Mailing List Archive

Update of /cvsroot/python/python/dist/src/Modules
In directory usw-pr-cvs1:/tmp/cvs-serv7685/python/Modules

Modified Files:
_ssl.c cPickle.c cdmodule.c clmodule.c linuxaudiodev.c
regexmodule.c socketmodule.c stropmodule.c zlibmodule.c
Log Message:
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.


Index: _ssl.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/_ssl.c,v
retrieving revision 1.2
retrieving revision 1.3
diff -C2 -d -r1.2 -r1.3
*** _ssl.c 20 Apr 2002 07:47:40 -0000 1.2
--- _ssl.c 27 Apr 2002 18:44:29 -0000 1.3
***************
*** 332,337 ****
return PySSL_SetError(self, count);
}
! if (count != len && _PyString_Resize(&buf, count) < 0)
! return NULL;
return buf;
}
--- 332,337 ----
return PySSL_SetError(self, count);
}
! if (count != len)
! _PyString_Resize(&buf, count);
return buf;
}

Index: cPickle.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/cPickle.c,v
retrieving revision 2.82
retrieving revision 2.83
diff -C2 -d -r2.82 -r2.83
*** cPickle.c 21 Apr 2002 23:44:34 -0000 2.82
--- cPickle.c 27 Apr 2002 18:44:29 -0000 2.83
***************
*** 1253,1264 ****
}
*p = '\0';
! if (_PyString_Resize(&repr, p - q))
! goto onError;
!
return repr;
-
- onError:
- Py_DECREF(repr);
- return NULL;
}

--- 1253,1258 ----
}
*p = '\0';
! _PyString_Resize(&repr, p - q);
return repr;
}


Index: cdmodule.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/cdmodule.c,v
retrieving revision 1.27
retrieving revision 1.28
diff -C2 -d -r1.27 -r1.28
*** cdmodule.c 17 Jan 2002 23:15:58 -0000 1.27
--- cdmodule.c 27 Apr 2002 18:44:31 -0000 1.28
***************
*** 252,257 ****
}
if (n < numframes)
! if (_PyString_Resize(&result, n * sizeof(CDFRAME)))
! return NULL;

return result;
--- 252,256 ----
}
if (n < numframes)
! _PyString_Resize(&result, n * sizeof(CDFRAME));

return result;

Index: clmodule.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/clmodule.c,v
retrieving revision 2.28
retrieving revision 2.29
diff -C2 -d -r2.28 -r2.29
*** clmodule.c 2 Apr 2002 18:26:33 -0000 2.28
--- clmodule.c 27 Apr 2002 18:44:31 -0000 2.29
***************
*** 136,141 ****

if (compressedBufferSize < frameBufferSize)
! if (_PyString_Resize(&compressedBuffer, compressedBufferSize))
! return NULL;

return compressedBuffer;
--- 136,140 ----

if (compressedBufferSize < frameBufferSize)
! _PyString_Resize(&compressedBuffer, compressedBufferSize);

return compressedBuffer;

Index: linuxaudiodev.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/linuxaudiodev.c,v
retrieving revision 2.17
retrieving revision 2.18
diff -C2 -d -r2.17 -r2.18
*** linuxaudiodev.c 12 Jan 2002 11:05:06 -0000 2.17
--- linuxaudiodev.c 27 Apr 2002 18:44:31 -0000 2.18
***************
*** 159,164 ****
}
self->x_icount += count;
! if (_PyString_Resize(&rv, count) == -1)
! return NULL;
return rv;
}
--- 159,163 ----
}
self->x_icount += count;
! _PyString_Resize(&rv, count);
return rv;
}

Index: regexmodule.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/regexmodule.c,v
retrieving revision 1.47
retrieving revision 1.48
diff -C2 -d -r1.47 -r1.48
*** regexmodule.c 31 Mar 2002 15:27:00 -0000 1.47
--- regexmodule.c 27 Apr 2002 18:44:31 -0000 1.48
***************
*** 517,525 ****
}
/* _PyString_Resize() decrements npattern on failure */
! if (_PyString_Resize(&npattern, n - v) == 0)
! return npattern;
! else {
! return NULL;
! }

}
--- 517,522 ----
}
/* _PyString_Resize() decrements npattern on failure */
! _PyString_Resize(&npattern, n - v);
! return npattern;

}

Index: socketmodule.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/socketmodule.c,v
retrieving revision 1.215
retrieving revision 1.216
diff -C2 -d -r1.215 -r1.216
*** socketmodule.c 12 Apr 2002 02:41:24 -0000 1.215
--- socketmodule.c 27 Apr 2002 18:44:31 -0000 1.216
***************
*** 1403,1408 ****
return s->errorhandler();
}
! if (n != len && _PyString_Resize(&buf, n) < 0)
! return NULL;
return buf;
}
--- 1403,1408 ----
return s->errorhandler();
}
! if (n != len)
! _PyString_Resize(&buf, n);
return buf;
}

Index: stropmodule.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/stropmodule.c,v
retrieving revision 2.87
retrieving revision 2.88
diff -C2 -d -r2.87 -r2.88
*** stropmodule.c 2 Apr 2002 18:17:57 -0000 2.87
--- stropmodule.c 27 Apr 2002 18:44:31 -0000 2.88
***************
*** 216,223 ****
slen = PyString_GET_SIZE(item);
while (reslen + slen + seplen >= sz) {
! if (_PyString_Resize(&res, sz * 2)) {
! Py_DECREF(res);
return NULL;
- }
sz *= 2;
p = PyString_AsString(res) + reslen;
--- 216,221 ----
slen = PyString_GET_SIZE(item);
while (reslen + slen + seplen >= sz) {
! if (_PyString_Resize(&res, sz * 2) < 0)
return NULL;
sz *= 2;
p = PyString_AsString(res) + reslen;
***************
*** 232,239 ****
reslen += slen;
}
! if (_PyString_Resize(&res, reslen)) {
! Py_DECREF(res);
! res = NULL;
! }
return res;
}
--- 230,234 ----
reslen += slen;
}
! _PyString_Resize(&res, reslen);
return res;
}
***************
*** 258,263 ****
slen = PyString_GET_SIZE(item);
while (reslen + slen + seplen >= sz) {
! if (_PyString_Resize(&res, sz * 2)) {
! Py_DECREF(res);
Py_DECREF(item);
return NULL;
--- 253,257 ----
slen = PyString_GET_SIZE(item);
while (reslen + slen + seplen >= sz) {
! if (_PyString_Resize(&res, sz * 2) < 0) {
Py_DECREF(item);
return NULL;
***************
*** 276,283 ****
Py_DECREF(item);
}
! if (_PyString_Resize(&res, reslen)) {
! Py_DECREF(res);
! res = NULL;
! }
return res;
}
--- 270,274 ----
Py_DECREF(item);
}
! _PyString_Resize(&res, reslen);
return res;
}
***************
*** 990,995 ****
}
/* Fix the size of the resulting string */
! if (inlen > 0 &&_PyString_Resize(&result, output-output_start))
! return NULL;
return result;
}
--- 981,986 ----
}
/* Fix the size of the resulting string */
! if (inlen > 0)
! _PyString_Resize(&result, output - output_start);
return result;
}

Index: zlibmodule.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/zlibmodule.c,v
retrieving revision 2.60
retrieving revision 2.61
diff -C2 -d -r2.60 -r2.61
*** zlibmodule.c 19 Apr 2002 14:37:07 -0000 2.60
--- zlibmodule.c 27 Apr 2002 18:44:31 -0000 2.61
***************
*** 256,262 ****
case(Z_OK):
/* need more memory */
! if (_PyString_Resize(&result_str, r_strlen << 1) == -1) {
inflateEnd(&zst);
- result_str = NULL;
goto error;
}
--- 256,261 ----
case(Z_OK):
/* need more memory */
! if (_PyString_Resize(&result_str, r_strlen << 1) < 0) {
inflateEnd(&zst);
goto error;
}
***************
*** 415,422 ****
so extend the output buffer and try again */
while (err == Z_OK && self->zst.avail_out == 0) {
! if (_PyString_Resize(&RetVal, length << 1) == -1) {
! RetVal = NULL;
goto error;
- }
self->zst.next_out = (unsigned char *)PyString_AS_STRING(RetVal) \
+ length;
--- 414,419 ----
so extend the output buffer and try again */
while (err == Z_OK && self->zst.avail_out == 0) {
! if (_PyString_Resize(&RetVal, length << 1) < 0)
goto error;
self->zst.next_out = (unsigned char *)PyString_AS_STRING(RetVal) \
+ length;
***************
*** 439,445 ****
goto error;
}
! if (_PyString_Resize(&RetVal,
! self->zst.total_out - start_total_out) < 0)
! RetVal = NULL;

error:
--- 436,440 ----
goto error;
}
! _PyString_Resize(&RetVal, self->zst.total_out - start_total_out);

error:
***************
*** 511,518 ****
length = max_length;

! if (_PyString_Resize(&RetVal, length) == -1) {
! RetVal = NULL;
goto error;
- }
self->zst.next_out = (unsigned char *)PyString_AS_STRING(RetVal) \
+ old_length;
--- 506,511 ----
length = max_length;

! if (_PyString_Resize(&RetVal, length) < 0)
goto error;
self->zst.next_out = (unsigned char *)PyString_AS_STRING(RetVal) \
+ old_length;
***************
*** 562,567 ****
}

! if (_PyString_Resize(&RetVal, self->zst.total_out - start_total_out) < 0)
! RetVal = NULL;

error:
--- 555,559 ----
}

! _PyString_Resize(&RetVal, self->zst.total_out - start_total_out);

error:
***************
*** 613,620 ****
so extend the output buffer and try again */
while (err == Z_OK && self->zst.avail_out == 0) {
! if (_PyString_Resize(&RetVal, length << 1) == -1) {
! RetVal = NULL;
goto error;
- }
self->zst.next_out = (unsigned char *)PyString_AS_STRING(RetVal) \
+ length;
--- 605,610 ----
so extend the output buffer and try again */
while (err == Z_OK && self->zst.avail_out == 0) {
! if (_PyString_Resize(&RetVal, length << 1) < 0)
goto error;
self->zst.next_out = (unsigned char *)PyString_AS_STRING(RetVal) \
+ length;
***************
*** 652,657 ****
}

! if (_PyString_Resize(&RetVal, self->zst.total_out - start_total_out) < 0)
! RetVal = NULL;

error:
--- 642,646 ----
}

! _PyString_Resize(&RetVal, self->zst.total_out - start_total_out);

error: