[LANG-1730] DateUtils.parseDateWithLeniency() doesn't accept "GMT" as "zzz" timezone on Android

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.14.0
• Component/s: lang.time.*

Environment

Not working: Android 14 (API 34) phone and emulator, Android 12 (API 31) emulator

Working: Arch Linux OpenJDK 11

Language

Java

• Assignee: Unassigned
• Reporter: Hai Zhang
• Created: 02/Mar/24 23:46
• Updated: 04/Mar/24 03:10

Description

Commons Lang3 3.14.0 DateUtils, i.e. FastDateParser under the hood, doesn't accept "GMT" as a valid timezone for "zzz" on Android 14, but does accept it on desktop OpenJDK 11.

For example, the string "Mon, 01 May 2023 08:52:19 GMT" can't be parsed with pattern "EEE, dd MMM yyyy HH:mm:ss zzz" on Android.

The same issue was reported at https://github.com/bitfireAT/dav4jvm/issues/22 , but I found that it's also not working on Android 12 emulator, so I believe the actual cause is Commons Lang3 using FastDateParser v.s. previously using SimpleDateFormat, instead of upgraded Android platform version.

I debugged this a little bit and found that the generated regex in FastDateParser.TimeZoneStrategy doesn't contain "|gmt|" on Android 14, but does contain "|gmt|" on desktop. I suspect maybe Android has some different timezone info. I also saw the intentional skip for `TimeZones.GMT_ID` in FastDateParser code, which makes me wonder how it got the "|gmt|" on desktop.

Here are the different generated regexes I saw, with unrelated timezones replaced with "...":

```
((?iu)[+-]\d

{4}|GMT[+-]\d{1,2}:\d{2}|yukon time|...|gulf standard time|greenwich mean time|gmt-12:00|gmt-11:00|gmt-10:00|gmt-09:30|gmt-09:00|gmt-08:00|gmt-07:00|gmt-06:00|gmt-05:00|gmt-04:00|gmt-03:30|gmt-03:00|gmt-02:30|gmt-02:00|gmt-01:00|gmt+14:00|gmt+13:45|gmt+13:00|gmt+12:45|gmt+12:00|gmt+11:00|gmt+10:30|gmt+10:00|gmt+09:30|gmt+09:00|gmt+08:45|gmt+08:00|gmt+07:00|gmt+06:30|gmt+06:00|gmt+05:45|gmt+05:30|gmt+05:00|gmt+04:30|gmt+04:00|gmt+03:30|gmt+03:00|gmt+02:00|gmt+01:00|gmt+00:00|gilbert islands time|...|acre standard time)
```

```
((?iu)[+-]\d{4}

|GMT[+-]\d

{1,2}

:\d

{2}

|yekt|...|gulf daylight time|gt|gst|greenwich mean time|gmt-12:00|gmt-11:00|gmt-10:00|gmt-09:00|gmt-08:00|gmt-07:00|gmt-06:00|gmt-05:00|gmt-04:00|gmt-03:00|gmt-02:00|gmt-01:00|gmt+14:00|gmt+13:00|gmt+12:00|gmt+11:00|gmt+10:00|gmt+09:00|gmt+08:00|gmt+07:00|gmt+06:00|gmt+05:00|gmt+04:00|gmt+03:00|gmt+02:00|gmt+01:00|gmt|gilt|....|acre standard time|acdt)
```