From 50a1267b7d028f18df39523fd90399f0751180a4 Mon Sep 17 00:00:00 2001
From: Ruslan Mustakov <r.mustakov@gmail.com>
Date: Wed, 30 Nov 2016 20:28:17 +0700
Subject: [PATCH 1/2] Fix TimeInfo to Time conversion. Fixes #5065.

---
 lib/pure/times.nim | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/lib/pure/times.nim b/lib/pure/times.nim
index 1767a37be3..e5b4f383f3 100644
--- a/lib/pure/times.nim
+++ b/lib/pure/times.nim
@@ -436,6 +436,13 @@ when not defined(JS):
     TimeInfoPtr = ptr StructTM
     Clock {.importc: "clock_t".} = distinct int
 
+  when defined(windows):
+    proc timegm(t: StructTM): Time {.
+      importc: "_mkgmtime", header: "<time.h>", tags: [].}
+  else:
+    proc timegm(t: StructTM): Time {.
+      importc: "timegm", header: "<time.h>", tags: [].}
+
   proc localtime(timer: ptr Time): TimeInfoPtr {.
     importc: "localtime", header: "<time.h>", tags: [].}
   proc gmtime(timer: ptr Time): TimeInfoPtr {.
@@ -516,19 +523,17 @@ when not defined(JS):
 
   proc timeInfoToTime(timeInfo: TimeInfo): Time =
     var cTimeInfo = timeInfo # for C++ we have to make a copy,
-    # because the header of mktime is broken in my version of libc
-    result = mktime(timeInfoToTM(cTimeInfo))
-    # mktime is defined to interpret the input as local time. As timeInfoToTM
-    # does ignore the timezone, we need to adjust this here.
-    result = Time(TimeImpl(result) - getTimezone() + timeInfo.timezone)
+    # because the header of timegm is broken in my version of libc
+    result = timegm(timeInfoToTM(cTimeInfo))
+    # As timeInfoToTM does ignore the timezone, we need to adjust this here.
+    result = Time(TimeImpl(result) + timeInfo.timezone)
 
   proc toTime(timeInfo: TimeInfo): Time =
     var cTimeInfo = timeInfo # for C++ we have to make a copy,
-    # because the header of mktime is broken in my version of libc
-    result = mktime(timeInfoToTM(cTimeInfo))
-    # mktime is defined to interpret the input as local time. As timeInfoToTM
-    # does ignore the timezone, we need to adjust this here.
-    result = Time(TimeImpl(result) - getTimezone() + timeInfo.timezone)
+    # because the header of timegm is broken in my version of libc
+    result = timegm(timeInfoToTM(cTimeInfo))
+    # As timeInfoToTM does ignore the timezone, we need to adjust this here.
+    result = Time(TimeImpl(result) + timeInfo.timezone)
 
   const
     epochDiff = 116444736000000000'i64

From dc8ee72eb6069c181621a3dc4ad97f8cced9db4b Mon Sep 17 00:00:00 2001
From: Dmitry Polienko <dmitry@eldis.ru>
Date: Tue, 6 Dec 2016 14:16:00 +0700
Subject: [PATCH 2/2] Revert @endragor's fix for Windows

_mkgmtime is not supported by mingw because of the older msvcrt
versions. Fortunately, mktime implementation in Windows is just broken
enough to make the initial implementation work...

As far as I can tell, this works with both *nix-like platforms
and Win, and fixes #4690
---
 lib/pure/times.nim | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/lib/pure/times.nim b/lib/pure/times.nim
index e5b4f383f3..cf4e7dde64 100644
--- a/lib/pure/times.nim
+++ b/lib/pure/times.nim
@@ -436,10 +436,8 @@ when not defined(JS):
     TimeInfoPtr = ptr StructTM
     Clock {.importc: "clock_t".} = distinct int
 
-  when defined(windows):
-    proc timegm(t: StructTM): Time {.
-      importc: "_mkgmtime", header: "<time.h>", tags: [].}
-  else:
+  when not defined(windows):
+    # This is not ANSI C, but common enough
     proc timegm(t: StructTM): Time {.
       importc: "timegm", header: "<time.h>", tags: [].}
 
@@ -522,18 +520,22 @@ when not defined(JS):
     # the conversion is not expensive
 
   proc timeInfoToTime(timeInfo: TimeInfo): Time =
-    var cTimeInfo = timeInfo # for C++ we have to make a copy,
-    # because the header of timegm is broken in my version of libc
-    result = timegm(timeInfoToTM(cTimeInfo))
-    # As timeInfoToTM does ignore the timezone, we need to adjust this here.
-    result = Time(TimeImpl(result) + timeInfo.timezone)
+    toTime(timeInfo)
 
   proc toTime(timeInfo: TimeInfo): Time =
-    var cTimeInfo = timeInfo # for C++ we have to make a copy,
-    # because the header of timegm is broken in my version of libc
-    result = timegm(timeInfoToTM(cTimeInfo))
-    # As timeInfoToTM does ignore the timezone, we need to adjust this here.
-    result = Time(TimeImpl(result) + timeInfo.timezone)
+    var cTimeInfo = timeInfo # for C++ we have to make a copy
+    # because the header of mktime is broken in my version of libc
+
+    when defined(windows):
+      # On Windows `mktime` is broken enough to make this work.
+      result = mktime(timeInfoToTM(cTimeInfo))
+      # mktime is defined to interpret the input as local time. As timeInfoToTM
+      # does ignore the timezone, we need to adjust this here.
+      result = Time(TimeImpl(result) - getTimezone() + timeInfo.timezone)
+    else:
+      result = timegm(timeInfoToTM(cTimeInfo))
+      # As timeInfoToTM does ignore the timezone, we need to adjust this here.
+      result = Time(TimeImpl(result) + timeInfo.timezone)
 
   const
     epochDiff = 116444736000000000'i64