Issue #9611, #9015: FileIO.read() clamps the length to INT_MAX on Windows.
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 141b6de..b1d492b 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -664,6 +664,10 @@
return fileio_readall(self);
}
+#if defined(MS_WIN64) || defined(MS_WINDOWS)
+ if (size > INT_MAX)
+ size = INT_MAX;
+#endif
bytes = PyBytes_FromStringAndSize(NULL, size);
if (bytes == NULL)
return NULL;
@@ -672,7 +676,11 @@
if (_PyVerify_fd(self->fd)) {
Py_BEGIN_ALLOW_THREADS
errno = 0;
+#if defined(MS_WIN64) || defined(MS_WINDOWS)
+ n = read(self->fd, ptr, (int)size);
+#else
n = read(self->fd, ptr, size);
+#endif
Py_END_ALLOW_THREADS
} else
n = -1;