gh-108996: fix and enable test_msvcrt (#109226)

* Add _testconsole.flush_console_input_buffer() function.
* test_kbhit(), test_getwch() and test_getwche() now call
  flush_console_input_buffer().
* Don't override sys.stdin anymore (not needed).

1 files changed, 69 insertions, 1 deletions

diff --git a/PC/clinic/_testconsole.c.h b/PC/clinic/_testconsole.c.h
index 99cd302..b765889 100644
--- a/PC/clinic/_testconsole.c.h
+++ b/PC/clinic/_testconsole.c.h
@@ -132,6 +132,70 @@ exit:
 
 #endif /* defined(MS_WINDOWS) */
 
+#if defined(MS_WINDOWS)
+
+PyDoc_STRVAR(_testconsole_flush_console_input_buffer__doc__,
+"flush_console_input_buffer($module, /, handle)\n"
+"--\n"
+"\n"
+"Flushes the console input buffer.\n"
+"\n"
+"All input records currently in the input buffer are discarded.");
+
+#define _TESTCONSOLE_FLUSH_CONSOLE_INPUT_BUFFER_METHODDEF    \
+    {"flush_console_input_buffer", _PyCFunction_CAST(_testconsole_flush_console_input_buffer), METH_FASTCALL|METH_KEYWORDS, _testconsole_flush_console_input_buffer__doc__},
+
+static PyObject *
+_testconsole_flush_console_input_buffer_impl(PyObject *module, void *handle);
+
+static PyObject *
+_testconsole_flush_console_input_buffer(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)
+{
+    PyObject *return_value = NULL;
+    #if defined(Py_BUILD_CORE) && !defined(Py_BUILD_CORE_MODULE)
+
+    #define NUM_KEYWORDS 1
+    static struct {
+        PyGC_Head _this_is_not_used;
+        PyObject_VAR_HEAD
+        PyObject *ob_item[NUM_KEYWORDS];
+    } _kwtuple = {
+        .ob_base = PyVarObject_HEAD_INIT(&PyTuple_Type, NUM_KEYWORDS)
+        .ob_item = { &_Py_ID(handle), },
+    };
+    #undef NUM_KEYWORDS
+    #define KWTUPLE (&_kwtuple.ob_base.ob_base)
+
+    #else  // !Py_BUILD_CORE
+    #  define KWTUPLE NULL
+    #endif  // !Py_BUILD_CORE
+
+    static const char * const _keywords[] = {"handle", NULL};
+    static _PyArg_Parser _parser = {
+        .keywords = _keywords,
+        .fname = "flush_console_input_buffer",
+        .kwtuple = KWTUPLE,
+    };
+    #undef KWTUPLE
+    PyObject *argsbuf[1];
+    void *handle;
+
+    args = _PyArg_UnpackKeywords(args, nargs, NULL, kwnames, &_parser, 1, 1, 0, argsbuf);
+    if (!args) {
+        goto exit;
+    }
+    handle = PyLong_AsVoidPtr(args[0]);
+    if (!handle && PyErr_Occurred()) {
+        goto exit;
+    }
+    return_value = _testconsole_flush_console_input_buffer_impl(module, handle);
+
+exit:
+    return return_value;
+}
+
+#endif /* defined(MS_WINDOWS) */
+
 #ifndef _TESTCONSOLE_WRITE_INPUT_METHODDEF
     #define _TESTCONSOLE_WRITE_INPUT_METHODDEF
 #endif /* !defined(_TESTCONSOLE_WRITE_INPUT_METHODDEF) */
@@ -139,4 +203,8 @@ exit:
 #ifndef _TESTCONSOLE_READ_OUTPUT_METHODDEF
     #define _TESTCONSOLE_READ_OUTPUT_METHODDEF
 #endif /* !defined(_TESTCONSOLE_READ_OUTPUT_METHODDEF) */
-/*[clinic end generated code: output=f59fe72cd4e73704 input=a9049054013a1b77]*/
+
+#ifndef _TESTCONSOLE_FLUSH_CONSOLE_INPUT_BUFFER_METHODDEF
+    #define _TESTCONSOLE_FLUSH_CONSOLE_INPUT_BUFFER_METHODDEF
+#endif /* !defined(_TESTCONSOLE_FLUSH_CONSOLE_INPUT_BUFFER_METHODDEF) */
+/*[clinic end generated code: output=5d488564f2500dd9 input=a9049054013a1b77]*/