(Merge 3.1) Issue #12175: FileIO.readall() now raises a ValueError instead of

an IOError if the file is closed.

Lib/test/test_io.py

@@ -2505,6 +2505,8 @@ class MiscIOTest(unittest.TestCase):
             self.assertRaises(ValueError, f.read)
             if hasattr(f, "read1"):
                 self.assertRaises(ValueError, f.read1, 1024)
+            if hasattr(f, "readall"):
+                self.assertRaises(ValueError, f.readall)
             if hasattr(f, "readinto"):
                 self.assertRaises(ValueError, f.readinto, bytearray(1024))
             self.assertRaises(ValueError, f.readline)

Misc/NEWS

@@ -731,6 +731,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #12175: FileIO.readall() now raises a ValueError instead of an IOError
+  if the file is closed.
+
 - Issue #10916: mmap should not segfault when a file is mapped using 0 as length
   and a non-zero offset, and an attempt to read past the end of file is made
   (IndexError is raised instead).  Patch by Ross Lagerwall.

Modules/_io/fileio.c

@@ -583,6 +583,8 @@ fileio_readall(fileio *self)
     Py_ssize_t total = 0;
     int n;
 
+    if (self->fd < 0)
+        return err_closed();
     if (!_PyVerify_fd(self->fd))
         return PyErr_SetFromErrno(PyExc_IOError);