Fix py::object copied without GIL held

jbarlow83 · jbarlow83 · commit 9fdb4740e0d9 · 2022-01-23T14:43:32.000-08:00
Identified by @rwgk. Closes #295.
diff --git a/src/qpdf/mmap_inputsource-inl.h b/src/qpdf/mmap_inputsource-inl.h
@@ -41,11 +41,13 @@
 class MmapInputSource : public InputSource {
 public:
     MmapInputSource(
-        py::object stream, const std::string &description, bool close_stream)
-        : InputSource(), stream(stream), close_stream(close_stream)
+        const py::object &stream, const std::string &description, bool close_stream)
+        : InputSource(), close_stream(close_stream)
     {
         py::gil_scoped_acquire acquire;
-        py::int_ fileno  = stream.attr("fileno")();
+        this->stream = stream;
+
+        py::int_ fileno  = this->stream.attr("fileno")();
         int fd           = fileno;
         auto mmap_module = py::module_::import("mmap");
         auto mmap_fn     = mmap_module.attr("mmap");
diff --git a/src/qpdf/qpdf_inputsource-inl.h b/src/qpdf/qpdf_inputsource-inl.h
@@ -27,13 +27,14 @@
 
 class PythonStreamInputSource : public InputSource {
 public:
-    PythonStreamInputSource(py::object stream, std::string name, bool close)
-        : stream(stream), name(name), close(close)
+    PythonStreamInputSource(const py::object &stream, std::string name, bool close)
+        : name(name), close(close)
     {
         py::gil_scoped_acquire gil;
-        if (!stream.attr("readable")().cast<bool>())
+        this->stream = stream;
+        if (!this->stream.attr("readable")().cast<bool>())
             throw py::value_error("not readable");
-        if (!stream.attr("seekable")().cast<bool>())
+        if (!this->stream.attr("seekable")().cast<bool>())
             throw py::value_error("not seekable");
     }
     virtual ~PythonStreamInputSource()
