Add some trivial tests for git-if-needed.
Change-Id: I5f8fde2aebb3ab051aa5afbc7d5a093f454cfbbb
diff --git a/tools/git-if-needed/tests/data/modify-readme.patch b/tools/git-if-needed/tests/data/modify-readme.patch
new file mode 100644
index 0000000..101253e
--- /dev/null
+++ b/tools/git-if-needed/tests/data/modify-readme.patch
@@ -0,0 +1,22 @@
+From 1616666e77742002b1d02b8bdd3092048cfa3f3f Mon Sep 17 00:00:00 2001
+From: Peter Penchev <openstack-dev@storpool.com>
+Date: Fri, 29 Nov 2019 23:24:27 +0200
+Subject: [PATCH 2/2] Make a change to the README file.
+
+Change-Id: I7b1587d3f10e717fc4d28b51aac38ae9247fc843
+---
+ README.txt | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/README.txt b/README.txt
+index e16c97f..38358ac 100644
+--- a/README.txt
++++ b/README.txt
+@@ -1,2 +1,4 @@
+ This is a sample Git repository for testing the operation of
+ the git-if-needed tool.
++
++No need to wonder about the meaning behind it all, is there?
+--
+2.24.0
+