Issue #16367: Fix FileIO.readall() on Windows for files larger than 2 GB
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 5411665..7fe2454 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -530,7 +530,7 @@
{
PyObject *result;
Py_ssize_t total = 0;
- int n;
+ Py_ssize_t n;
if (self->fd < 0)
return err_closed();
@@ -563,9 +563,18 @@
}
Py_BEGIN_ALLOW_THREADS
errno = 0;
+ n = newsize - total;
+#if defined(MS_WIN64) || defined(MS_WINDOWS)
+ if (n > INT_MAX)
+ n = INT_MAX;
n = read(self->fd,
PyBytes_AS_STRING(result) + total,
- newsize - total);
+ (int)n);
+#else
+ n = read(self->fd,
+ PyBytes_AS_STRING(result) + total,
+ n);
+#endif
Py_END_ALLOW_THREADS
if (n == 0)
break;