[PATCH 0/1] MR4851: kernelbase: Add naive SystemTimeToTzSpecificLocalTimeEx implementation

[Russell Greene (＠russelltg)]

The cast there seems safe from looking at the struct definitions, and is also used elsewhere in the codebase (dlls/kernelbase/locale.c:5682).

It's obviously not a full implementation, but works well enough for my usecase and maybe others as well.

[PATCH 1/1] kernelbase: Add naive SystemTimeToTzSpecificLocalTimeEx implementation

[Russell Greene]

From: Russell Greene

---
 dlls/kernel32/kernel32.spec     |  2 +-
 dlls/kernelbase/kernelbase.spec |  2 +-
 dlls/kernelbase/locale.c        | 12 ++++++++++++
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/dlls/kernel32/kernel32.spec b/dlls/kernel32/kernel32.spec
index bb9c8fbfe0e..be9a0f1c490 100644
--- a/dlls/kernel32/kernel32.spec
+++ b/dlls/kernel32/kernel32.spec
@@ -1528,7 +1528,7 @@
 @ stdcall -import SwitchToThread()
 @ stdcall -import SystemTimeToFileTime(ptr ptr)
 @ stdcall -import SystemTimeToTzSpecificLocalTime (ptr ptr ptr)
-# @ stub SystemTimeToTzSpecificLocalTimeEx
+@ stdcall -import SystemTimeToTzSpecificLocalTimeEx (ptr ptr ptr)
 @ stdcall TerminateJobObject(long long)
 @ stdcall -import TerminateProcess(long long)
 @ stdcall -import TerminateThread(long long)
diff --git a/dlls/kernelbase/kernelbase.spec b/dlls/kernelbase/kernelbase.spec
index ffb153a46ee..2c38bc5c348 100644
--- a/dlls/kernelbase/kernelbase.spec
+++ b/dlls/kernelbase/kernelbase.spec
@@ -1634,7 +1634,7 @@
 @ stdcall SwitchToThread()
 @ stdcall SystemTimeToFileTime(ptr ptr)
 @ stdcall SystemTimeToTzSpecificLocalTime(ptr ptr ptr)
-@ stub SystemTimeToTzSpecificLocalTimeEx
+@ stdcall SystemTimeToTzSpecificLocalTimeEx(ptr ptr ptr)
 @ stdcall TerminateProcess(long long)
 # @ stub TerminateProcessOnMemoryExhaustion
 @ stdcall TerminateThread(long long)
diff --git a/dlls/kernelbase/locale.c b/dlls/kernelbase/locale.c
index 44af29f163d..c6c46c3a629 100644
--- a/dlls/kernelbase/locale.c
+++ b/dlls/kernelbase/locale.c
@@ -7084,6 +7084,18 @@ BOOL WINAPI DECLSPEC_HOTPATCH SystemTimeToTzSpecificLocalTime( const TIME_ZONE_I
 }

+/***********************************************************************
+ *	SystemTimeToTzSpecificLocalTimeEx   (kernelbase.@)
+ */
+BOOL WINAPI DECLSPEC_HOTPATCH SystemTimeToTzSpecificLocalTimeEx( const DYNAMIC_TIME_ZONE_INFORMATION *info,
+                                                                 const SYSTEMTIME *system,
+                                                                 SYSTEMTIME *local )
+{
+    FIXME( "just runs SystemTimeToTzSpecificLocalTime\n" );
+    return SystemTimeToTzSpecificLocalTime( (const TIME_ZONE_INFORMATION *)info, system, local );
+}
+
+
 /***********************************************************************
  *	TzSpecificLocalTimeToSystemTime   (kernelbase.@)
  */

[Nikolay Sivov (＠nsivov)]

I imagine this will produce incorrect results when you actually have dynamic DST data, and it's not that rare. Could you name an application that needs this?

[Russell Greene (＠russelltg)]

I added this for a proprietary mapping app. Yeah, it's not a correct implementation, but it allowed the app to not crash and actually to run pretty decently.

I can probably find some time to look into a proper implementation, but it was certainly enough for me.