From 10c941c1087f3f4e24f505391fe30082b1020c6f Mon Sep 17 00:00:00 2001
From: Arun Sharma <arun@sharma-home.net>
Date: Tue, 7 Jul 2026 12:49:20 -0700
Subject: [PATCH] fix: allow leading zeros in CAST(string AS INT64)

The tryIntegerCast function had an explicit check rejecting any
non-negative integer string starting with '0' (beyond just 0).
This caused CAST('000012' AS INT64) to fail with a conversion
exception, even though leading zeros are valid in integer
representations.

Removed the leading-zero restriction. The integerCastLoop digit
parser handles leading zeros naturally.
---
 .../cast/functions/cast_string_non_nested_functions.h         | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/src/include/function/cast/functions/cast_string_non_nested_functions.h b/src/include/function/cast/functions/cast_string_non_nested_functions.h
index 550e845f5f..560406f6d6 100644
--- a/src/include/function/cast/functions/cast_string_non_nested_functions.h
+++ b/src/include/function/cast/functions/cast_string_non_nested_functions.h
@@ -233,10 +233,6 @@ inline bool tryIntegerCast(const char* input, uint64_t& len, IntegerCastData<T>&
         return integerCastLoop<T, true>(input, len, result);
     }
 
-    // not allow leading 0
-    if (len > 1 && *input == '0') {
-        return false;
-    }
     return integerCastLoop<T, false>(input, len, result);
 }