From a7e4724a5eac43fd596b24d5e2e9f53c73510b18 Mon Sep 17 00:00:00 2001
From: Andy Green <andy@warmcat.com>
Date: Sun, 1 Aug 2021 08:55:34 +0100
Subject: [PATCH] http: date: use timegm

---
 CMakeLists.txt        | 1 +
 cmake/lws_config.h.in | 1 +
 lib/roles/http/date.c | 9 +++++++++
 3 files changed, 11 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 06df8ffdb..4718a438d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -561,6 +561,7 @@ CHECK_FUNCTION_EXISTS(getgrgid_r LWS_HAVE_GETGRGID_R)
 CHECK_FUNCTION_EXISTS(getgrnam_r LWS_HAVE_GETGRNAM_R)
 CHECK_FUNCTION_EXISTS(getpwuid_r LWS_HAVE_GETPWUID_R)
 CHECK_FUNCTION_EXISTS(getpwnam_r LWS_HAVE_GETPWNAM_R)
+CHECK_FUNCTION_EXISTS(timegm LWS_HAVE_TIMEGM)
 
 if(CMAKE_SYSTEM_NAME MATCHES "Darwin")
 	if(CMAKE_OSX_DEPLOYMENT_TARGET LESS "10.12")
diff --git a/cmake/lws_config.h.in b/cmake/lws_config.h.in
index 118d1cf7c..b64f29e35 100644
--- a/cmake/lws_config.h.in
+++ b/cmake/lws_config.h.in
@@ -99,6 +99,7 @@
 #cmakedefine LWS_HAVE__STAT32I64
 #cmakedefine LWS_HAVE_STDINT_H
 #cmakedefine LWS_HAVE_SYS_CAPABILITY_H
+#cmakedefine LWS_HAVE_TIMEGM
 #cmakedefine LWS_HAVE_TLS_CLIENT_METHOD
 #cmakedefine LWS_HAVE_TLSV1_2_CLIENT_METHOD
 #cmakedefine LWS_HAVE_SUSECONDS_T
diff --git a/lib/roles/http/date.c b/lib/roles/http/date.c
index 0b0012b6d..6ac42ba9c 100644
--- a/lib/roles/http/date.c
+++ b/lib/roles/http/date.c
@@ -139,7 +139,16 @@ lws_http_date_parse_unix(const char *b, size_t len, time_t *t)
 	if (lws_http_date_parse(b, len, &tm))
 		return -1;
 
+#if defined(WIN32)
+	*t = _mkgmtime(&tm);
+#else
+#if defined(LWS_HAVE_TIMEGM)
+	*t = timegm(&tm);
+#else
+	/* this is a poor fallback since it uses localtime zone */
 	*t = mktime(&tm);
+#endif
+#endif
 
 	return (int)*t == -1 ? -1 : 0;
 }