Fixes issue #12268: File readline, readlines and read() or readall() methods

no longer lose data when an underlying read system call is interrupted.
IOError is no longer raised due to a read system call returning EINTR
from within these methods.

1 files changed, 19 insertions, 4 deletions

diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
index b30bbb6..dd052ae 100644
--- a/Modules/_io/iobase.c
+++ b/Modules/_io/iobase.c
@@ -474,11 +474,15 @@ iobase_readline(PyObject *self, PyObject *args)
         PyObject *b;
 
         if (has_peek) {
-            _Py_IDENTIFIER(peek);
             PyObject *readahead = _PyObject_CallMethodId(self, &PyId_peek, "i", 1);
-
-            if (readahead == NULL)
+            if (readahead == NULL) {
+                /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
+                   when EINTR occurs so we needn't do it ourselves. */
+                if (_PyIO_trap_eintr()) {
+                    continue;
+                }
                 goto fail;
+            }
             if (!PyBytes_Check(readahead)) {
                 PyErr_Format(PyExc_IOError,
                              "peek() should have returned a bytes object, "
@@ -511,8 +515,14 @@ iobase_readline(PyObject *self, PyObject *args)
         }
 
         b = _PyObject_CallMethodId(self, &PyId_read, "n", nreadahead);
-        if (b == NULL)
+        if (b == NULL) {
+            /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
+               when EINTR occurs so we needn't do it ourselves. */
+            if (_PyIO_trap_eintr()) {
+                continue;
+            }
             goto fail;
+        }
         if (!PyBytes_Check(b)) {
             PyErr_Format(PyExc_IOError,
                          "read() should have returned a bytes object, "
@@ -827,6 +837,11 @@ rawiobase_readall(PyObject *self, PyObject *args)
         PyObject *data = _PyObject_CallMethodId(self, &PyId_read,
                                                 "i", DEFAULT_BUFFER_SIZE);
         if (!data) {
+            /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
+               when EINTR occurs so we needn't do it ourselves. */
+            if (_PyIO_trap_eintr()) {
+                continue;
+            }
             Py_DECREF(chunks);
             return NULL;
         }