From bbdb0ab6a8a576fb9da0f57908d9e725c4925849 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herm=C3=A8s=20B=C3=A9lusca-Ma=C3=AFto?=
 <hermes.belusca-maito@reactos.org>
Date: Sun, 19 Apr 2020 18:50:00 +0200
Subject: [PATCH] [TZLIB] QueryTimeZoneData(): Don't fail if the optional
 values "Display", "Std", "Dlt" are missing (or too long to be captured).
 However fail if the timezone information is missing.

---
 sdk/lib/tzlib/tzlib.c | 52 +++++++++++++++++++++++--------------------
 1 file changed, 28 insertions(+), 24 deletions(-)

diff --git a/sdk/lib/tzlib/tzlib.c b/sdk/lib/tzlib/tzlib.c
index 93c33a3fb3a..1dc0cbe7f76 100644
--- a/sdk/lib/tzlib/tzlib.c
+++ b/sdk/lib/tzlib/tzlib.c
@@ -152,6 +152,30 @@ QueryTimeZoneData(
     LONG lError;
     DWORD dwValueSize;
 
+    if (Index)
+    {
+        dwValueSize = sizeof(*Index);
+        lError = RegQueryValueExW(hZoneKey,
+                                  L"Index",
+                                  NULL,
+                                  NULL,
+                                  (LPBYTE)Index,
+                                  &dwValueSize);
+        if (lError != ERROR_SUCCESS)
+            *Index = 0;
+    }
+
+    /* The time zone information structure is mandatory for a valid time zone */
+    dwValueSize = sizeof(*TimeZoneInfo);
+    lError = RegQueryValueExW(hZoneKey,
+                              L"TZI",
+                              NULL,
+                              NULL,
+                              (LPBYTE)TimeZoneInfo,
+                              &dwValueSize);
+    if (lError != ERROR_SUCCESS)
+        return lError;
+
     if (Description && DescriptionSize && *DescriptionSize > 0)
     {
         lError = RegQueryValueExW(hZoneKey,
@@ -161,7 +185,7 @@ QueryTimeZoneData(
                                   (LPBYTE)Description,
                                   DescriptionSize);
         if (lError != ERROR_SUCCESS)
-            return lError;
+            *Description = 0;
     }
 
     if (StandardName && StandardNameSize && *StandardNameSize > 0)
@@ -173,7 +197,7 @@ QueryTimeZoneData(
                                   (LPBYTE)StandardName,
                                   StandardNameSize);
         if (lError != ERROR_SUCCESS)
-            return lError;
+            *StandardName = 0;
     }
 
     if (DaylightName && DaylightNameSize && *DaylightNameSize > 0)
@@ -185,30 +209,10 @@ QueryTimeZoneData(
                                   (LPBYTE)DaylightName,
                                   DaylightNameSize);
         if (lError != ERROR_SUCCESS)
-            return lError;
+            *DaylightName = 0;
     }
 
-    if (Index)
-    {
-        dwValueSize = sizeof(*Index);
-        lError = RegQueryValueExW(hZoneKey,
-                                  L"Index",
-                                  NULL,
-                                  NULL,
-                                  (LPBYTE)Index,
-                                  &dwValueSize);
-        if (lError != ERROR_SUCCESS)
-            return lError;
-    }
-
-    dwValueSize = sizeof(*TimeZoneInfo);
-    lError = RegQueryValueExW(hZoneKey,
-                              L"TZI",
-                              NULL,
-                              NULL,
-                              (LPBYTE)TimeZoneInfo,
-                              &dwValueSize);
-    return lError;
+    return ERROR_SUCCESS;
 }
 
 //