[C++][Gandiva] castTIMESTAMP_utf8 and castTIME_utf8 should truncate subseconds beyond milliseconds, not reject them #48866
Description
Describe the bug, including details regarding any error messages, version, and platform.
The Gandiva precompiled time casting functions (castTIMESTAMP_utf8 and castTIME_utf8) incorrectly reject timestamp and time string literals with more than 3 subsecond digits (beyond millisecond precision), instead of truncating them as other implementations do.
Current behavior:
castTIMESTAMP_utf8("2025-03-26 11:34:56.123456789")
// Returns: 0 (error)
// Error: "Invalid millis for timestamp value 2025-03-26 11:34:56.123456789"
castTIME_utf8("09:45:30.123456789")
// Returns: 0 (error)
// Error: "Invalid millis for time value 09:45:30.123456789"Expected behavior:
castTIMESTAMP_utf8("2025-03-26 11:34:56.123456789")
// Should return: equivalent to "2025-03-26 11:34:56.123" (truncated to milliseconds)
castTIME_utf8("09:45:30.123456789")
// Should return: equivalent to "09:45:30.123" (truncated to milliseconds)I'm going to open PR with the fix.
Component(s)
Gandiva