Merge #18510: fuzz: Add CScriptNum::getint coverage

faa64af fuzz: Add CScriptNum::getint coverage (MarcoFalke)

Pull request description:

  Add coverage for

  * https://marcofalke.github.io/btc_cov/fuzz.coverage/src/script/script.h.gcov.html#311
  * https://marcofalke.github.io/btc_cov/fuzz.coverage/src/script/script.h.gcov.html#511

ACKs for top commit:
  practicalswift:
    ACK faa64af -- more fuzzing coverage is better than less fuzzing coverage :)

Tree-SHA512: 1a66a2edc3740e8c286049f6c27458c59c45b01052e51684eec0e1be63ffcee94b4ba3d41d88ad715ceb3e4754fd997cf03899085982454905e86d0553d58199

Author: MarcoFalke

src/test/fuzz/integer.cpp

@@ -126,9 +126,21 @@ void test_one_input(const std::vector<uint8_t>& buffer)
             assert(parsed_money == i64);
         }
     }
+    if (i32 >= 0 && i32 <= 16) {
+        assert(i32 == CScript::DecodeOP_N(CScript::EncodeOP_N(i32)));
+    }
+
     const std::chrono::seconds seconds{i64};
     assert(count_seconds(seconds) == i64);
 
+    const CScriptNum script_num{i64};
+    (void)script_num.getint();
+    // Avoid negation failure:
+    // script/script.h:332:35: runtime error: negation of -9223372036854775808 cannot be represented in type 'int64_t' (aka 'long'); cast to an unsigned type to negate this value to itself
+    if (script_num != CScriptNum{std::numeric_limits<int64_t>::min()}) {
+        (void)script_num.getvch();
+    }
+
     const arith_uint256 au256 = UintToArith256(u256);
     assert(ArithToUint256(au256) == u256);
     assert(uint256S(au256.GetHex()) == u256);

src/test/fuzz/scriptnum_ops.cpp

@@ -128,6 +128,7 @@ void test_one_input(const std::vector<uint8_t>& buffer)
             script_num &= fuzzed_data_provider.ConsumeIntegral<int64_t>();
             break;
         }
+        (void)script_num.getint();
         // Avoid negation failure:
         // script/script.h:332:35: runtime error: negation of -9223372036854775808 cannot be represented in type 'int64_t' (aka 'long'); cast to an unsigned type to negate this value to itself
         if (script_num != CScriptNum{std::numeric_limits<int64_t>::min()}) {