https://github.com/python/cpython/commit/aadda87b3d3d99cb9e8c8791bb9715a3f0209195
commit: aadda87b3d3d99cb9e8c8791bb9715a3f0209195
branch: main
author: tigerding <[email protected]>
committer: gpshead <[email protected]>
date: 2025-05-20T20:36:04Z
summary:
gh-134209: use heap-allocated memory in `_curses.window.{instr,getstr}`
(GH-134283)
* made curses buffer heap allocated instead of stack
* change docs to explicitly mention the max buffer size
* changing GetStr() function to behave similarly too
* Update Doc/library/curses.rst
* Update instr with proper return error handling
* Update Modules/_cursesmodule.c
* change to strlen and better memory safety
* change from const int to Py_ssize_t
* add mem allocation guard
* update versionchanged to mention it was an increase.
* explicitly use versionchanged 3.14 as that is its own branch now.
TESTED: `python -m test -u curses test_curses`
---------
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Gregory P. Smith <[email protected]>
Co-authored-by: Bénédikt Tran <[email protected]>
files:
A Misc/NEWS.d/next/Library/2025-05-19-20-59-06.gh-issue-134209.anhTcF.rst
M Doc/library/curses.rst
M Modules/_cursesmodule.c
diff --git a/Doc/library/curses.rst b/Doc/library/curses.rst
index 137504c51b4358..5ec23b61396773 100644
--- a/Doc/library/curses.rst
+++ b/Doc/library/curses.rst
@@ -988,6 +988,10 @@ the following methods and attributes:
window.getstr(y, x, n)
Read a bytes object from the user, with primitive line editing capacity.
+ The maximum value for *n* is 2047.
+
+ .. versionchanged:: 3.14
+ The maximum value for *n* was increased from 1023 to 2047.
.. method:: window.getyx()
@@ -1079,6 +1083,10 @@ the following methods and attributes:
current cursor position, or at *y*, *x* if specified. Attributes are
stripped
from the characters. If *n* is specified, :meth:`instr` returns a string
at most *n* characters long (exclusive of the trailing NUL).
+ The maximum value for *n* is 2047.
+
+ .. versionchanged:: 3.14
+ The maximum value for *n* was increased from 1023 to 2047.
.. method:: window.is_linetouched(line)
diff --git
a/Misc/NEWS.d/next/Library/2025-05-19-20-59-06.gh-issue-134209.anhTcF.rst
b/Misc/NEWS.d/next/Library/2025-05-19-20-59-06.gh-issue-134209.anhTcF.rst
new file mode 100644
index 00000000000000..f985872f3c975e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-05-19-20-59-06.gh-issue-134209.anhTcF.rst
@@ -0,0 +1,3 @@
+:mod:`curses`: The :meth:`curses.window.instr` and :meth:`curses.window.getstr`
+methods now allocate their internal buffer on the heap instead of the stack;
+in addition, the max buffer size is increased from 1023 to 2047.
diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index 2e6ec822e2d5b6..5e1eccee3e4a89 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -1816,7 +1816,7 @@ _curses.window.getstr
x: int
X-coordinate.
]
- n: int = 1023
+ n: int = 2047
Maximal number of characters.
/
@@ -1829,62 +1829,80 @@ PyCursesWindow_GetStr(PyObject *op, PyObject *args)
PyCursesWindowObject *self = _PyCursesWindowObject_CAST(op);
int x, y, n;
- char rtn[1024]; /* This should be big enough.. I hope */
- int rtn2;
+ int rtn;
+
+ /* could make the buffer size larger/dynamic */
+ Py_ssize_t max_buf_size = 2048;
+ PyObject *result = PyBytes_FromStringAndSize(NULL, max_buf_size);
+ if (result == NULL)
+ return NULL;
+ char *buf = PyBytes_AS_STRING(result);
switch (PyTuple_Size(args)) {
case 0:
Py_BEGIN_ALLOW_THREADS
- rtn2 = wgetnstr(self->win,rtn, 1023);
+ rtn = wgetnstr(self->win, buf, max_buf_size - 1);
Py_END_ALLOW_THREADS
break;
case 1:
if (!PyArg_ParseTuple(args,"i;n", &n))
- return NULL;
+ goto error;
if (n < 0) {
PyErr_SetString(PyExc_ValueError, "'n' must be nonnegative");
- return NULL;
+ goto error;
}
Py_BEGIN_ALLOW_THREADS
- rtn2 = wgetnstr(self->win, rtn, Py_MIN(n, 1023));
+ rtn = wgetnstr(self->win, buf, Py_MIN(n, max_buf_size - 1));
Py_END_ALLOW_THREADS
break;
case 2:
if (!PyArg_ParseTuple(args,"ii;y,x",&y,&x))
- return NULL;
+ goto error;
Py_BEGIN_ALLOW_THREADS
#ifdef STRICT_SYSV_CURSES
- rtn2 = wmove(self->win,y,x)==ERR ? ERR : wgetnstr(self->win, rtn,
1023);
+ rtn = wmove(self->win,y,x)==ERR ? ERR : wgetnstr(self->win, rtn,
max_buf_size - 1);
#else
- rtn2 = mvwgetnstr(self->win,y,x,rtn, 1023);
+ rtn = mvwgetnstr(self->win,y,x,buf, max_buf_size - 1);
#endif
Py_END_ALLOW_THREADS
break;
case 3:
if (!PyArg_ParseTuple(args,"iii;y,x,n", &y, &x, &n))
- return NULL;
+ goto error;
if (n < 0) {
PyErr_SetString(PyExc_ValueError, "'n' must be nonnegative");
- return NULL;
+ goto error;
}
#ifdef STRICT_SYSV_CURSES
Py_BEGIN_ALLOW_THREADS
- rtn2 = wmove(self->win,y,x)==ERR ? ERR :
- wgetnstr(self->win, rtn, Py_MIN(n, 1023));
+ rtn = wmove(self->win,y,x)==ERR ? ERR :
+ wgetnstr(self->win, rtn, Py_MIN(n, max_buf_size - 1));
Py_END_ALLOW_THREADS
#else
Py_BEGIN_ALLOW_THREADS
- rtn2 = mvwgetnstr(self->win, y, x, rtn, Py_MIN(n, 1023));
+ rtn = mvwgetnstr(self->win, y, x, buf, Py_MIN(n, max_buf_size - 1));
Py_END_ALLOW_THREADS
#endif
break;
default:
PyErr_SetString(PyExc_TypeError, "getstr requires 0 to 3 arguments");
+ goto error;
+ }
+
+ if (rtn == ERR) {
+ Py_DECREF(result);
+ return Py_GetConstant(Py_CONSTANT_EMPTY_BYTES);
+ }
+
+ if (_PyBytes_Resize(&result, strlen(buf)) < 0) {
return NULL;
}
- if (rtn2 == ERR)
- rtn[0] = 0;
- return PyBytes_FromString(rtn);
+
+ return result;
+
+error:
+ Py_DECREF(result);
+ return NULL;
}
/*[clinic input]
@@ -2023,7 +2041,7 @@ _curses.window.instr
x: int
X-coordinate.
]
- n: int = 1023
+ n: int = 2047
Maximal number of characters.
/
@@ -2040,43 +2058,61 @@ PyCursesWindow_InStr(PyObject *op, PyObject *args)
PyCursesWindowObject *self = _PyCursesWindowObject_CAST(op);
int x, y, n;
- char rtn[1024]; /* This should be big enough.. I hope */
- int rtn2;
+ int rtn;
+
+ /* could make the buffer size larger/dynamic */
+ Py_ssize_t max_buf_size = 2048;
+ PyObject *result = PyBytes_FromStringAndSize(NULL, max_buf_size);
+ if (result == NULL)
+ return NULL;
+ char *buf = PyBytes_AS_STRING(result);
switch (PyTuple_Size(args)) {
case 0:
- rtn2 = winnstr(self->win,rtn, 1023);
+ rtn = winnstr(self->win, buf, max_buf_size - 1);
break;
case 1:
if (!PyArg_ParseTuple(args,"i;n", &n))
- return NULL;
+ goto error;
if (n < 0) {
PyErr_SetString(PyExc_ValueError, "'n' must be nonnegative");
- return NULL;
+ goto error;
}
- rtn2 = winnstr(self->win, rtn, Py_MIN(n, 1023));
+ rtn = winnstr(self->win, buf, Py_MIN(n, max_buf_size - 1));
break;
case 2:
if (!PyArg_ParseTuple(args,"ii;y,x",&y,&x))
- return NULL;
- rtn2 = mvwinnstr(self->win,y,x,rtn,1023);
+ goto error;
+ rtn = mvwinnstr(self->win, y, x, buf, max_buf_size - 1);
break;
case 3:
if (!PyArg_ParseTuple(args, "iii;y,x,n", &y, &x, &n))
- return NULL;
+ goto error;
if (n < 0) {
PyErr_SetString(PyExc_ValueError, "'n' must be nonnegative");
- return NULL;
+ goto error;
}
- rtn2 = mvwinnstr(self->win, y, x, rtn, Py_MIN(n,1023));
+ rtn = mvwinnstr(self->win, y, x, buf, Py_MIN(n, max_buf_size - 1));
break;
default:
PyErr_SetString(PyExc_TypeError, "instr requires 0 or 3 arguments");
+ goto error;
+ }
+
+ if (rtn == ERR) {
+ Py_DECREF(result);
+ return Py_GetConstant(Py_CONSTANT_EMPTY_BYTES);
+ }
+
+ if (_PyBytes_Resize(&result, strlen(buf)) < 0) {
return NULL;
}
- if (rtn2 == ERR)
- rtn[0] = 0;
- return PyBytes_FromString(rtn);
+
+ return result;
+
+error:
+ Py_DECREF(result);
+ return NULL;
}
/*[clinic input]
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