From 6493d30df81c7a8ec87e2b04b2418a920b50e611 Mon Sep 17 00:00:00 2001
From: Rhys Smith <rhys.smith@jisc.ac.uk>
Date: Thu, 11 Aug 2016 16:45:15 +0100
Subject: [PATCH] Make Git merges succeed only when fast forwarding. Closes #13

---
 build.xml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/build.xml b/build.xml
index 2a2b6f5d..0671c8b6 100644
--- a/build.xml
+++ b/build.xml
@@ -702,6 +702,7 @@
         <exec executable="${git.executable}" dir="${shared.ws.dir}/${git.repo.project.data}" failonerror="true">
             <arg value="merge"/>
             <arg value="deferred"/>
+            <arg value="--ff-only"/>
             <arg value="-m"/>
             <arg value="'Merging deferred branch into immediate branch.'"/>
         </exec>
@@ -719,6 +720,7 @@
         <exec executable="${git.executable}" dir="${shared.ws.dir}/${git.repo.project.data}" failonerror="true">
             <arg value="merge"/>
             <arg value="immediate"/>
+            <arg value="--ff-only"/>
             <arg value="-m"/>
             <arg value="'Merging immediate branch into master branch.'"/>
         </exec>
@@ -736,6 +738,7 @@
         <exec executable="${git.executable}" dir="${shared.ws.dir}/${git.repo.project.data}" failonerror="true">
             <arg value="merge"/>
             <arg value="master"/>
+            <arg value="--ff-only"/>
             <arg value="-m"/>
             <arg value="'Merging master branch into immediate branch.'"/>
         </exec>
@@ -753,6 +756,7 @@
         <exec executable="${git.executable}" dir="${shared.ws.dir}/${git.repo.project.data}" failonerror="true">
             <arg value="merge"/>
             <arg value="immediate"/>
+            <arg value="--ff-only"/>
             <arg value="-m"/>
             <arg value="'Merging immedate branch into deferred branch.'"/>
         </exec>
@@ -770,6 +774,7 @@
         <exec executable="${git.executable}" dir="${shared.ws.dir}/${git.repo.project.data}" failonerror="true">
             <arg value="merge"/>
             <arg value="master"/>
+            <arg value="--ff-only"/>
             <arg value="-m"/>
             <arg value="'Merging immedate branch into deferred branch.'"/>
         </exec>
@@ -787,6 +792,7 @@
         <exec executable="${git.executable}" dir="${shared.ws.dir}/${git.repo.project.data}" failonerror="true">
             <arg value="merge"/>
             <arg value="deferred"/>
+            <arg value="--ff-only"/>
             <arg value="-m"/>
             <arg value="'Merging immedate branch into deferred branch.'"/>
         </exec>