From: Victor Stinner <vstinner@redhat.com>
Date: Mon, 19 Aug 2019 22:40:39 +0000 (+0200)
Subject: Fix TracebackFrameProxy.set_next() on Python 3.7
X-Git-Tag: 2.10.2~2^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3a86ef3d72fdefb149c0c859e6e37035826f3557;p=thirdparty%2Fjinja.git

Fix TracebackFrameProxy.set_next() on Python 3.7

Fix issue #1050: fix a crash in TracebackFrameProxy.set_next() on
Python 3.7 and newer, when Python is build in debug mode.

Since Python 3.7, traceback.tb_next field can be modified: ctypes is
no longer needed.
---

diff --git a/CHANGES.rst b/CHANGES.rst
index 3199d559..9bf04814 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -8,6 +8,8 @@ Unreleased
 -   Fix Python 3.7 deprecation warnings.
 -   Using ``range`` in the sandboxed environment uses ``xrange`` on
     Python 2 to avoid memory use. :issue:`933`
+-   Use Python 3.7's better traceback support to avoid a core dump when
+    using debug builds of Python 3.7. :issue:`1050`
 
 
 Version 2.10.1
diff --git a/jinja2/debug.py b/jinja2/debug.py
index b61139f0..d3c1a3a8 100644
--- a/jinja2/debug.py
+++ b/jinja2/debug.py
@@ -365,8 +365,14 @@ def _init_ugly_crap():
 # proxies.
 tb_set_next = None
 if tproxy is None:
-    try:
-        tb_set_next = _init_ugly_crap()
-    except:
-        pass
-    del _init_ugly_crap
+    # traceback.tb_next can be modified since CPython 3.7
+    if sys.version_info >= (3, 7):
+        def tb_set_next(tb, next):
+            tb.tb_next = next
+    else:
+        # On Python 3.6 and older, use ctypes
+        try:
+            tb_set_next = _init_ugly_crap()
+        except Exception:
+            pass
+del _init_ugly_crap