From: Chris Lamb <lamby@debian.org>
Date: Fri, 12 Jul 2019 05:59:50 +0000 (+0200)
Subject: lsg.c: Make the output of lopsubgen reproducible.
X-Git-Tag: v1.0.4~12
X-Git-Url: http://git.tue.mpg.de/?a=commitdiff_plain;h=0a8299dd8da7dba7437550d12bf180d9e10d512b;p=lopsub.git

lsg.c: Make the output of lopsubgen reproducible.

Whilst working on the Reproducible Builds effort [0], we noticed that
liblopsub generates output that is not reproducible. The lopsubgen
utility does not respect SOURCE_DATE_EPOCH [1] and thus packages such
as src:tfortune are rendered unreproducible as they then encode the
build date and time.

This patch makes lopsubgen honour SOURCE_DATE_EPOCH.

[0] https://reproducible-builds.org/
[1] https://reproducible-builds.org/specs/source-date-epoch/

Signed-off-by: Andre Noll <maan@tuebingen.mpg.de>
---

diff --git a/lsg.c b/lsg.c
index 54b7816..83a72da 100644
--- a/lsg.c
+++ b/lsg.c
@@ -610,7 +610,7 @@ static char *get_output_path(const char *suffix, const char *arg,
 static void gen_man(struct lls_parse_result *lpr, const char *cmdline)
 {
 	int i;
-	time_t t;
+	time_t t = 0;
 	struct tm *tmp;
 	FILE *out;
 	char *outpath = get_output_path("man",
@@ -626,12 +626,22 @@ static void gen_man(struct lls_parse_result *lpr, const char *cmdline)
 	if (suite.commands[0].name.orig) {
 		char date[200];
 		const char *version_string;
-
 		if (!suite.date) {
-			t = time(NULL);
-			tmp = localtime(&t);
+			/*
+			 * If the SOURCE_DATE_EPOCH environment variable
+			 * contains a positive integer in the time_t range, use
+			 * that instead of the current time. See:
+			 * <https://reproducible-builds.org/specs/source-date-epoch/>
+			 * for more information.
+			 */
+			char *source_date_epoch = getenv("SOURCE_DATE_EPOCH");
+			if (source_date_epoch != NULL)
+				t = strtoll(source_date_epoch, NULL, 10);
+			if (t <= 0)
+				t = time(NULL);
+			tmp = gmtime(&t);
 			if (tmp == NULL) {
-				perror("localtime");
+				perror("gmtime");
 				exit(EXIT_FAILURE);
 			}
 			if (strftime(date, sizeof(date), "%B %Y", tmp) == 0) {