                fs = os.stat(path)
+                ims = email.utils.parsedate(self.headers["If-Modified-Since"])
+                if ims is not None:
+                    ims_datetime = datetime.datetime(*ims[:7])
+                    ims_dtstring = ims_datetime.strftime("%d %b %Y %H:%M:%S")
+                    last_modif = datetime.datetime.utcfromtimestamp(
+                        fs.st_mtime).strftime("%d %b %Y %H:%M:%S")
+                    if last_modif <= ims_dtstring:
+                        self.send_response(HTTPStatus.NOT_MODIFIED)
+                        self.end_headers()
+                        f.close()
+                        return
             self.send_response(HTTPStatus.OK)
             self.send_header("Content-type", ctype)
             fs = os.fstat(f.fileno())
@@ -1212,3 +1228,5 @@ def test(HandlerClass=BaseHTTPRequestHandler,
     else:
         handler_class = SimpleHTTPRequestHandler
     test(HandlerClass=handler_class, port=args.port, bind=args.bind)
+
+
diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index 5049538e664181..9a4326e6005678 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -444,6 +444,20 @@ def test_head(self):
         self.assertEqual(response.getheader('content-type'),
                          'application/octet-stream')
 
+    def test_browser_cache(self):
+        #constructs the path relative to the root directory of the HTTPServer
+        response = self.request(self.base_url + '/test')
+        self.check_status_and_reason(response, HTTPStatus.OK, data=self.data)
+        # get Last-Modified response heaer
+        last_modif = response.headers['Last-modified']
+        # send new request to the same url with request header 
+        # If-Modified-Since
+        from email.message import Message
+        headers = Message()
+        headers['If-Modified-Since'] = last_modif
+        response = self.request(self.base_url + '/test', headers=headers)
+        self.check_status_and_reason(response, HTTPStatus.NOT_MODIFIED)
+
     def test_invalid_requests(self):
         response = self.request('/', method='FOO')
         self.check_status_and_reason(response, HTTPStatus.NOT_IMPLEMENTED)

From f1d8a484dfa2812f57decb259f6bbcde72d59c05 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 09:53:42 +0100
Subject: [PATCH 02/22] Fix bug in datetime comparisons. Ignore
 If-Modified-Since if If-None-Match is present. Add tests.

---
 Lib/http/server.py           | 22 +++++++++++++---------
 Lib/test/test_httpservers.py | 30 ++++++++++++++++++++++++++++--
 2 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index 6c0ceef38e701b..ca1c5fdcab2507 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -687,25 +687,30 @@ def send_head(self):
         except OSError:
             self.send_error(HTTPStatus.NOT_FOUND, "File not found")
             return None
+
+        fs = os.fstat(f.fileno())
+            
         try:
             # Use browser cache if possible
-            if "If-Modified-Since" in self.headers:
+            if "If-Modified-Since" in self.headers \
+                    and not "If-None-Match" in self.headers:
                 # compare If-Modified-Since and date of last file modification
-                fs = os.stat(path)
                 ims = email.utils.parsedate(self.headers["If-Modified-Since"])
                 if ims is not None:
-                    ims_datetime = datetime.datetime(*ims[:7])
-                    ims_dtstring = ims_datetime.strftime("%d %b %Y %H:%M:%S")
-                    last_modif = datetime.datetime.utcfromtimestamp(
-                        fs.st_mtime).strftime("%d %b %Y %H:%M:%S")
-                    if last_modif <= ims_dtstring:
+                    # If-Modified-Since is UTC, rounded to the second
+                    tzinfo = datetime.timezone(datetime.timedelta(hours=0))
+                    ims_datetime = datetime.datetime(*ims[:7], tzinfo=tzinfo)
+                    # compare to UTC datetime of last modification, also 
+                    # rounded to the second
+                    mtime = int(fs.st_mtime)
+                    last_modif = datetime.datetime.fromtimestamp(mtime, tzinfo)
+                    if last_modif <= ims_datetime:
                         self.send_response(HTTPStatus.NOT_MODIFIED)
                         self.end_headers()
                         f.close()
                         return
             self.send_response(HTTPStatus.OK)
             self.send_header("Content-type", ctype)
-            fs = os.fstat(f.fileno())
             self.send_header("Content-Length", str(fs[6]))
             self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
             self.end_headers()
@@ -1229,4 +1234,3 @@ def test(HandlerClass=BaseHTTPRequestHandler,
         handler_class = SimpleHTTPRequestHandler
     test(HandlerClass=handler_class, port=args.port, bind=args.bind)
 
-
diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index 9a4326e6005678..0ed2f7578936ab 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -448,16 +448,42 @@ def test_browser_cache(self):
         #constructs the path relative to the root directory of the HTTPServer
         response = self.request(self.base_url + '/test')
         self.check_status_and_reason(response, HTTPStatus.OK, data=self.data)
-        # get Last-Modified response heaer
         last_modif = response.headers['Last-modified']
+
         # send new request to the same url with request header 
-        # If-Modified-Since
+        # If-Modified-Since set to Last-Modified : must return 304
         from email.message import Message
         headers = Message()
         headers['If-Modified-Since'] = last_modif
         response = self.request(self.base_url + '/test', headers=headers)
         self.check_status_and_reason(response, HTTPStatus.NOT_MODIFIED)
 
+        # if If-None-Match header is present, ignore If-Modified-Since
+        headers['If-None-Match'] = "*"
+        response = self.request(self.base_url + '/test', headers=headers)
+        self.check_status_and_reason(response, HTTPStatus.OK)        
+
+        # with If-Modified-Since earlier than Last-Modified, must return 200
+        import datetime
+        import email.utils
+        dt = email.utils.parsedate(last_modif)
+        # build datetime object : one year before last modification
+        old_dt = [dt[0] - 1] + list(dt[1:7])
+        old_dt = datetime.datetime(*old_dt)
+        headers = Message()
+        headers['If-Modified-Since'] = email.utils.format_datetime(old_dt)
+        response = self.request(self.base_url + '/test', headers=headers)
+        self.check_status_and_reason(response, HTTPStatus.OK)
+
+        # build datetime object : one hours after last modification
+        new_dt = [dt[0]] + [dt[1] + 1] + list(dt[2:7])
+        new_dt = datetime.datetime(*new_dt)
+        headers = Message()
+        headers['If-Modified-Since'] = email.utils.format_datetime(new_dt)
+        response = self.request(self.base_url + '/test', headers=headers)
+        self.check_status_and_reason(response, HTTPStatus.NOT_MODIFIED)
+        
+
     def test_invalid_requests(self):
         response = self.request('/', method='FOO')
         self.check_status_and_reason(response, HTTPStatus.NOT_IMPLEMENTED)

From c4403eca213a40d99c046b17900bacf279cb3eaa Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 10:22:43 +0100
Subject: [PATCH 03/22] Update Misc/NEWS and What's New

---
 Doc/whatsnew/3.7.rst | 6 ++++++
 Misc/NEWS            | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
index 35eea84e0a6c19..55f3042de026f9 100644
--- a/Doc/whatsnew/3.7.rst
+++ b/Doc/whatsnew/3.7.rst
@@ -110,6 +110,12 @@ urllib.parse
 adding `~` to the set of characters that is never quoted by default.
 (Contributed by Christian Theune and Ratnadeep Debnath in :issue:`16285`.)
 
+http.server
+-----------
+:class:`SimpleHTTPRequestHandler` supports the HTTP If-Modified-Since header.
+The server returns the 304 response status if the target file was not
+modified after the datetime specified in the header.
+(Contributed by Pierre Quentel in :issue:`29654`.)
 
 Optimizations
 =============
diff --git a/Misc/NEWS b/Misc/NEWS
index 74ec8c3bdf26e3..d9088d724c1872 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -666,6 +666,9 @@ Library
 - Issue #24142: Reading a corrupt config file left configparser in an
   invalid state.  Original patch by Florian Höch.
 
+- bpo-29654 : Support If-Modified-Since HTTP header (browser cache). Patch
+  by Pierre Quentel.
+
 Windows
 -------
 

From 3225080814bda8dd7670bed78fa766bcfeb6e1b5 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 10:53:35 +0100
Subject: [PATCH 04/22] Fix typo

---
 Lib/test/test_httpservers.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index 0ed2f7578936ab..732d2a1b1c882e 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -475,7 +475,7 @@ def test_browser_cache(self):
         response = self.request(self.base_url + '/test', headers=headers)
         self.check_status_and_reason(response, HTTPStatus.OK)
 
-        # build datetime object : one hours after last modification
+        # build datetime object : one hour after last modification
         new_dt = [dt[0]] + [dt[1] + 1] + list(dt[2:7])
         new_dt = datetime.datetime(*new_dt)
         headers = Message()

From 415e4af46a0fbea4593507b73b4b4be1a57e4f17 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 11:47:06 +0100
Subject: [PATCH 05/22] Use parsedate_to_datetime to extract datetime from
 If-Modified-Since, check that it's a valid HTTP date with timezone set to
 UTC.

---
 Lib/http/server.py | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index ca1c5fdcab2507..c54273c27d663c 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -692,19 +692,19 @@ def send_head(self):
             
         try:
             # Use browser cache if possible
-            if "If-Modified-Since" in self.headers \
-                    and not "If-None-Match" in self.headers:
-                # compare If-Modified-Since and date of last file modification
-                ims = email.utils.parsedate(self.headers["If-Modified-Since"])
-                if ims is not None:
-                    # If-Modified-Since is UTC, rounded to the second
-                    tzinfo = datetime.timezone(datetime.timedelta(hours=0))
-                    ims_datetime = datetime.datetime(*ims[:7], tzinfo=tzinfo)
-                    # compare to UTC datetime of last modification, also 
+            if ("If-Modified-Since" in self.headers
+                    and "If-None-Match" not in self.headers):
+                # compare If-Modified-Since and time of last file modification
+                ims = email.utils.parsedate_to_datetime(
+                    self.headers["If-Modified-Since"])
+                if (ims is not None and
+                        ims.tzinfo is datetime.timezone.utc):
+                    # compare to UTC datetime of last modification, 
                     # rounded to the second
                     mtime = int(fs.st_mtime)
-                    last_modif = datetime.datetime.fromtimestamp(mtime, tzinfo)
-                    if last_modif <= ims_datetime:
+                    last_modif = datetime.datetime.fromtimestamp(mtime, 
+                        ims.tzinfo)
+                    if last_modif <= ims:
                         self.send_response(HTTPStatus.NOT_MODIFIED)
                         self.end_headers()
                         f.close()

From 8595735d8fdab76cc017c169344ecd4a0fb7f3d7 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 11:48:14 +0100
Subject: [PATCH 06/22] Change computing of dates used to test browser cache

---
 Lib/test/test_httpservers.py | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index 732d2a1b1c882e..791760df1f3752 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -449,7 +449,7 @@ def test_browser_cache(self):
         response = self.request(self.base_url + '/test')
         self.check_status_and_reason(response, HTTPStatus.OK, data=self.data)
         last_modif = response.headers['Last-modified']
-
+        
         # send new request to the same url with request header 
         # If-Modified-Since set to Last-Modified : must return 304
         from email.message import Message
@@ -466,23 +466,22 @@ def test_browser_cache(self):
         # with If-Modified-Since earlier than Last-Modified, must return 200
         import datetime
         import email.utils
-        dt = email.utils.parsedate(last_modif)
-        # build datetime object : one year before last modification
-        old_dt = [dt[0] - 1] + list(dt[1:7])
-        old_dt = datetime.datetime(*old_dt)
+        dt = email.utils.parsedate_to_datetime(last_modif)
+        # build datetime object : 365 days before last modification
+        old_dt = dt - datetime.timedelta(days=365)
         headers = Message()
-        headers['If-Modified-Since'] = email.utils.format_datetime(old_dt)
+        headers['If-Modified-Since'] = email.utils.format_datetime(old_dt,
+            usegmt=True)
         response = self.request(self.base_url + '/test', headers=headers)
         self.check_status_and_reason(response, HTTPStatus.OK)
 
-        # build datetime object : one hour after last modification
-        new_dt = [dt[0]] + [dt[1] + 1] + list(dt[2:7])
-        new_dt = datetime.datetime(*new_dt)
+        # one hour after last modification : must return 304
+        new_dt = dt + datetime.timedelta(hours=1)
         headers = Message()
-        headers['If-Modified-Since'] = email.utils.format_datetime(new_dt)
+        headers['If-Modified-Since'] = email.utils.format_datetime(new_dt,
+            usegmt=True)
         response = self.request(self.base_url + '/test', headers=headers)
-        self.check_status_and_reason(response, HTTPStatus.NOT_MODIFIED)
-        
+        self.check_status_and_reason(response, HTTPStatus.NOT_MODIFIED)        
 
     def test_invalid_requests(self):
         response = self.request('/', method='FOO')

From 2be2f8c523fd5a4ed2d4154ebb8336943a71f5f8 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 12:01:15 +0100
Subject: [PATCH 07/22] Remove microseconds from time of last modification with
 .replace(microsecond=0) instead of int()

---
 Lib/http/server.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index c54273c27d663c..622d582879623c 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -699,11 +699,11 @@ def send_head(self):
                     self.headers["If-Modified-Since"])
                 if (ims is not None and
                         ims.tzinfo is datetime.timezone.utc):
-                    # compare to UTC datetime of last modification, 
-                    # rounded to the second
-                    mtime = int(fs.st_mtime)
-                    last_modif = datetime.datetime.fromtimestamp(mtime, 
+                    # compare to UTC datetime of last modification
+                    last_modif = datetime.datetime.fromtimestamp(fs.st_mtime, 
                         ims.tzinfo)
+                    # remove microseconds, like in If-Modified-Since
+                    last_modif = last_modif.replace(microsecond=0)
                     if last_modif <= ims:
                         self.send_response(HTTPStatus.NOT_MODIFIED)
                         self.end_headers()

From c3337f40207a402944b61e89b617b21599b0519e Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 15:20:23 +0100
Subject: [PATCH 08/22] Put os.fstat() call inside the try block ; handle
 obsolete HTTP date format ; ignore ill-formed values in If-Modified-Since
 header.

---
 Lib/http/server.py | 44 +++++++++++++++++++++++++++-----------------
 1 file changed, 27 insertions(+), 17 deletions(-)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index 622d582879623c..656084bec1a955 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -688,31 +688,41 @@ def send_head(self):
             self.send_error(HTTPStatus.NOT_FOUND, "File not found")
             return None
 
-        fs = os.fstat(f.fileno())
-            
         try:
+            fs = os.fstat(f.fileno())
             # Use browser cache if possible
             if ("If-Modified-Since" in self.headers
                     and "If-None-Match" not in self.headers):
                 # compare If-Modified-Since and time of last file modification
-                ims = email.utils.parsedate_to_datetime(
-                    self.headers["If-Modified-Since"])
-                if (ims is not None and
-                        ims.tzinfo is datetime.timezone.utc):
-                    # compare to UTC datetime of last modification
-                    last_modif = datetime.datetime.fromtimestamp(fs.st_mtime, 
-                        ims.tzinfo)
-                    # remove microseconds, like in If-Modified-Since
-                    last_modif = last_modif.replace(microsecond=0)
-                    if last_modif <= ims:
-                        self.send_response(HTTPStatus.NOT_MODIFIED)
-                        self.end_headers()
-                        f.close()
-                        return
+                try:
+                    ims = email.utils.parsedate_to_datetime(
+                        self.headers["If-Modified-Since"])
+                except:
+                    # ignore ill-formed values
+                    ims = None
+                if ims is not None:
+                    if ims.tzinfo is None:
+                        # obsolete format with no timezone, cf.
+                        # https://tools.ietf.org/html/rfc7231#section-7.1.1.1
+                        ims = ims.replace(tzinfo=datetime.timezone.utc)
+                    if ims.tzinfo is datetime.timezone.utc:
+                        # compare to UTC datetime of last modification
+                        last_modif = datetime.datetime.fromtimestamp(
+                            fs.st_mtime, datetime.timezone.utc)
+                        # remove microseconds, like in If-Modified-Since
+                        last_modif = last_modif.replace(microsecond=0)
+                        
+                        if last_modif <= ims:
+                            self.send_response(HTTPStatus.NOT_MODIFIED)
+                            self.end_headers()
+                            f.close()
+                            return None
+
             self.send_response(HTTPStatus.OK)
             self.send_header("Content-type", ctype)
             self.send_header("Content-Length", str(fs[6]))
-            self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
+            self.send_header("Last-Modified", 
+                self.date_time_string(fs.st_mtime))
             self.end_headers()
             return f
         except:

From 143e1e92324a60c800dceb6c6310e540e42c1e84 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 15:23:24 +0100
Subject: [PATCH 09/22] Restore alphabetical order in section Improved Modules

---
 Doc/whatsnew/3.7.rst | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
index 55f3042de026f9..4b7736137eca09 100644
--- a/Doc/whatsnew/3.7.rst
+++ b/Doc/whatsnew/3.7.rst
@@ -96,6 +96,13 @@ New Modules
 Improved Modules
 ================
 
+http.server
+-----------
+:class:`SimpleHTTPRequestHandler` supports the HTTP If-Modified-Since header.
+The server returns the 304 response status if the target file was not
+modified after the datetime specified in the header.
+(Contributed by Pierre Quentel in :issue:`29654`.)
+
 unittest.mock
 -------------
 
@@ -110,13 +117,6 @@ urllib.parse
 adding `~` to the set of characters that is never quoted by default.
 (Contributed by Christian Theune and Ratnadeep Debnath in :issue:`16285`.)
 
-http.server
------------
-:class:`SimpleHTTPRequestHandler` supports the HTTP If-Modified-Since header.
-The server returns the 304 response status if the target file was not
-modified after the datetime specified in the header.
-(Contributed by Pierre Quentel in :issue:`29654`.)
-
 Optimizations
 =============
 

From 42edfe3856e0ae683dbffe3f7a75b9daec0898e8 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sun, 26 Feb 2017 16:46:56 +0100
Subject: [PATCH 10/22] Store last modification date in setUp ; split browser
 cache tests in several methods ; add a test for Last-Modified header.

---
 Lib/test/test_httpservers.py | 64 +++++++++++++++++++++++-------------
 1 file changed, 41 insertions(+), 23 deletions(-)

diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index 791760df1f3752..182454e3c4ebec 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -17,8 +17,11 @@
 import urllib.parse
 import html
 import http.client
+import email.message
+import email.utils
 import tempfile
 import time
+import datetime
 from io import BytesIO
 
 import unittest
@@ -333,6 +336,13 @@ def setUp(self):
         self.base_url = '/' + self.tempdir_name
         with open(os.path.join(self.tempdir, 'test'), 'wb') as temp:
             temp.write(self.data)
+            mtime = os.fstat(temp.fileno()).st_mtime
+        # compute last modification datetime for browser cache tests
+        last_modif = datetime.datetime.fromtimestamp(mtime,
+            datetime.timezone.utc)
+        self.last_modif_datetime = last_modif.replace(microsecond=0)
+        self.last_modif_header = email.utils.formatdate(
+            last_modif.timestamp(), usegmt=True)
 
     def tearDown(self):
         try:
@@ -445,43 +455,42 @@ def test_head(self):
                          'application/octet-stream')
 
     def test_browser_cache(self):
-        #constructs the path relative to the root directory of the HTTPServer
-        response = self.request(self.base_url + '/test')
-        self.check_status_and_reason(response, HTTPStatus.OK, data=self.data)
-        last_modif = response.headers['Last-modified']
-        
-        # send new request to the same url with request header 
-        # If-Modified-Since set to Last-Modified : must return 304
-        from email.message import Message
-        headers = Message()
-        headers['If-Modified-Since'] = last_modif
+        """Check that when a request to /test is sent with the request header
+        If-Modified-Since set to date of last modification, the server returns
+        status code 304, not 200
+        """
+        headers = email.message.Message()
+        headers['If-Modified-Since'] = self.last_modif_header
         response = self.request(self.base_url + '/test', headers=headers)
         self.check_status_and_reason(response, HTTPStatus.NOT_MODIFIED)
 
-        # if If-None-Match header is present, ignore If-Modified-Since
-        headers['If-None-Match'] = "*"
+        # one hour after last modification : must return 304
+        new_dt = self.last_modif_datetime + datetime.timedelta(hours=1)
+        headers = email.message.Message()
+        headers['If-Modified-Since'] = email.utils.format_datetime(new_dt,
+            usegmt=True)
         response = self.request(self.base_url + '/test', headers=headers)
-        self.check_status_and_reason(response, HTTPStatus.OK)        
+        self.check_status_and_reason(response, HTTPStatus.NOT_MODIFIED)        
 
+    def test_browser_cache_file_changed(self):
         # with If-Modified-Since earlier than Last-Modified, must return 200
-        import datetime
-        import email.utils
-        dt = email.utils.parsedate_to_datetime(last_modif)
+        dt = self.last_modif_datetime
         # build datetime object : 365 days before last modification
         old_dt = dt - datetime.timedelta(days=365)
-        headers = Message()
+        headers = email.message.Message()
         headers['If-Modified-Since'] = email.utils.format_datetime(old_dt,
             usegmt=True)
         response = self.request(self.base_url + '/test', headers=headers)
         self.check_status_and_reason(response, HTTPStatus.OK)
 
-        # one hour after last modification : must return 304
-        new_dt = dt + datetime.timedelta(hours=1)
-        headers = Message()
-        headers['If-Modified-Since'] = email.utils.format_datetime(new_dt,
-            usegmt=True)
+    def test_browser_cache_with_If_None_Match_header(self):
+        # if If-None-Match header is present, ignore If-Modified-Since
+
+        headers = email.message.Message()
+        headers['If-Modified-Since'] = self.last_modif_header
+        headers['If-None-Match'] = "*"
         response = self.request(self.base_url + '/test', headers=headers)
-        self.check_status_and_reason(response, HTTPStatus.NOT_MODIFIED)        
+        self.check_status_and_reason(response, HTTPStatus.OK)        
 
     def test_invalid_requests(self):
         response = self.request('/', method='FOO')
@@ -492,6 +501,15 @@ def test_invalid_requests(self):
         response = self.request('/', method='GETs')
         self.check_status_and_reason(response, HTTPStatus.NOT_IMPLEMENTED)
 
+    def test_last_modified(self):
+        """Checks that the datetime returned in Last-Modified response header
+        is the actual datetime of last modification, rounded to the second
+        """
+        response = self.request(self.base_url + '/test')
+        self.check_status_and_reason(response, HTTPStatus.OK, data=self.data)
+        last_modif_header = response.headers['Last-modified']
+        self.assertEqual(last_modif_header, self.last_modif_header)
+
     def test_path_without_leading_slash(self):
         response = self.request(self.tempdir_name + '/test')
         self.check_status_and_reason(response, HTTPStatus.OK, data=self.data)

From 1e68be9e1e68e5c483f01043ba0d081a2e538290 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@gmail.com>
Date: Mon, 27 Feb 2017 09:08:11 +0100
Subject: [PATCH 11/22] Specify the exceptions to catch in
 parsedate_to_datetime

---
 Lib/http/server.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index 656084bec1a955..702cdbb7d09c7f 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -697,7 +697,7 @@ def send_head(self):
                 try:
                     ims = email.utils.parsedate_to_datetime(
                         self.headers["If-Modified-Since"])
-                except:
+                except (TypeError, IndexError, OverflowError, ValueError):
                     # ignore ill-formed values
                     ims = None
                 if ims is not None:

From fc2059693a12601302d6eb5c084b2cf01dffc3c5 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@gmail.com>
Date: Mon, 27 Feb 2017 09:40:10 +0100
Subject: [PATCH 12/22] Use except/else for parsedate_to_datetime exception
 handling

---
 Lib/http/server.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index 702cdbb7d09c7f..a164eea08acf72 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -699,8 +699,8 @@ def send_head(self):
                         self.headers["If-Modified-Since"])
                 except (TypeError, IndexError, OverflowError, ValueError):
                     # ignore ill-formed values
-                    ims = None
-                if ims is not None:
+                    pass
+                else:
                     if ims.tzinfo is None:
                         # obsolete format with no timezone, cf.
                         # https://tools.ietf.org/html/rfc7231#section-7.1.1.1
@@ -1243,4 +1243,3 @@ def test(HandlerClass=BaseHTTPRequestHandler,
     else:
         handler_class = SimpleHTTPRequestHandler
     test(HandlerClass=handler_class, port=args.port, bind=args.bind)
-

From 9436e45fd7238c83be1546bf96f289c712cf4b6a Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Tue, 28 Feb 2017 08:47:38 +0100
Subject: [PATCH 13/22] Restore blank line

---
 Doc/whatsnew/3.7.rst | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
index 4b7736137eca09..f5b92b31374902 100644
--- a/Doc/whatsnew/3.7.rst
+++ b/Doc/whatsnew/3.7.rst
@@ -117,6 +117,7 @@ urllib.parse
 adding `~` to the set of characters that is never quoted by default.
 (Contributed by Christian Theune and Ratnadeep Debnath in :issue:`16285`.)
 
+
 Optimizations
 =============
 

From 708ff034a7055f34a1845bd5fce7bb2efed14164 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Wed, 1 Mar 2017 13:44:21 +0100
Subject: [PATCH 14/22] Put imports in alphabetical order. Change version to
 0.7.

---
 Lib/http/server.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index a164eea08acf72..36e1ecc6ab1791 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -80,13 +80,16 @@
 # (Actually, the latter is only true if you know the server configuration
 # at the time the request was made!)
 
-__version__ = "0.6"
+__version__ = "0.7"
 
 __all__ = [
     "HTTPServer", "BaseHTTPRequestHandler",
     "SimpleHTTPRequestHandler", "CGIHTTPRequestHandler",
 ]
 
+import argparse
+import copy
+import datetime
 import email.utils
 import html
 import http.client
@@ -100,10 +103,7 @@
 import socketserver
 import sys
 import time
-import datetime
 import urllib.parse
-import copy
-import argparse
 
 from http import HTTPStatus
 

From 6a58894e49915ef11339d4e31d4f544ff324f0ec Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Wed, 1 Mar 2017 16:32:37 +0100
Subject: [PATCH 15/22] Presentation changes.

---
 Doc/whatsnew/3.7.rst | 6 +++---
 Misc/NEWS            | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
index f5b92b31374902..288213723ed3dc 100644
--- a/Doc/whatsnew/3.7.rst
+++ b/Doc/whatsnew/3.7.rst
@@ -98,9 +98,9 @@ Improved Modules
 
 http.server
 -----------
-:class:`SimpleHTTPRequestHandler` supports the HTTP If-Modified-Since header.
-The server returns the 304 response status if the target file was not
-modified after the datetime specified in the header.
+:class:`~http.server.SimpleHTTPRequestHandler` supports the HTTP
+If-Modified-Since header. The server returns the 304 response status if the
+target file was not modified after the datetime specified in the header.
 (Contributed by Pierre Quentel in :issue:`29654`.)
 
 unittest.mock
diff --git a/Misc/NEWS b/Misc/NEWS
index d9088d724c1872..bd654f96383a63 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -249,6 +249,9 @@ Extension Modules
 Library
 -------
 
+- bpo-29654: Support If-Modified-Since HTTP header (browser cache).  Patch
+  by Pierre Quentel.
+
 - Issue #16285: urrlib.parse.quote is now based on RFC 3986 and hence includes
   '~' in the set of characters that is not quoted by default. Patch by
   Christian Theune and Ratnadeep Debnath.
@@ -666,9 +669,6 @@ Library
 - Issue #24142: Reading a corrupt config file left configparser in an
   invalid state.  Original patch by Florian Höch.
 
-- bpo-29654 : Support If-Modified-Since HTTP header (browser cache). Patch
-  by Pierre Quentel.
-
 Windows
 -------
 

From db46671509567a026c32c5a33b0ef6c709dcc903 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Wed, 1 Mar 2017 16:41:21 +0100
Subject: [PATCH 16/22] Change order of imports.

---
 Lib/test/test_httpservers.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index 182454e3c4ebec..dafcb0cbd56ba3 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -14,11 +14,11 @@
 import base64
 import ntpath
 import shutil
-import urllib.parse
-import html
-import http.client
 import email.message
 import email.utils
+import html
+import http.client
+import urllib.parse
 import tempfile
 import time
 import datetime

From 41f74efd9676b2df67a6af6b0626f184fb37d334 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Thu, 2 Mar 2017 09:10:12 +0100
Subject: [PATCH 17/22] Update Misc/NEWS (conflict)

---
 Misc/NEWS | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/Misc/NEWS b/Misc/NEWS
index bd654f96383a63..cf2ff39af6b533 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,10 +10,14 @@ What's New in Python 3.7.0 alpha 1?
 Core and Builtins
 -----------------
 
+- bpo-29684: Fix minor regression of PyEval_CallObjectWithKeywords.
+  It should raise TypeError when kwargs is not a dict.  But it might
+  cause segv when args=NULL and kwargs is not a dict.
+
 - bpo-28598: Support __rmod__ for subclasses of str being called before
   str.__mod__.  Patch by Martijn Pieters.
 
-- bpo-29607: Fix stack_effect computation for CALL_FUNCTION_EX. 
+- bpo-29607: Fix stack_effect computation for CALL_FUNCTION_EX.
   Patch by Matthieu Dartiailh.
 
 - bpo-29602: Fix incorrect handling of signed zeros in complex constructor for
@@ -251,6 +255,21 @@ Library
 
 - bpo-29654: Support If-Modified-Since HTTP header (browser cache).  Patch
   by Pierre Quentel.
+  
+- bpo-29615: SimpleXMLRPCDispatcher no longer chains KeyError (or any other
+  exception) to exception(s) raised in the dispatched methods.
+  Patch by Petr Motejlek.
+
+- bpo-7769: Method register_function() of xmlrpc.server.SimpleXMLRPCDispatcher
+  and its subclasses can now be used as a decorator.
+
+- bpo-29376: Fix assertion error in threading._DummyThread.is_alive().
+
+- bpo-28624: Add a test that checks that cwd parameter of Popen() accepts
+  PathLike objects.  Patch by Sayan Chowdhury.
+
+- bpo-28518: Start a transaction implicitly before a DML statement.
+  Patch by Aviv Palivoda.
 
 - Issue #16285: urrlib.parse.quote is now based on RFC 3986 and hence includes
   '~' in the set of characters that is not quoted by default. Patch by
@@ -1246,6 +1265,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #26128: Added keyword-only arguments support for
+  subprocess.STARTUPINFO
+
 - Issue #27517: LZMA compressor and decompressor no longer raise exceptions if
   given empty data twice.  Patch by Benjamin Fogle.
 

From 6dadf6ec3fd18cf12d56155fcf4275557cc62391 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Tue, 7 Mar 2017 08:30:08 +0100
Subject: [PATCH 18/22] Restore version number 0.6

---
 Lib/http/server.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/http/server.py b/Lib/http/server.py
index 36e1ecc6ab1791..429490b73a88b7 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -80,7 +80,7 @@
 # (Actually, the latter is only true if you know the server configuration
 # at the time the request was made!)
 
-__version__ = "0.7"
+__version__ = "0.6"
 
 __all__ = [
     "HTTPServer", "BaseHTTPRequestHandler",

From c389bf69fd79ee1208d3f18918e901ff3b4c3550 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Tue, 7 Mar 2017 08:30:32 +0100
Subject: [PATCH 19/22] Replace "datetime" by "time"

---
 Doc/whatsnew/3.7.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
index 288213723ed3dc..ed1c4fb44b1724 100644
--- a/Doc/whatsnew/3.7.rst
+++ b/Doc/whatsnew/3.7.rst
@@ -100,7 +100,7 @@ http.server
 -----------
 :class:`~http.server.SimpleHTTPRequestHandler` supports the HTTP
 If-Modified-Since header. The server returns the 304 response status if the
-target file was not modified after the datetime specified in the header.
+target file was not modified after the time specified in the header.
 (Contributed by Pierre Quentel in :issue:`29654`.)
 
 unittest.mock

From 294e1648c4f06694715b9d9081018460afbc4854 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Tue, 7 Mar 2017 08:43:20 +0100
Subject: [PATCH 20/22] Proposal for an update of the http.server module
 documentation

---
 Doc/library/http.server.rst | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Doc/library/http.server.rst b/Doc/library/http.server.rst
index fb5c1df611d8f2..2487cbff0578ae 100644
--- a/Doc/library/http.server.rst
+++ b/Doc/library/http.server.rst
@@ -343,11 +343,13 @@ of which this module provides three different variants:
       :func:`os.listdir` to scan the directory, and returns a ``404`` error
       response if the :func:`~os.listdir` fails.
 
-      If the request was mapped to a file, it is opened and the contents are
-      returned.  Any :exc:`OSError` exception in opening the requested file is
-      mapped to a ``404``, ``'File not found'`` error. Otherwise, the content
+      If the request was mapped to a file, it is opened. Any :exc:`OSError` 
+      exception in opening the requested file is mapped to a ``404``, 
+      ``'File not found'`` error. If there was a ``'If-Modified-Since'`` 
+      header in the request, and the file was not modified after this time,
+      a ``304``, ``'Not Modified'`` response is sent. Otherwise, the content
       type is guessed by calling the :meth:`guess_type` method, which in turn
-      uses the *extensions_map* variable.
+      uses the *extensions_map* variable, and the file contents are returned.
 
       A ``'Content-type:'`` header with the guessed content type is output,
       followed by a ``'Content-Length:'`` header with the file's size and a

From c8b108fc3c2ab66cb218c0f4e5da39d40c5fa035 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Fri, 24 Mar 2017 08:56:46 +0100
Subject: [PATCH 21/22] Add a "Changed in version 3.7" comment

---
 Doc/library/http.server.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Doc/library/http.server.rst b/Doc/library/http.server.rst
index 2487cbff0578ae..303ef778ad349b 100644
--- a/Doc/library/http.server.rst
+++ b/Doc/library/http.server.rst
@@ -362,6 +362,8 @@ of which this module provides three different variants:
       For example usage, see the implementation of the :func:`test` function
       invocation in the :mod:`http.server` module.
 
+      .. versionchanged:: 3.7
+         Support of the ``'If-Modified-Since'`` header.
 
 The :class:`SimpleHTTPRequestHandler` class can be used in the following
 manner in order to create a very basic webserver serving files relative to

From 16f9e1139202bfedb9314bdac8e5d8fef0d2f4f2 Mon Sep 17 00:00:00 2001
From: Pierre Quentel <pierre.quentel@orange.com>
Date: Sat, 1 Apr 2017 22:28:51 +0200
Subject: [PATCH 22/22] Remove trailing whitespaces

---
 Doc/library/http.server.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Doc/library/http.server.rst b/Doc/library/http.server.rst
index 303ef778ad349b..ee1c37c631941b 100644
--- a/Doc/library/http.server.rst
+++ b/Doc/library/http.server.rst
@@ -343,9 +343,9 @@ of which this module provides three different variants:
       :func:`os.listdir` to scan the directory, and returns a ``404`` error
       response if the :func:`~os.listdir` fails.
 
-      If the request was mapped to a file, it is opened. Any :exc:`OSError` 
-      exception in opening the requested file is mapped to a ``404``, 
-      ``'File not found'`` error. If there was a ``'If-Modified-Since'`` 
+      If the request was mapped to a file, it is opened. Any :exc:`OSError`
+      exception in opening the requested file is mapped to a ``404``,
+      ``'File not found'`` error. If there was a ``'If-Modified-Since'``
       header in the request, and the file was not modified after this time,
       a ``304``, ``'Not Modified'`` response is sent. Otherwise, the content
       type is guessed by calling the :meth:`guess_type` method, which in turn