Fix the default timezone detection in ICU....

third_party/icu/source/common/putil.c

 /*
 ******************************************************************************
 *
 *   Copyright (C) 1997-2009, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 ******************************************************************************
 *
 *  FILE NAME : putil.c (previously putil.cpp and ptypes.cpp)
 *
@@ skipping 643 matching lines @@
     /* If we went through the whole string, then it might be okay.
     The timezone is sometimes set to "CST-7CDT", "CST6CDT5,J129,J131/19:30",
     "GRNLNDST3GRNLNDDT" or similar, so we cannot use it.
     The rest of the time it could be an Olson ID. George */
     return (UBool)(id[idx] == 0
         || uprv_strcmp(id, "PST8PDT") == 0
         || uprv_strcmp(id, "MST7MDT") == 0
         || uprv_strcmp(id, "CST6CDT") == 0
         || uprv_strcmp(id, "EST5EDT") == 0);
 }
+
+/* On some Unix-like OS, 'posix' subdirectory in
+   /usr/share/zoneinfo replicates the top-level contents. 'right'
+   subdirectory has the same set of files, but individual files
+   are different from those in the top-level directory or 'posix'
+   because 'right' has files for TAI (Int'l Atomic Time) while 'posix'
+   has files for UTC.
+   When the first match for /etc/localtime is in either of them
+   (usually in posix because 'right' has different file contents),
+   or TZ environment variable points to one of them, createTimeZone
+   fails because, say, 'posix/America/New_York' is not an Olson
+   timezone id ('America/New_York' is). So, we have to remove
+   'posix/' and 'right/' at the beginning. */
+static void removeZoneIDPrefix(const char** id) {
+    if (uprv_strncmp(*id, "posix/", 6) == 0
+        || uprv_strncmp(*id, "right/", 6) == 0)
+    {
+        *id += 6;
+    }
+}
 #endif
 
 #if defined(U_TZNAME) && !defined(U_WINDOWS)
 
 #define CONVERT_HOURS_TO_SECONDS(offset) (int32_t)(offset*3600)
 typedef struct OffsetZoneMapping {
     int32_t offsetSeconds;
     int32_t daylightType; /* 1=daylight in June, 2=daylight in December*/
     const char *stdID;
     const char *dstID;
@@ skipping 188 matching lines @@
     char curpath[MAX_PATH_SIZE];
 
     if (dirp == NULL)
         return result;
 
     uprv_memset(curpath, 0, MAX_PATH_SIZE);
     uprv_strcpy(curpath, path);
 
     /* Check each entry in the directory. */
     while((dirEntry = readdir(dirp)) != NULL) {
-        if (uprv_strcmp(dirEntry->d_name, SKIP1) != 0 && uprv_strcmp(dirEntry->d_name, SKIP2) != 0) {
+        const char* dirName = dirEntry->d_name;
+        if (uprv_strcmp(dirName, SKIP1) != 0 && uprv_strcmp(dirName, SKIP2) != 0) {
             /* Create a newpath with the new entry to test each entry in the directory. */
             char newpath[MAX_PATH_SIZE];
             uprv_strcpy(newpath, curpath);
-            uprv_strcat(newpath, dirEntry->d_name);
+            uprv_strcat(newpath, dirName);
 
             if ((subDirp = opendir(newpath)) != NULL) {
                 /* If this new path is a directory, make a recursive call with the newpath. */
                 closedir(subDirp);
                 uprv_strcat(newpath, "/");
                 result = searchForTZFile(newpath, tzInfo);
                 /*
                  Have to get out here. Otherwise, we'd keep looking
                  and return the first match in the top-level directory
                  if there's a match in the top-level. If not, this function
                  would return NULL and set gTimeZoneBufferPtr to NULL in initDefault().
                  It worked without this in most cases because we have a fallback of calling
                  localtime_r to figure out the default timezone.
                 */
                 if (result != NULL)
                     break;
-            } else if (uprv_strcmp(TZFILE_SKIP, dirEntry->d_name) != 0 && uprv_strcmp(TZFILE_SKIP2, dirEntry->d_name) != 0) {
+            } else if (uprv_strcmp(TZFILE_SKIP, dirName) != 0 && uprv_strcmp(TZFILE_SKIP2, dirName) != 0) {
                 if(compareBinaryFiles(TZDEFAULT, newpath, tzInfo)) {
-                    uprv_strcpy(SEARCH_TZFILE_RESULT, newpath + (sizeof(TZZONEINFO) - 1));
+                    const char* zoneid = newpath + (sizeof(TZZONEINFO)) - 1;
+                    removeZoneIDPrefix(&zoneid);
+                    uprv_strcpy(SEARCH_TZFILE_RESULT, zoneid);
                     result = SEARCH_TZFILE_RESULT;
                     /* Get out after the first one found. */
                     break;
                 }
             }
         }
     }
     closedir(dirp);
     return result;
 }
@@ skipping 18 matching lines @@
         return tzid;
     }
 #endif*/
 
 /* This code can be temporarily disabled to test tzname resolution later on. */
 #ifndef DEBUG_TZNAME
     tzid = getenv("TZ");
     if (tzid != NULL && isValidOlsonID(tzid))
     {
         /* This might be a good Olson ID. */
-        if (uprv_strncmp(tzid, "posix/", 6) == 0
-            || uprv_strncmp(tzid, "right/", 6) == 0)
-        {
-            /* Remove the posix/ or right/ prefix. */
-            tzid += 6;
-        }
+        removeZoneIDPrefix(&tzid);
         return tzid;
     }
     /* else U_TZNAME will give a better result. */
 #endif
 
 #if defined(CHECK_LOCALTIME_LINK)
     /* Caller must handle threading issues */
     if (gTimeZoneBufferPtr == NULL) {
         /*
         This is a trick to look at the name of the link to get the Olson ID
@@ skipping 1033 matching lines @@
 }
 
 /*
  * Hey, Emacs, please set the following:
  *
  * Local Variables:
  * indent-tabs-mode: nil
  * End:
  *
  */