From a655be823b501063325a0580b05437d7bb8a995f Mon Sep 17 00:00:00 2001
From: Owen Clarke <o.clarke@gmail.com>
Date: Mon, 16 Jul 2012 22:45:11 +1000
Subject: [PATCH] Bug #1030

- Added portable implementation of timegm for non GNU/BSD platforms that
  don't have their own implementation
- Removed the use of tm_gmtoff on non GNU/BSD platforms that don't have
  it as part of the tm struct in time.h
- Added CMake tests HAVE_TIMEGM and HAVE_TM_GMTOFF
---
 CMakeLists.txt  |  4 ++++
 ChangeLog       |  2 ++
 cmake.h.in      |  6 ++++++
 src/Nibbler.cpp |  3 +++
 src/util.cpp    | 20 ++++++++++++++++++++
 src/util.h      |  4 ++++
 6 files changed, 39 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5f3893411..bf3957d15 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,6 +2,7 @@ cmake_minimum_required (VERSION 2.8)
 set(CMAKE_LEGACY_CYGWIN_WIN32 0) # Remove when CMake >= 2.8.4 is required
 
 include (CheckFunctionExists)
+include (CheckStructHasMember)
 
 set (HAVE_CMAKE true)
 
@@ -65,6 +66,9 @@ endif (LUA51_FOUND)
 
 check_function_exists (random  HAVE_RANDOM)
 check_function_exists (srandom HAVE_SRANDOM)
+check_function_exists (timegm  HAVE_TIMEGM)
+
+check_struct_has_member ("struct tm" tm_gmtoff time.h HAVE_TM_GMTOFF)
 
 message ("-- Looking for libuuid")
 if (DARWIN)
diff --git a/ChangeLog b/ChangeLog
index 18610baaf..18ff00d46 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -110,6 +110,8 @@ Bugs
    modification (thanks to Christoph Lange).
  + Fixed bug #1028, so that UDA durations are stored in seconds, not in raw form
    (thank to Uli Martens).
+ + Fixed bug #1030, which defines a portable implementation of timegm and removes
+   the use of tm_gmtoff for non GNU/BSD platforms.
 
 ------ old releases ------------------------------
 
diff --git a/cmake.h.in b/cmake.h.in
index cb5088433..a3bb1aca1 100644
--- a/cmake.h.in
+++ b/cmake.h.in
@@ -57,6 +57,12 @@ Override PACKAGE_LANGUAGE, then
 /* Found srandom */
 #cmakedefine HAVE_SRANDOM
 
+/* Found tm_gmtoff */
+#cmakedefine HAVE_TM_GMTOFF
+
+/* Found timegm */
+#cmakedefine HAVE_TIMEGM
+
 /* Found the uuid library */
 #cmakedefine HAVE_UUID
 #cmakedefine HAVE_UUID_UNPARSE_LOWER
diff --git a/src/Nibbler.cpp b/src/Nibbler.cpp
index a6f2e57e1..0a967c46b 100644
--- a/src/Nibbler.cpp
+++ b/src/Nibbler.cpp
@@ -37,6 +37,7 @@
 #ifdef NIBBLER_FEATURE_REGEX
 #include <RX.h>
 #endif
+#include <cmake.h>
 
 static const char*        _uuid_pattern    = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";
 static const unsigned int _uuid_min_length = 9;
@@ -701,7 +702,9 @@ bool Nibbler::getDateISO (time_t& t)
       tms.tm_hour   = hour;
       tms.tm_min    = minute;
       tms.tm_sec    = second;
+#ifdef HAVE_TM_GMTOFF
       tms.tm_gmtoff = 0;
+#endif
 
       t = timegm (&tms);
       return true;
diff --git a/src/util.cpp b/src/util.cpp
index e3024be41..63ab05a74 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -610,3 +610,23 @@ const std::string indentProject (
 
 ////////////////////////////////////////////////////////////////////////////////
 
+////////////////////////////////////////////////////////////////////////////////
+#ifndef HAVE_TIMEGM
+time_t timegm (struct tm *tm)
+{
+  time_t ret;
+  char *tz;
+  tz = getenv ("TZ");
+  setenv ("TZ", "UTC", 1);
+  tzset ();
+  ret = mktime (tm);
+  if (tz)
+    setenv ("TZ", tz, 1);
+  else
+    unsetenv ("TZ");
+  tzset ();
+  return ret;
+}
+#endif
+////////////////////////////////////////////////////////////////////////////////
+
diff --git a/src/util.h b/src/util.h
index 411b76ce2..d5d48831a 100644
--- a/src/util.h
+++ b/src/util.h
@@ -84,5 +84,9 @@ const std::string indentProject (
   const std::string& whitespace = "  ",
   char delimiter = '.');
 
+#ifndef HAVE_TIMEGM
+  time_t timegm (struct tm *tm);
+#endif
+
 #endif
 ////////////////////////////////////////////////////////////////////////////////