Akihiro Sagawa : ntdll: Return correct time zone names for Asia/ Tokyo and Asia/Yakutsk.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 35d93e02d1a26586f4688d36895668cdeaa04feb
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=35d93e02d1a26586f4688d36895668cdeaa04feb

Author: Akihiro Sagawa <sagawa.aki at gmail.com>
Date:   Sun Dec  3 23:26:05 2017 +0900

ntdll: Return correct time zone names for Asia/Tokyo and Asia/Yakutsk.

Without this change, for Japan, Wine returns "Korea Standard Time",
not "Tokyo Standard Time" as seen in Bug 42719.

Actually, this is a regression by d666143f880f9e19849f8f2b520dc059a11750d1.
The new code relies on offsets from UTC and DST change timings.  However,
Northeast Asia regions don't use daylight saving time.  Thus, Wine can't
distinguish between these regions.

Signed-off-by: Akihiro Sagawa <sagawa.aki at gmail.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 dlls/ntdll/time.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 53 insertions(+), 5 deletions(-)

diff --git a/dlls/ntdll/time.c b/dlls/ntdll/time.c
index 12dbdc3..e2cd770 100644
--- a/dlls/ntdll/time.c
+++ b/dlls/ntdll/time.c
@@ -53,6 +53,12 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(ntdll);
 
+#define SHORT_TZ_NAME_MAX 8
+struct tz_name_map {
+    WCHAR key_name[128];
+    char short_name[SHORT_TZ_NAME_MAX];
+};
+
 static int init_tz_info(RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi);
 
 static RTL_CRITICAL_SECTION TIME_tz_section;
@@ -571,6 +577,42 @@ static BOOL match_tz_info(const RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi, const RT
     return FALSE;
 }
 
+static int compare_tz_key(const void *a, const void *b)
+{
+    const struct tz_name_map *map_a, *map_b;
+    map_a = (const struct tz_name_map *)a;
+    map_b = (const struct tz_name_map *)b;
+    return strcmpW(map_a->key_name, map_b->key_name);
+}
+
+static BOOL match_tz_name(const char* tz_name,
+                          const RTL_DYNAMIC_TIME_ZONE_INFORMATION *reg_tzi)
+{
+    static const struct tz_name_map mapping[] = {
+        { {'K','o','r','e','a',' ','S','t','a','n','d','a','r','d',' ','T','i',
+           'm','e',0 },
+          "KST" },
+        { {'T','o','k','y','o',' ','S','t','a','n','d','a','r','d',' ','T','i',
+           'm','e',0 },
+          "JST" },
+        { {'Y','a','k','u','t','s','k',' ','S','t','a','n','d','a','r','d',' ',
+           'T','i','m','e',0 },
+          "+09" }, /* YAKST was used until tzdata 2016f */
+    };
+    struct tz_name_map *match, key;
+
+    if (reg_tzi->DaylightDate.wMonth)
+        return TRUE;
+
+    strcpyW(key.key_name, reg_tzi->TimeZoneKeyName);
+    match = bsearch(&key, mapping, sizeof(mapping)/sizeof(mapping[0]),
+                    sizeof(mapping[0]), compare_tz_key);
+    if (!match)
+        return TRUE;
+
+    return !strcmp(match->short_name, tz_name);
+}
+
 static BOOL reg_query_value(HKEY hkey, LPCWSTR name, DWORD type, void *data, DWORD count)
 {
     UNICODE_STRING nameW;
@@ -592,7 +634,7 @@ static BOOL reg_query_value(HKEY hkey, LPCWSTR name, DWORD type, void *data, DWO
     return TRUE;
 }
 
-static void find_reg_tz_info(RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi, int year)
+static void find_reg_tz_info(RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi, const char* tz_name, int year)
 {
     static const WCHAR Time_ZonesW[] = { 'M','a','c','h','i','n','e','\\',
         'S','o','f','t','w','a','r','e','\\',
@@ -714,7 +756,8 @@ static void find_reg_tz_info(RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi, int year)
 
         NtClose(hSubkey);
 
-        if (match_tz_info(tzi, &reg_tzi))
+        if (match_tz_info(tzi, &reg_tzi)
+            && match_tz_name(tz_name, &reg_tzi))
         {
             *tzi = reg_tzi;
             NtClose(hkey);
@@ -729,8 +772,8 @@ static void find_reg_tz_info(RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi, int year)
     NtClose(hkey);
 
     FIXME("Can't find matching timezone information in the registry for "
-          "bias %d, std (d/m/y): %u/%02u/%04u, dlt (d/m/y): %u/%02u/%04u\n",
-          tzi->Bias,
+          "%s, bias %d, std (d/m/y): %u/%02u/%04u, dlt (d/m/y): %u/%02u/%04u\n",
+          tz_name, tzi->Bias,
           tzi->StandardDate.wDay, tzi->StandardDate.wMonth, tzi->StandardDate.wYear,
           tzi->DaylightDate.wDay, tzi->DaylightDate.wMonth, tzi->DaylightDate.wYear);
 }
@@ -763,6 +806,7 @@ static int init_tz_info(RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi)
     static RTL_DYNAMIC_TIME_ZONE_INFORMATION cached_tzi;
     static int current_year = -1, current_bias = 65535;
     struct tm *tm;
+    char tz_name[SHORT_TZ_NAME_MAX];
     time_t year_start, year_end, tmp, dlt = 0, std = 0;
     int is_dst, current_is_dst, bias;
 
@@ -782,6 +826,10 @@ static int init_tz_info(RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi)
     }
 
     memset(tzi, 0, sizeof(*tzi));
+    if (!strftime(tz_name, sizeof(tz_name), "%Z", tm)) {
+        /* not enough room or another error */
+        tz_name[0] = '\0';
+    }
 
     TRACE("tz data will be valid through year %d, bias %d\n", tm->tm_year + 1900, bias);
     current_year = tm->tm_year;
@@ -864,7 +912,7 @@ static int init_tz_info(RTL_DYNAMIC_TIME_ZONE_INFORMATION *tzi)
             tzi->StandardBias);
     }
 
-    find_reg_tz_info(tzi, current_year + 1900);
+    find_reg_tz_info(tzi, tz_name, current_year + 1900);
     cached_tzi = *tzi;
 
     RtlLeaveCriticalSection( &TIME_tz_section );