commit 02db5b95e6e1968f73cd6d118650d8547c264ac2
author Siva Annamalai <asiva@google.com> Thu Nov 16 18:24:38 2023 +0000
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Nov 16 18:24:38 2023 +0000
tree 89831c76edbe04122113da014157e6aa945d0352
parent 18b5f25052fcefa85661e989750e14bd5e9c48e9

Revert "Call tzset() before localtime_r()."

This reverts commit 6027bcb1e2b059b6f8b64b0927831cff83e238c7.

Reason for revert: We are seeing TSAN failures in the bot runs

Original change's description:
> Call tzset() before localtime_r().
>
> POSIX and glibc do not guarantee that tzset() is called by localtime_r(). tzset sets the timezone name, UTC offset and whether or not it is daylight savings time.
>
> Android <= 7.1.1 did *not* call tzset() in localtime_r(), which means that users will see their timezone as "GMT".
>
> macOS/iOS seem to guarantee that tzset() is called by localtime_r() but the wording is vague:
>
>   localtime_r() and gmtime_r() functions provide the same functionality
>   as localtime() and gmtime()...
>
> N.B.: localtime() is guaranteed to call tzset().
>
> tzset() must be called before each localtime_r() to catch the case where the user changes the timezone while the application is running.
>
> Bug:https://github.com/dart-lang/sdk/issues/53276
> Change-Id: I0503a0a109aa6c281c9a3aefe8ba0b54841a42a7
> Tested: manually tested on Android 7.1.1
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/336240
> Reviewed-by: Siva Annamalai <asiva@google.com>
> Commit-Queue: Brian Quinlan <bquinlan@google.com>

Bug: https://github.com/dart-lang/sdk/issues/53276
Change-Id: I4bbadf2b69eeac583b7da605c0686bcc6f72081f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/336721
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Siva Annamalai <asiva@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>

runtime/vm/os_android.cc

diff --git a/runtime/vm/os_android.cc b/runtime/vm/os_android.cc
index 2723219..e7b502e 100644
--- a/runtime/vm/os_android.cc
+++ b/runtime/vm/os_android.cc
@@ -101,7 +101,6 @@
 static bool LocalTime(int64_t seconds_since_epoch, tm* tm_result) {
   time_t seconds = static_cast<time_t>(seconds_since_epoch);
   if (seconds != seconds_since_epoch) return false;
-  tzset();  // Not guaranteed by POSIX to be called by `localtime_r`.
   struct tm* error_code = localtime_r(&seconds, tm_result);
   return error_code != nullptr;
 }

runtime/vm/os_linux.cc

diff --git a/runtime/vm/os_linux.cc b/runtime/vm/os_linux.cc
index 002221d..8d98395 100644
--- a/runtime/vm/os_linux.cc
+++ b/runtime/vm/os_linux.cc
@@ -418,7 +418,6 @@
 static bool LocalTime(int64_t seconds_since_epoch, tm* tm_result) {
   time_t seconds = static_cast<time_t>(seconds_since_epoch);
   if (seconds != seconds_since_epoch) return false;
-  tzset();  // Not guaranteed by POSIX to be called by `localtime_r`.
   struct tm* error_code = localtime_r(&seconds, tm_result);
   return error_code != nullptr;
 }

runtime/vm/os_macos.cc

diff --git a/runtime/vm/os_macos.cc b/runtime/vm/os_macos.cc
index 17b4f02..d942096 100644
--- a/runtime/vm/os_macos.cc
+++ b/runtime/vm/os_macos.cc
@@ -36,7 +36,6 @@
 static bool LocalTime(int64_t seconds_since_epoch, tm* tm_result) {
   time_t seconds = static_cast<time_t>(seconds_since_epoch);
   if (seconds != seconds_since_epoch) return false;
-  tzset();  // Not guaranteed by POSIX to be called by `localtime_r`.
   struct tm* error_code = localtime_r(&seconds, tm_result);
   return error_code != nullptr;
 }