From 5de9842b34cbefbfe74e6a99004616352f223133 Mon Sep 17 00:00:00 2001 From: Tim Peters Date: Sat, 27 Apr 2002 18:44:32 +0000 Subject: Repair widespread misuse of _PyString_Resize. Since it's clear people don't understand how this function works, also beefed up the docs. The most common usage error is of this form (often spread out across gotos): if (_PyString_Resize(&s, n) < 0) { Py_DECREF(s); s = NULL; goto outtahere; } The error is that if _PyString_Resize runs out of memory, it automatically decrefs the input string object s (which also deallocates it, since its refcount must be 1 upon entry), and sets s to NULL. So if the "if" branch ever triggers, it's an error to call Py_DECREF(s): s is already NULL! A correct way to write the above is the simpler (and intended) if (_PyString_Resize(&s, n) < 0) goto outtahere; Bugfix candidate. --- Modules/regexmodule.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'Modules/regexmodule.c') diff --git a/Modules/regexmodule.c b/Modules/regexmodule.c index d449604cb8..4c7035e501 100644 --- a/Modules/regexmodule.c +++ b/Modules/regexmodule.c @@ -516,11 +516,8 @@ symcomp(PyObject *pattern, PyObject *gdict) return NULL; } /* _PyString_Resize() decrements npattern on failure */ - if (_PyString_Resize(&npattern, n - v) == 0) - return npattern; - else { - return NULL; - } + _PyString_Resize(&npattern, n - v); + return npattern; } -- cgit v1.2.1