[Python-checkins] cpython (merge 3.3 -> default): #17572: merge with 3.3.

[ezio.melotti]

http://hg.python.org/cpython/rev/d408c9bd4bf7
changeset:   83092:d408c9bd4bf7
parent:      83089:a8a238cf59c7
parent:      83091:3203e083aa7b
user:        Ezio Melotti <ezio.melotti at gmail.com>
date:        Thu Apr 04 02:16:27 2013 +0300
summary:
  #17572: merge with 3.3.

files:
  Lib/_strptime.py          |  2 +-
  Lib/test/test_strptime.py |  6 ++++++
  Lib/test/test_time.py     |  6 ++++++
  Misc/NEWS                 |  3 +++
  4 files changed, 16 insertions(+), 1 deletions(-)


diff --git a/Lib/_strptime.py b/Lib/_strptime.py
--- a/Lib/_strptime.py
+++ b/Lib/_strptime.py
@@ -326,7 +326,7 @@
                     bad_directive = "%"
                 del err
                 raise ValueError("'%s' is a bad directive in format '%s'" %
-                                    (bad_directive, format))
+                                    (bad_directive, format)) from None
             # IndexError only occurs when the format string is "%"
             except IndexError:
                 raise ValueError("stray %% in format '%s'" % format)
diff --git a/Lib/test/test_strptime.py b/Lib/test/test_strptime.py
--- a/Lib/test/test_strptime.py
+++ b/Lib/test/test_strptime.py
@@ -218,6 +218,12 @@
             else:
                 self.fail("'%s' did not raise ValueError" % bad_format)
 
+    def test_strptime_exception_context(self):
+        # check that this doesn't chain exceptions needlessly (see #17572)
+        with self.assertRaises(ValueError) as e:
+            _strptime._strptime_time('', '%D')
+        self.assertIs(e.exception.__suppress_context__, True)
+
     def test_unconverteddata(self):
         # Check ValueError is raised when there is unconverted data
         self.assertRaises(ValueError, _strptime._strptime_time, "10 12", "%m")
diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py
--- a/Lib/test/test_time.py
+++ b/Lib/test/test_time.py
@@ -193,6 +193,12 @@
         self.assertRaises(TypeError, time.strptime, b'2009', "%Y")
         self.assertRaises(TypeError, time.strptime, '2009', b'%Y')
 
+    def test_strptime_exception_context(self):
+        # check that this doesn't chain exceptions needlessly (see #17572)
+        with self.assertRaises(ValueError) as e:
+            time.strptime('', '%D')
+        self.assertIs(e.exception.__suppress_context__, True)
+
     def test_asctime(self):
         time.asctime(time.gmtime(self.t))
 
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -304,6 +304,9 @@
 Library
 -------
 
+- Issue #17572: Avoid chained exceptions while passing bad directives to
+  time.strptime().  Initial patch by Claudiu Popa.
+
 - Issue #14254: IDLE now handles readline correctly across shell restarts.
 
 - Issue #17614: IDLE no longer raises exception when quickly closing a file.

-- 
Repository URL: http://hg.python.org/cpython