diff --git a/core/src/execution/datafusion/expressions/cast.rs b/core/src/execution/datafusion/expressions/cast.rs
index a7721f339..f68732fb1 100644
--- a/core/src/execution/datafusion/expressions/cast.rs
+++ b/core/src/execution/datafusion/expressions/cast.rs
@@ -1010,12 +1010,6 @@ fn cast_string_to_int_with_range_check(
     }
 }
 
-#[derive(PartialEq)]
-enum State {
-    ParseSignAndDigits,
-    ParseFractionalDigits,
-}
-
 /// Equivalent to
 /// - org.apache.spark.unsafe.types.UTF8String.toInt(IntWrapper intWrapper, boolean allowDecimal)
 /// - org.apache.spark.unsafe.types.UTF8String.toLong(LongWrapper longWrapper, boolean allowDecimal)
@@ -1036,15 +1030,13 @@ fn do_cast_string_to_int<
     let mut negative = false;
     let radix = T::from(10);
     let stop_value = min_value / radix;
-    let mut state = State::ParseSignAndDigits;
-    let mut parsed_sign = false;
+    let mut parse_sign_and_digits = true;
 
     for (i, ch) in trimmed_str.char_indices() {
-        if state == State::ParseSignAndDigits {
-            if !parsed_sign {
+        if parse_sign_and_digits {
+            if i == 0 {
                 negative = ch == '-';
                 let positive = ch == '+';
-                parsed_sign = true;
                 if negative || positive {
                     if i + 1 == len {
                         // input string is just "+" or "-"
@@ -1058,7 +1050,7 @@ fn do_cast_string_to_int<
             if ch == '.' {
                 if eval_mode == EvalMode::Legacy {
                     // truncate decimal in legacy mode
-                    state = State::ParseFractionalDigits;
+                    parse_sign_and_digits = false;
                     continue;
                 } else {
                     return none_or_err(eval_mode, type_name, str);
@@ -1090,9 +1082,8 @@ fn do_cast_string_to_int<
                     return none_or_err(eval_mode, type_name, str);
                 }
             }
-        }
-
-        if state == State::ParseFractionalDigits {
+        } else {
+            // make sure fractional digits are valid digits but ignore them
             if !ch.is_ascii_digit() {
                 return none_or_err(eval_mode, type_name, str);
             }