MAINT: Express PyArray_DescrAlignConverter in terms of _convert_from_any

This also fixes an inconsequential bug, meaning the following (scary) code no longer asserts
```
np.typeDict['mypoint`] = [('a', 'i1'), ('b', 'i2')]
assert np.dtype('mypoint', align=True).isalignedstruct
```

I'm not going to legitimize this sort of thing with a test though.

1 files changed, 33 insertions, 62 deletions

diff --git a/numpy/core/src/multiarray/descriptor.c b/numpy/core/src/multiarray/descriptor.c
index 0063131e4..8654d7e3d 100644
--- a/numpy/core/src/multiarray/descriptor.c
+++ b/numpy/core/src/multiarray/descriptor.c
@@ -39,24 +39,29 @@
 
 static PyObject *typeDict = NULL;   /* Must be explicitly loaded */
 
+/*
+ * Generate a vague error message when a function returned NULL but forgot
+ * to set an exception. We should aim to remove this eventually.
+ */
+static void
+_report_generic_error(void) {
+    PyErr_SetString(PyExc_TypeError, "data type not understood");
+}
+
 static PyArray_Descr *
 _use_inherit(PyArray_Descr *type, PyObject *newobj, int *errflag);
 
 static PyArray_Descr *
+_convert_from_any(PyObject *obj, int align);
+
+static PyArray_Descr *
 _arraydescr_run_converter(PyObject *arg, int align)
 {
-    PyArray_Descr *type = NULL;
-    if (align) {
-        if (PyArray_DescrAlignConverter(arg, &type) == NPY_FAIL) {
-            return NULL;
-        }
-    }
-    else {
-        if (PyArray_DescrConverter(arg, &type) == NPY_FAIL) {
-            return NULL;
-        }
+    PyArray_Descr *type = _convert_from_any(arg, align);
+    /* TODO: fix the `_convert` functions so that this can never happen */
+    if (type == NULL && !PyErr_Occurred()) {
+        _report_generic_error();
     }
-    assert(type != NULL);
     return type;
 }
 
@@ -1399,20 +1404,12 @@ _convert_from_type(PyObject *obj) {
     }
 }
 
-/*
- * Generate a vague error message when a function returned NULL but forgot
- * to set an exception. We should aim to remove this eventually.
- */
-static void
-_report_generic_error(void) {
-    PyErr_SetString(PyExc_TypeError, "data type not understood");
-}
 
 static PyArray_Descr *
-_convert_from_bytes(PyObject *obj);
+_convert_from_bytes(PyObject *obj, int align);
 
 static PyArray_Descr *
-_convert_from_any(PyObject *obj)
+_convert_from_any(PyObject *obj, int align)
 {
     /* default */
     if (obj == Py_None) {
@@ -1439,24 +1436,24 @@ _convert_from_any(PyObject *obj)
             }
             return NULL;
         }
-        PyArray_Descr *ret = _convert_from_any(obj2);
+        PyArray_Descr *ret = _convert_from_any(obj2, align);
         Py_DECREF(obj2);
         return ret;
     }
     else if (PyBytes_Check(obj)) {
-        return _convert_from_bytes(obj);
+        return _convert_from_bytes(obj, align);
     }
     else if (PyTuple_Check(obj)) {
         /* or a tuple */
-        return _convert_from_tuple(obj, 0);
+        return _convert_from_tuple(obj, align);
     }
     else if (PyList_Check(obj)) {
         /* or a list */
-        return _convert_from_array_descr(obj, 0);
+        return _convert_from_array_descr(obj, align);
     }
     else if (PyDict_Check(obj) || PyDictProxy_Check(obj)) {
         /* or a dictionary */
-        return _convert_from_dict(obj, 0);
+        return _convert_from_dict(obj, align);
     }
     else if (PyArray_Check(obj)) {
         _report_generic_error();
@@ -1503,16 +1500,13 @@ _convert_from_any(PyObject *obj)
 NPY_NO_EXPORT int
 PyArray_DescrConverter(PyObject *obj, PyArray_Descr **at)
 {
-    *at = _convert_from_any(obj);
-    if (*at == NULL && !PyErr_Occurred()) {
-        _report_generic_error();
-    }
+    *at = _arraydescr_run_converter(obj, 0);
     return (*at) ? NPY_SUCCEED : NPY_FAIL;
 }
 
 /** Convert a bytestring specification into a dtype */
 static PyArray_Descr *
-_convert_from_bytes(PyObject *obj)
+_convert_from_bytes(PyObject *obj, int align)
 {
     /* Check for a string typecode. */
     char *type = NULL;
@@ -1528,7 +1522,7 @@ _convert_from_bytes(PyObject *obj)
 
     /* check for commas present or first (or second) element a digit */
     if (_check_for_commastring(type, len)) {
-        return _convert_from_commastring(obj, 0);
+        return _convert_from_commastring(obj, align);
     }
 
     /* Process the endian character. '|' is replaced by '='*/
@@ -1661,7 +1655,11 @@ _convert_from_bytes(PyObject *obj)
                 }
             }
         }
-        return _convert_from_any(item);
+        /*
+         * Probably only ever dispatches to `_convert_from_type`, but who
+         * knows what users are injecting into `np.typeDict`.
+         */
+        return _convert_from_any(item, align);
     }
 
     if (PyDataType_ISUNSIZED(ret) && ret->elsize != elsize) {
@@ -2858,35 +2856,8 @@ arraydescr_setstate(PyArray_Descr *self, PyObject *args)
 NPY_NO_EXPORT int
 PyArray_DescrAlignConverter(PyObject *obj, PyArray_Descr **at)
 {
-    if (PyDict_Check(obj) || PyDictProxy_Check(obj)) {
-        *at =  _convert_from_dict(obj, 1);
-    }
-    else if (PyBytes_Check(obj)) {
-        *at = _convert_from_commastring(obj, 1);
-    }
-    else if (PyUnicode_Check(obj)) {
-        PyObject *tmp;
-        tmp = PyUnicode_AsASCIIString(obj);
-        *at = _convert_from_commastring(tmp, 1);
-        Py_DECREF(tmp);
-    }
-    else if (PyTuple_Check(obj)) {
-        *at = _convert_from_tuple(obj, 1);
-    }
-    else if (PyList_Check(obj)) {
-        *at = _convert_from_array_descr(obj, 1);
-    }
-    else {
-        return PyArray_DescrConverter(obj, at);
-    }
-    if (*at == NULL) {
-        if (!PyErr_Occurred()) {
-            PyErr_SetString(PyExc_ValueError,
-                    "data-type-descriptor not understood");
-        }
-        return NPY_FAIL;
-    }
-    return NPY_SUCCEED;
+    *at = _arraydescr_run_converter(obj, 1);
+    return (*at) ? NPY_SUCCEED : NPY_FAIL;
 }
 
 /*NUMPY_API