Fix SF #692416, don't crash interpreter for _tkinter.deletefilehandler

in addition to createfilehandler and creaetetimerhandler.

2 files changed, 17 insertions, 1 deletions

diff --git a/Misc/NEWS b/Misc/NEWS
index 5bf335a5a9..fa1b8f9fc3 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -24,6 +24,10 @@ Core and builtins
 Extension modules
 -----------------
 
+- Using createfilehandler, deletefilehandler, createtimerhandler functions
+  on Tkinter.tkinter (_tkinter module) no longer crashes the interpreter.
+  See SF bug #692416.
+
 - Modified the fcntl.ioctl() function to allow modification of a passed
   mutable buffer (for details see the reference documentation).
 
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 813d27c793..100e06f227 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -2243,7 +2243,19 @@ Tkapp_DeleteFileHandler(PyObject *self, PyObject *args)
 
 	if (!PyArg_ParseTuple(args, "O:deletefilehandler", &file))
 		return NULL;
-	CHECK_TCL_APPARTMENT;
+
+	if (!self && !tcl_lock) {
+		/* We don't have the Tcl lock since Tcl is threaded. */
+		PyErr_SetString(PyExc_RuntimeError,
+				"_tkinter.deletefilehandler not supported "
+				"for threaded Tcl");
+		return NULL;
+	}
+
+	if (self) {
+		CHECK_TCL_APPARTMENT;
+	}
+
 	tfile = PyObject_AsFileDescriptor(file);
 	if (tfile < 0)
 		return NULL;