From b79d3e0f07495b4a113f1ad95ae08c19664ea5ac Mon Sep 17 00:00:00 2001
From: Michael Sweet <michael.r.sweet@gmail.com>
Date: Sun, 23 Apr 2017 12:49:40 -0400
Subject: [PATCH] Add support for SOURCE_DATE_EPOCH environment variable (Issue
 #193)

---
 CHANGES.md   | 2 ++
 doc/mxml.man | 2 +-
 mxmldoc.c    | 9 ++++++++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index d82b4d1..9d6c3de 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,8 @@
   (Issue #184)
 - The configure script now properly supports cross-compilation (Issue #188)
 - The mxmldoc utility now supports generation of EPUB files (Issue #189)
+- The mxmldoc utility now supports the `SOURCE_DATE_EPOCH` environment
+  variable for reproducible builds (Issue #193)
 - The mxmldoc utility now supports Markdown (Issue #194)
 
 
diff --git a/doc/mxml.man b/doc/mxml.man
index d523307..6bcd2c0 100644
--- a/doc/mxml.man
+++ b/doc/mxml.man
@@ -1,4 +1,4 @@
-.TH mxml 3 "Mini-XML API" "04/21/17" "Mini-XML API"
+.TH mxml 3 "Mini-XML API" "04/23/17" "Mini-XML API"
 .SH NAME
 mxml \- Mini-XML API
 .SH INCLUDE FILE
diff --git a/mxmldoc.c b/mxmldoc.c
index 7f475ef..4abe707 100644
--- a/mxmldoc.c
+++ b/mxmldoc.c
@@ -5604,6 +5604,7 @@ write_man(const char  *man_name,	/* I - Name of manpage */
 		*parent;		/* Parent class */
   int		inscope;		/* Variable/method scope */
   char		prefix;			/* Prefix character */
+  const char	*source_date_epoch;	/* SOURCE_DATE_EPOCH environment variable */
   time_t	curtime;		/* Current time */
   struct tm	*curdate;		/* Current date */
   char		buffer[1024];		/* String buffer */
@@ -5617,9 +5618,15 @@ write_man(const char  *man_name,	/* I - Name of manpage */
 
  /*
   * Standard man page...
+  *
+  * Get the current date, using the SOURCE_DATE_EPOCH environment variable, if
+  * present, for the number of seconds since the epoch - this enables
+  * reproducible builds (Issue #193).
   */
 
-  curtime = time(NULL);
+  if ((source_date_epoch = getenv("SOURCE_DATE_EPOCH")) == NULL || (curtime = (time_t)strtol(source_date_epoch, NULL, 10)) <= 0)
+    curtime = time(NULL);
+
   curdate = localtime(&curtime);
   strftime(buffer, sizeof(buffer), "%x", curdate);