From e038a71053b2456c70c11fd3be471fcd9f048ad9 Mon Sep 17 00:00:00 2001
From: "brett.cannon" <brett.cannon@6015fed2-1504-0410-9fe1-9d1591cc4771>
Date: Thu, 14 Jan 2010 20:00:28 +0000
Subject: [PATCH] The silencing of DeprecationWarning was not taking -3 into
 consideration. Since Py3K warnings are DeprecationWarning by default this was
 causing -3 to essentially be a no-op. Now DeprecationWarning is only silenced
 if -3 is not used.

Closes issue #7700. Thanks Ezio Melotti and Florent Xicluna for patch help.


git-svn-id: http://svn.python.org/projects/python/trunk@77505 6015fed2-1504-0410-9fe1-9d1591cc4771
---
 Lib/warnings.py    |  7 +++++--
 Misc/NEWS          |  3 ++-
 Python/_warnings.c | 30 ++++++++++++++++++------------
 3 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/Lib/warnings.py b/Lib/warnings.py
index a88e7ba52b..70b3d43619 100644
--- a/Lib/warnings.py
+++ b/Lib/warnings.py
@@ -383,8 +383,11 @@ except ImportError:
 # Module initialization
 _processoptions(sys.warnoptions)
 if not _warnings_defaults:
-    for cls in (DeprecationWarning, PendingDeprecationWarning, ImportWarning):
-        simplefilter("ignore", category=cls, append=True)
+    silence = [ImportWarning, PendingDeprecationWarning]
+    if not sys.py3kwarning:  # Don't silence DeprecationWarning if -3 was used.
+        silence.append(DeprecationWarning)
+    for cls in silence:
+        simplefilter("ignore", category=cls)
     bytes_warning = sys.flags.bytes_warning
     if bytes_warning > 1:
         bytes_action = "error"
diff --git a/Misc/NEWS b/Misc/NEWS
index 2f90b5e158..16f1cdb4f5 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -21,7 +21,8 @@ Core and Builtins
   values.  Also fix a number of bugs in dtoa.c that could lead to
   incorrectly rounded results when converting strings to floats.
 
-- Issue #7319: Silence DeprecationWarning by default.
+- Issue #7319, #7770: Silence DeprecationWarning by default when -3 is not
+  used.
 
 - Issue #2335: Backport set literals syntax from Python 3.x.
 
diff --git a/Python/_warnings.c b/Python/_warnings.c
index 96bb0493c9..f3b2286e69 100644
--- a/Python/_warnings.c
+++ b/Python/_warnings.c
@@ -839,31 +839,37 @@ create_filter(PyObject *category, const char *action)
 static PyObject *
 init_filters(void)
 {
-    PyObject *filters = PyList_New(4);
+    // Don't silence DeprecationWarning if -3 was used.
+    PyObject *filters = PyList_New(Py_Py3kWarningFlag ? 3 : 4);
+    unsigned int pos = 0;  // Post-incremented in each use.
+    unsigned int x;
     const char *bytes_action;
+
     if (filters == NULL)
         return NULL;
 
-    PyList_SET_ITEM(filters, 0,
-                    create_filter(PyExc_DeprecationWarning, "ignore"));
-    PyList_SET_ITEM(filters, 1,
+    if (!Py_Py3kWarningFlag) {
+        PyList_SET_ITEM(filters, pos++,
+                        create_filter(PyExc_DeprecationWarning, "ignore"));
+    }
+    PyList_SET_ITEM(filters, pos++,
                     create_filter(PyExc_PendingDeprecationWarning, "ignore"));
-    PyList_SET_ITEM(filters, 2, create_filter(PyExc_ImportWarning, "ignore"));
+    PyList_SET_ITEM(filters, pos++,
+                    create_filter(PyExc_ImportWarning, "ignore"));
     if (Py_BytesWarningFlag > 1)
         bytes_action = "error";
     else if (Py_BytesWarningFlag)
         bytes_action = "default";
     else
         bytes_action = "ignore";
-    PyList_SET_ITEM(filters, 3, create_filter(PyExc_BytesWarning,
+    PyList_SET_ITEM(filters, pos++, create_filter(PyExc_BytesWarning,
                     bytes_action));
 
-    if (PyList_GET_ITEM(filters, 0) == NULL ||
-        PyList_GET_ITEM(filters, 1) == NULL ||
-        PyList_GET_ITEM(filters, 2) == NULL ||
-        PyList_GET_ITEM(filters, 3) == NULL) {
-        Py_DECREF(filters);
-        return NULL;
+    for (x = 0; x < pos; x += 1) {
+        if (PyList_GET_ITEM(filters, x) == NULL) {
+            Py_DECREF(filters);
+            return NULL;
+        }
     }
 
     return filters;
-- 
2.11.4.GIT