From f50144ab512d1fad959dc0431fe2652b45c17c9c Mon Sep 17 00:00:00 2001
From: Hood Chatham <roberthoodchatham@gmail.com>
Date: Tue, 4 Jun 2024 09:44:37 -0700
Subject: [PATCH] FIX Check if future is done before trying to set a result on
 it

Otherwise, future raises invalid state error.
Question: should we try to avoid getting to the point where we call this in the
first place??
---
 src/core/jsproxy.c                |  8 ++++++--
 src/py/_pyodide/_future_helper.py | 13 +++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 src/py/_pyodide/_future_helper.py

diff --git a/src/core/jsproxy.c b/src/core/jsproxy.c
index a57af6e56281..0e075d45fb01 100644
--- a/src/core/jsproxy.c
+++ b/src/core/jsproxy.c
@@ -2637,6 +2637,7 @@ wrap_promise(JsVal promise, JsVal done_callback, PyObject* js2py_converter)
 {
   bool success = false;
   PyObject* loop = NULL;
+  PyObject* helpers = NULL;
   PyObject* set_result = NULL;
   PyObject* set_exception = NULL;
 
@@ -2648,9 +2649,11 @@ wrap_promise(JsVal promise, JsVal done_callback, PyObject* js2py_converter)
   result = _PyObject_CallMethodIdNoArgs(loop, &PyId_create_future);
   FAIL_IF_NULL(result);
 
-  set_result = _PyObject_GetAttrId(result, &PyId_set_result);
+  helpers = PyImport_ImportModule("_pyodide._future_helpers");
+  FAIL_IF_NULL(helpers);
+  set_result = Py_XNewRef(PyTuple_GetItem(helpers, 0));
   FAIL_IF_NULL(set_result);
-  set_exception = _PyObject_GetAttrId(result, &PyId_set_exception);
+  set_exception = Py_XNewRef(PyTuple_GetItem(helpers, 1));
   FAIL_IF_NULL(set_exception);
 
   promise = JsvPromise_Resolve(promise);
@@ -2663,6 +2666,7 @@ wrap_promise(JsVal promise, JsVal done_callback, PyObject* js2py_converter)
   success = true;
 finally:
   Py_CLEAR(loop);
+  Py_CLEAR(helpers);
   Py_CLEAR(set_result);
   Py_CLEAR(set_exception);
   if (!success) {
diff --git a/src/py/_pyodide/_future_helper.py b/src/py/_pyodide/_future_helper.py
new file mode 100644
index 000000000000..3d82300f3622
--- /dev/null
+++ b/src/py/_pyodide/_future_helper.py
@@ -0,0 +1,13 @@
+def set_result(fut, val):
+    if fut.done():
+        return
+    fut.set_result(val)
+
+def set_exception(fut, val):
+    if fut.done():
+        return
+    fut.set_result(val)
+
+
+def get_future_resolvers(fut):
+    return (set_result.__get__(fut), set_exception.__get__(fut))