Split rawSetRandomInteger out from rawRandomInteger

We already do this for random QQ's.  This will prevent us from
leaking a ZZ and also allow us to throw errors.

Author: d-torrance

M2/Macaulay2/e/ZZ.cpp

@@ -67,7 +67,12 @@ std::pair<bool, long> RingZZ::coerceToLongInteger(ring_elem a) const
                                mpz_get_si(a.get_mpz()));
 }
 
-ring_elem RingZZ::random() const { return ring_elem(rawRandomInteger(nullptr)); }
+ring_elem RingZZ::random() const {
+  mpz_ptr result = new_elem();
+  rawSetRandomInteger(result, nullptr);
+  mpz_reallocate_limbs(result);
+  return ring_elem(result);
+}
 
 void RingZZ::elem_text_out(buffer &o,
                            const ring_elem ap,

M2/Macaulay2/e/aring-zz-gmp.hpp

@@ -195,8 +195,7 @@ class ARingZZGMP : public SimpleARing<ARingZZGMP>
   void swap(ElementType& a, ElementType& b) const { mpz_swap(&a, &b); }
   void random(ElementType& result) const
   {
-    // TODO: this leaks a gmp_ZZ
-    mpz_set(&result, rawRandomInteger(nullptr));
+    rawSetRandomInteger(&result, nullptr);
   }
   /** @} */
 

M2/Macaulay2/e/interface/random.cpp

@@ -53,11 +53,9 @@ int32_t rawRandomInt(int32_t max)
   return RandomSeed % max;
 }
 
-gmp_ZZ rawRandomInteger(gmp_ZZ maxN)
+void rawSetRandomInteger(mpz_ptr result, gmp_ZZ maxN)
 /* if height is the null pointer, use the default height */
 {
-  mpz_ptr result = getmemstructtype(mpz_ptr);
-  mpz_init(result);
   if (maxN == nullptr)
     mpz_urandomm(result, state, maxHeight);
   else if (1 != mpz_sgn(maxN))
@@ -66,6 +64,16 @@ gmp_ZZ rawRandomInteger(gmp_ZZ maxN)
     }
   else
     mpz_urandomm(result, state, maxN);
+}
+
+gmp_ZZ rawRandomInteger(gmp_ZZ maxN)
+/* if height is the null pointer, use the default height */
+{
+  mpz_ptr result = getmemstructtype(mpz_ptr);
+  mpz_init(result);
+
+  rawSetRandomInteger(result, maxN);
+
   mpz_reallocate_limbs(result);
   return result;
 }

M2/Macaulay2/e/interface/random.h

@@ -25,6 +25,9 @@ unsigned long rawRandomULong(unsigned long max);
 int32_t rawRandomInt(int32_t max);
 /* generate a random number in the range 0..max-1 */
 
+void rawSetRandomInteger(mpz_ptr result, gmp_ZZ maxN);
+/* if height is the null pointer, use the default height */
+
 gmp_ZZ rawRandomInteger(gmp_ZZ maxN);
 /* if height is the null pointer, use the default height */