#3996: On Windows, PyOS_CheckStack is supposed to protect the interpreter from

stack overflow. But doing this, it always crashes when the stack is nearly full.

Reviewed by Martin von Loewis. Will backport to 2.6.

diff --git a/Misc/NEWS b/Misc/NEWS
index c3f0ec61e1b77268ce5fc6770bfc2b0527d9672b..b7e80a9d2dfc2dbfd58eefde706dde6800551e4e 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,10 @@ What's New in Python 2.7 alpha 1
 Core and Builtins
 -----------------
 
+- Issue #3996: On Windows, the PyOS_CheckStack function would cause the
+  interpreter to abort ("Fatal Python error: Could not reset the stack!")
+  instead of throwing a MemoryError.
+
 - Issue #4367: Python would segfault during compiling when the unicodedata
   module couldn't be imported and \N escapes were present.
 

diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 4ff70d8543022f0292dd7fb4607160a8e5da5bf7..54f3c5784bd86b1384e07ad4214890a971111a2d 100644 (file)
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -1755,7 +1755,7 @@ PyOS_CheckStack(void)
                        EXCEPTION_EXECUTE_HANDLER : 
                        EXCEPTION_CONTINUE_SEARCH) {
                int errcode = _resetstkoflw();
-               if (errcode)
+               if (errcode == 0)
                {
                        Py_FatalError("Could not reset the stack!");
                }