Correctly report numeric overflow and clarify error semantics

Fixes a bug where ReadErrorReason::NotEnoughPrecision was never constructed.

NotEnoughPrecision renamed to NumericValueOverflow for clearer semantics.

Replaced magic decimal threshold with equivalent hex literal (0x80000000000000)
for better readability.

Author: j4r0u53k

Cargo.toml

@@ -5,7 +5,7 @@ name = "shvproto"
 description = "Rust implementation of the SHV protocol"
 license = "MIT"
 repository = "https://github.com/silicon-heaven/libshvproto-rs"
-version = "5.0.1"
+version = "6.0.0"
 edition = "2024"
 
 [dependencies]

src/bin/cp2cp.rs

@@ -63,7 +63,7 @@ fn print_option<T: Display>(n: Option<T>) {
 fn exit_with_result_and_code(result: &ChainPackRpcBlockResult, error: Option<ReadErrorReason>) -> ! {
     let exit_code = error.map_or(CODE_SUCCESS, |error| match error {
         ReadErrorReason::UnexpectedEndOfStream => CODE_NOT_ENOUGH_DATA,
-        ReadErrorReason::NotEnoughPrecision => CODE_READ_ERROR,
+        ReadErrorReason::NumericValueOverflow => CODE_READ_ERROR,
         ReadErrorReason::InvalidCharacter => {
             eprintln!("Parse input error: {error:?}");
             CODE_READ_ERROR

src/cpon.rs

@@ -572,7 +572,7 @@ mod test
     use std::collections::BTreeMap;
     use chrono::{Duration, FixedOffset, LocalResult, NaiveDate, NaiveDateTime, NaiveTime, TimeZone, Utc};
     use crate::cpon::CponReader;
-    use crate::reader::Reader;
+    use crate::reader::{ReadErrorReason, Reader};
     use crate::rpcvalue::Map;
     #[test]
     fn test_read() {
@@ -604,7 +604,7 @@ mod test
         test_cpon_round_trip("1000000.", Decimal::new(1_000_000, 0));
         test_cpon_round_trip("50.03138741402532", Decimal::new(5_003_138_741_402_532, -14));
         // We do not support such high precision.
-        assert!(RpcValue::from_cpon("36.028797018963968").is_err());
+        assert!(RpcValue::from_cpon("36.028797018963968").is_err_and(|err| matches!(err.reason, ReadErrorReason::NumericValueOverflow)));
         assert_eq!(RpcValue::from_cpon(r#""foo""#).unwrap().as_str(), "foo");
         assert_eq!(RpcValue::from_cpon(r#""ěščřžýáí""#).unwrap().as_str(), "ěščřžýáí");
         assert_eq!(RpcValue::from_cpon("b\"foo\tbar\nbaz\"").unwrap().as_blob(), b"foo\tbar\nbaz");
@@ -706,8 +706,8 @@ mod test
         assert_eq!(RpcValue::from_cpon("-0x8000000000000000").unwrap().as_int(), i64::MIN);
         assert_eq!(RpcValue::from_cpon("-0x8000000000000001").unwrap().as_int(), i64::MIN);
 
-        assert!(RpcValue::from_cpon("1.23456789012345678901234567890123456789012345678901234567890").is_err());
-        assert!(RpcValue::from_cpon("12345678901234567890123456789012345678901234567890123456.7890").is_err());
-        assert!(RpcValue::from_cpon("123456789012345678901234567890123456789012345678901234567890.").is_err());
+        assert!(RpcValue::from_cpon("1.23456789012345678901234567890123456789012345678901234567890").is_err_and(|err| matches!(err.reason, ReadErrorReason::NumericValueOverflow)));
+        assert!(RpcValue::from_cpon("12345678901234567890123456789012345678901234567890123456.7890").is_err_and(|err| matches!(err.reason, ReadErrorReason::NumericValueOverflow)));
+        assert!(RpcValue::from_cpon("123456789012345678901234567890123456789012345678901234567890.").is_err_and(|err| matches!(err.reason, ReadErrorReason::NumericValueOverflow)));
     }
 }

src/json.rs

@@ -415,6 +415,7 @@ impl<R> Reader for JsonReader<'_, R>
 mod test
 {
     use crate::Map;
+    use crate::reader::ReadErrorReason;
     use chrono::{Duration, FixedOffset, LocalResult};
     use crate::json::{TAG_META, TAG_TYPE};
     use crate::{Decimal, IMap, RpcValue};
@@ -567,8 +568,8 @@ mod test
         assert_eq!(RpcValue::from_json("-0x8000000000000000").unwrap().as_int(), i64::MIN);
         assert_eq!(RpcValue::from_json("-0x8000000000000001").unwrap().as_int(), i64::MIN);
 
-        assert!(RpcValue::from_json("1.23456789012345678901234567890123456789012345678901234567890").is_err());
-        assert!(RpcValue::from_json("12345678901234567890123456789012345678901234567890123456.7890").is_err());
-        assert!(RpcValue::from_json("123456789012345678901234567890123456789012345678901234567890.").is_err());
+        assert!(RpcValue::from_json("1.23456789012345678901234567890123456789012345678901234567890").is_err_and(|err| matches!(err.reason, ReadErrorReason::NumericValueOverflow)));
+        assert!(RpcValue::from_json("12345678901234567890123456789012345678901234567890123456.7890").is_err_and(|err| matches!(err.reason, ReadErrorReason::NumericValueOverflow)));
+        assert!(RpcValue::from_json("123456789012345678901234567890123456789012345678901234567890.").is_err_and(|err| matches!(err.reason, ReadErrorReason::NumericValueOverflow)));
     }
 }

src/reader.rs

@@ -6,7 +6,7 @@ use crate::rpcvalue::Value;
 pub enum ReadErrorReason {
     UnexpectedEndOfStream,
     InvalidCharacter,
-    NotEnoughPrecision,
+    NumericValueOverflow,
 }
 #[derive(Debug)]
 pub struct ReadError {

src/textrdwr.rs

@@ -233,7 +233,7 @@ pub trait TextReader : Reader {
                     let ReadInt { value, digit_cnt, is_overflow, .. } = self.read_int(mantissa, true)?;
                     decimal_overflow = decimal_overflow || is_overflow;
                     mantissa = value;
-                    if mantissa >= 36_028_797_018_963_968 {
+                    if mantissa >= 0x80_0000_0000_0000 {
                         decimal_overflow = true;
                     }
                     dec_cnt = i64::from(digit_cnt);
@@ -260,7 +260,7 @@ pub trait TextReader : Reader {
         let mantissa = if is_negative { -mantissa } else { mantissa };
         if is_decimal {
             if decimal_overflow {
-                return Err(self.make_error("Not enough precision to read the Decimal", ReadErrorReason::InvalidCharacter))
+                return Err(self.make_error("Not enough precision to read the Decimal", ReadErrorReason::NumericValueOverflow))
             }
             #[expect(clippy::cast_possible_truncation, reason = "We hope that the new exponent is not big enough to truncate")]
             return Ok(Value::from(Decimal::new(mantissa, (exponent - dec_cnt) as i8)))