swap checking order for numbers and sequences to handle cases where something that is a sequence, implements a numeric protocol and it fails on conversion to double (also improved error checking for PyFloat_AsDouble)

Author: Matiiss

src_c/math.c

@@ -2280,19 +2280,23 @@ static int
 _vector2_set(pgVector *self, PyObject *xOrSequence, PyObject *y)
 {
     if (xOrSequence) {
-        if (RealNumber_Check(xOrSequence)) {
-            self->coords[0] = PyFloat_AsDouble(xOrSequence);
-            /* scalar constructor. */
-            if (y == NULL) {
-                self->coords[1] = self->coords[0];
+        if (pgVectorCompatible_Check(xOrSequence, self->dim)) {
+            if (!PySequence_AsVectorCoords(xOrSequence, self->coords, 2)) {
+                return -1;
+            }
+            else {
                 return 0;
             }
         }
-        else if (pgVectorCompatible_Check(xOrSequence, self->dim)) {
-            if (!PySequence_AsVectorCoords(xOrSequence, self->coords, 2)) {
+        else if (RealNumber_Check(xOrSequence)) {
+            self->coords[0] = PyFloat_AsDouble(xOrSequence);
+            if (self->coords[0] == -1.0 && PyErr_Occurred()) {
                 return -1;
             }
-            else {
+
+            /* scalar constructor. */
+            if (y == NULL) {
+                self->coords[1] = self->coords[0];
                 return 0;
             }
         }
@@ -2323,6 +2327,9 @@ _vector2_set(pgVector *self, PyObject *xOrSequence, PyObject *y)
 
     if (RealNumber_Check(y)) {
         self->coords[1] = PyFloat_AsDouble(y);
+        if (self->coords[1] == -1.0 && PyErr_Occurred()) {
+            return -1;
+        }
     }
     else {
         goto error;