Fix 1.4.x branch so that it also does not add the metadata info to the dtype pickle unless it has to. This will allow 1.4.x pickles to be compatible with 1.3.x pickles.

1 files changed, 12 insertions, 10 deletions

diff --git a/numpy/core/src/multiarray/descriptor.c b/numpy/core/src/multiarray/descriptor.c
index 3c67a6b32..fefc1bb28 100644
--- a/numpy/core/src/multiarray/descriptor.c
+++ b/numpy/core/src/multiarray/descriptor.c
@@ -1641,8 +1641,18 @@ arraydescr_reduce(PyArray_Descr *self, PyObject *NPY_UNUSED(args))
             endian = '>';
         }
     }
-    state = PyTuple_New(9);
-    PyTuple_SET_ITEM(state, 0, PyInt_FromLong(version));
+
+    if (self->metadata) {
+        state = PyTuple_New(9);
+        PyTuple_SET_ITEM(state, 0, PyInt_FromLong(version));
+        Py_INCREF(self->metadata);
+        PyTuple_SET_ITEM(state, 8, self->metadata);
+    }
+    else {
+        state = PyTuple_New(8);
+        PyTuple_SET_ITEM(state, 0, PyInt_FromLong(3));
+    }
+
     PyTuple_SET_ITEM(state, 1, PyString_FromFormat("%c", endian));
     PyTuple_SET_ITEM(state, 2, arraydescr_subdescr_get(self));
     if (self->names) {
@@ -1670,14 +1680,6 @@ arraydescr_reduce(PyArray_Descr *self, PyObject *NPY_UNUSED(args))
     PyTuple_SET_ITEM(state, 5, PyInt_FromLong(elsize));
     PyTuple_SET_ITEM(state, 6, PyInt_FromLong(alignment));
     PyTuple_SET_ITEM(state, 7, PyInt_FromLong(self->hasobject));
-    if (self->metadata) {
-        Py_INCREF(self->metadata);
-        PyTuple_SET_ITEM(state, 8, self->metadata);
-    }
-    else {
-        PyTuple_SET_ITEM(state, 8, Py_None);
-        Py_INCREF(Py_None);
-    }
 
     PyTuple_SET_ITEM(ret, 2, state);
     return ret;