Issue #8124: PySys_WriteStdout() and PySys_WriteStderr() don't execute

indirectly Python signal handlers anymore because mywrite() ignores exceptions
(KeyboardInterrupt).

diff --git a/Misc/NEWS b/Misc/NEWS
index 3ccc011a9713c805376b726fec7b9590425aa86e..0be862636f1b86b6584f42bb5b613e867bbf3cb1 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,10 @@ What's New in Python 3.2 Alpha 1?
 Core and Builtins
 -----------------
 
+- Issue #8124: PySys_WriteStdout() and PySys_WriteStderr() don't execute
+  indirectly Python signal handlers anymore because mywrite() ignores
+  exceptions (KeyboardInterrupt)
+
 - Issue #8092: Fix PyUnicode_EncodeUTF8() to support error handler producing
   unicode string (eg. backslashreplace)
 

diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 490577d3e2640e2b0a19300a330590a0bd20907c..82673695840fbebc18744da11e949559d7daea45 100644 (file)
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1763,6 +1763,45 @@ PySys_SetArgv(int argc, wchar_t **argv)
        Py_DECREF(av);
 }
 
+/* Reimplementation of PyFile_WriteString() no calling indirectly
+   PyErr_CheckSignals(): avoid the call to PyObject_Str(). */
+
+static int
+sys_pyfile_write(const char *text, PyObject *file)
+{
+       PyObject *unicode = NULL, *writer = NULL, *args = NULL, *result = NULL;
+       int err;
+
+       unicode = PyUnicode_FromString(text);
+       if (unicode == NULL)
+               goto error;
+
+       writer = PyObject_GetAttrString(file, "write");
+       if (writer == NULL)
+               goto error;
+
+       args = PyTuple_Pack(1, unicode);
+       if (args == NULL)
+               goto error;
+
+       result = PyEval_CallObject(writer, args);
+       if (result == NULL) {
+               goto error;
+       } else {
+               err = 0;
+               goto finally;
+       }
+
+error:
+       err = -1;
+finally:
+       Py_XDECREF(unicode);
+       Py_XDECREF(writer);
+       Py_XDECREF(args);
+       Py_XDECREF(result);
+       return err;
+}
+
 
 /* APIs to write to sys.stdout or sys.stderr using a printf-like interface.
    Adapted from code submitted by Just van Rossum.
@@ -1774,6 +1813,10 @@ PySys_SetArgv(int argc, wchar_t **argv)
       there is a problem, they write to the real (C level) stdout or stderr;
       no exceptions are raised.
 
+      PyErr_CheckSignals() is not called to avoid the execution of the Python
+      signal handlers: they may raise a new exception whereas mywrite() ignores
+      all exceptions.
+
       Both take a printf-style format string as their first argument followed
       by a variable length argument list determined by the format string.
 
@@ -1799,13 +1842,13 @@ mywrite(char *name, FILE *fp, const char *format, va_list va)
        PyErr_Fetch(&error_type, &error_value, &error_traceback);
        file = PySys_GetObject(name);
        written = PyOS_vsnprintf(buffer, sizeof(buffer), format, va);
-       if (PyFile_WriteString(buffer, file) != 0) {
+       if (sys_pyfile_write(buffer, file) != 0) {
                PyErr_Clear();
                fputs(buffer, fp);
        }
        if (written < 0 || (size_t)written >= sizeof(buffer)) {
                const char *truncated = "... truncated";
-               if (PyFile_WriteString(truncated, file) != 0) {
+               if (sys_pyfile_write(truncated, file) != 0) {
                        PyErr_Clear();
                        fputs(truncated, fp);
                }