From 22588250baa1bfa5c00f57d39329d0c144fc8112 Mon Sep 17 00:00:00 2001
From: Florian Festi <ffesti@redhat.com>
Date: Thu, 2 Jun 2016 15:54:01 +0200
Subject: [PATCH] Add support for _buildhost macro for setting the build host
 manually.

This is useful for reproducible builds. See rhbz#1309367.
---
 build/pack.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/build/pack.c b/build/pack.c
index f9fb3a0..82c1262 100644
--- a/build/pack.c
+++ b/build/pack.c
@@ -179,16 +179,25 @@ static const char * buildHost(void)
     static char hostname[1024];
     static int oneshot = 0;
     struct hostent *hbn;
+    char *bhMacro;
 
     if (! oneshot) {
-        (void) gethostname(hostname, sizeof(hostname));
-	hbn = gethostbyname(hostname);
-	if (hbn)
-	    strcpy(hostname, hbn->h_name);
-	else
-	    rpmlog(RPMLOG_WARNING,
-			_("Could not canonicalize hostname: %s\n"), hostname);
-	oneshot = 1;
+        bhMacro = rpmExpand("%{?_buildhost}", NULL);
+        if (strcmp(bhMacro, "") != 0 && strlen(bhMacro) < 1024) {
+            strcpy(hostname, bhMacro);
+        } else {
+            if (strcmp(bhMacro, "") != 0)
+                rpmlog(RPMLOG_WARNING, _("The _buildhost macro is too long\n"));
+            (void) gethostname(hostname, sizeof(hostname));
+            hbn = gethostbyname(hostname);
+            if (hbn)
+                strcpy(hostname, hbn->h_name);
+            else
+                rpmlog(RPMLOG_WARNING,
+                        _("Could not canonicalize hostname: %s\n"), hostname);
+        }
+        free(bhMacro);
+        oneshot = 1;
     }
     return(hostname);
 }
-- 
2.5.5