BUG: Make n a long int for np.random.multinomial

Author: thalassemia

numpy/random/mtrand.pyx

@@ -4253,7 +4253,7 @@ cdef class RandomState:
         x.shape = tuple(final_shape)
         return x
 
-    def multinomial(self, np.npy_intp n, object pvals, size=None):
+    def multinomial(self, long n, object pvals, size=None):
         """
         multinomial(n, pvals, size=None)
 

numpy/random/tests/test_randomstate.py

@@ -183,6 +183,9 @@ def test_multinomial_pvals_float32(self):
         with pytest.raises(ValueError, match=match):
             random.multinomial(1, pvals)
 
+    def test_multinomial_n_float(self):
+        # Non-index integer types should gracefully truncate floats
+        random.multinomial(100.5, [0.2, 0.8])
 
 class TestSetState:
     def setup_method(self):