--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src_classic/helper-fileobj.i	Mon Sep 15 11:37:51 2025 +0200
@@ -0,0 +1,113 @@
+%{
+//-------------------------------------
+// fz_output for Python file objects
+//-------------------------------------
+static void
+JM_bytesio_write(fz_context *ctx, void *opaque, const void *data, size_t len)
+{  // bio.write(bytes object)
+    PyObject *bio = opaque, *b, *name, *rc;
+    fz_try(ctx){
+        b = PyBytes_FromStringAndSize((const char *) data, (Py_ssize_t) len);
+        name = PyUnicode_FromString("write");
+        PyObject_CallMethodObjArgs(bio, name, b, NULL);
+        rc = PyErr_Occurred();
+        if (rc) {
+            RAISEPY(ctx, "could not write to Py file obj", rc);
+        }
+    }
+    fz_always(ctx) {
+        Py_XDECREF(b);
+        Py_XDECREF(name);
+        Py_XDECREF(rc);
+        PyErr_Clear();
+    }
+    fz_catch(ctx) {
+        fz_rethrow(ctx);
+    }
+}
+
+static void
+JM_bytesio_truncate(fz_context *ctx, void *opaque)
+{  // bio.truncate(bio.tell()) !!!
+    PyObject *bio = opaque, *trunc = NULL, *tell = NULL, *rctell= NULL, *rc = NULL;
+    fz_try(ctx) {
+        trunc = PyUnicode_FromString("truncate");
+        tell = PyUnicode_FromString("tell");
+        rctell = PyObject_CallMethodObjArgs(bio, tell, NULL);
+        PyObject_CallMethodObjArgs(bio, trunc, rctell, NULL);
+        rc = PyErr_Occurred();
+        if (rc) {
+            RAISEPY(ctx, "could not truncate Py file obj", rc);
+        }
+    }
+    fz_always(ctx) {
+        Py_XDECREF(tell);
+        Py_XDECREF(trunc);
+        Py_XDECREF(rc);
+        Py_XDECREF(rctell);
+        PyErr_Clear();
+    }
+    fz_catch(ctx) {
+        fz_rethrow(ctx);
+    }
+}
+
+static int64_t
+JM_bytesio_tell(fz_context *ctx, void *opaque)
+{  // returns bio.tell() -> int
+    PyObject *bio = opaque, *rc = NULL, *name = NULL;
+    int64_t pos = 0;
+    fz_try(ctx) {
+        name = PyUnicode_FromString("tell");
+        rc = PyObject_CallMethodObjArgs(bio, name, NULL);
+        if (!rc) {
+            RAISEPY(ctx, "could not tell Py file obj", PyErr_Occurred());
+        }
+        pos = (int64_t) PyLong_AsUnsignedLongLong(rc);
+    }
+    fz_always(ctx) {
+        Py_XDECREF(name);
+        Py_XDECREF(rc);
+        PyErr_Clear();
+    }
+    fz_catch(ctx) {
+        fz_rethrow(ctx);
+    }
+    return pos;
+}
+
+
+static void
+JM_bytesio_seek(fz_context *ctx, void *opaque, int64_t off, int whence)
+{  // bio.seek(off, whence=0)
+    PyObject *bio = opaque, *rc = NULL, *name = NULL, *pos = NULL;
+    fz_try(ctx) {
+        name = PyUnicode_FromString("seek");
+        pos = PyLong_FromUnsignedLongLong((unsigned long long) off);
+        PyObject_CallMethodObjArgs(bio, name, pos, whence, NULL);
+        rc = PyErr_Occurred();
+        if (rc) {
+            RAISEPY(ctx, "could not seek Py file obj", rc);
+        }
+    }
+    fz_always(ctx) {
+        Py_XDECREF(rc);
+        Py_XDECREF(name);
+        Py_XDECREF(pos);
+        PyErr_Clear();
+    }
+    fz_catch(ctx) {
+        fz_rethrow(ctx);
+    }
+}
+
+fz_output *
+JM_new_output_fileptr(fz_context *ctx, PyObject *bio)
+{
+    fz_output *out = fz_new_output(ctx, 0, bio, JM_bytesio_write, NULL, NULL);
+    out->seek = JM_bytesio_seek;
+    out->tell = JM_bytesio_tell;
+    out->truncate = JM_bytesio_truncate;
+    return out;
+}
+%}