bpo-139145: fix spinning event loop in tkinter

Author: Michiel Jan Laurens de Hoon

Modules/_tkinter.c

@@ -3356,7 +3356,9 @@ static int stdin_ready = 0;
 static void
 MyFileProc(void *clientData, int mask)
 {
+    int *tfile = clientData;
     stdin_ready = 1;
+    Tcl_DeleteFileHandler(*tfile);
 }
 #endif
 
@@ -3373,7 +3375,7 @@ EventHook(void)
     errorInCmd = 0;
 #ifndef MS_WINDOWS
     tfile = fileno(stdin);
-    Tcl_CreateFileHandler(tfile, TCL_READABLE, MyFileProc, NULL);
+    Tcl_CreateFileHandler(tfile, TCL_READABLE, MyFileProc, &tfile);
 #endif
     while (!errorInCmd && !stdin_ready) {
         int result;
@@ -3398,9 +3400,6 @@ EventHook(void)
         if (result < 0)
             break;
     }
-#ifndef MS_WINDOWS
-    Tcl_DeleteFileHandler(tfile);
-#endif
     if (errorInCmd) {
         errorInCmd = 0;
         PyErr_SetRaisedException(excInCmd);