group: Avoid using infinity field directly in other modules

src/tests_exhaustive.c

@@ -103,9 +103,11 @@ static void test_exhaustive_addition(const secp256k1_ge *group, const secp256k1_
             secp256k1_gej_add_ge_var(&tmp, &groupj[i], &group[j], NULL);
             CHECK(secp256k1_gej_eq_ge_var(&tmp, &group[(i + j) % EXHAUSTIVE_TEST_ORDER]));
             /* add_zinv_var */
-            zless_gej.infinity = groupj[j].infinity;
-            zless_gej.x = groupj[j].x;
-            zless_gej.y = groupj[j].y;
+            if (secp256k1_gej_is_infinity(&groupj[j])) {
+                secp256k1_ge_set_infinity(&zless_gej);
+            } else {
+                secp256k1_ge_set_xy(&zless_gej, &groupj[j].x, &groupj[j].y);
+            }
             secp256k1_gej_add_zinv_var(&tmp, &groupj[i], &zless_gej, &fe_inv);
             CHECK(secp256k1_gej_eq_ge_var(&tmp, &group[(i + j) % EXHAUSTIVE_TEST_ORDER]));
         }
@@ -422,10 +424,8 @@ int main(int argc, char** argv) {
                 secp256k1_ecmult_gen(&ctx->ecmult_gen_ctx, &generatedj, &scalar_i);
                 secp256k1_ge_set_gej(&generated, &generatedj);
 
-                CHECK(group[i].infinity == 0);
-                CHECK(generated.infinity == 0);
-                CHECK(secp256k1_fe_equal(&generated.x, &group[i].x));
-                CHECK(secp256k1_fe_equal(&generated.y, &group[i].y));
+                CHECK(!secp256k1_ge_is_infinity(&group[i]));
+                CHECK(secp256k1_ge_eq_var(&group[i], &generated));
             }
         }