Reject test run if the patchset isn't the most current

This happens if the job is added to jenkins queue and then patchset is
updated/rebased before the job is run.

Patch will stop running tests on obsolete patchset
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>

jenkins/gerrit_query.php

@@ -8,7 +8,7 @@
 $git_commit_id = $argv[2];
 $first_commit = $argv[3];
 $ch = curl_init();
-curl_setopt($ch, CURLOPT_URL, 'https://reviews.mahara.org/changes/?q=' . $git_commit_id . '&o=LABELS&pp=0');
+curl_setopt($ch, CURLOPT_URL, 'https://reviews.mahara.org/changes/?q=' . $git_commit_id . '&o=LABELS&o=CURRENT_REVISION&pp=0');
 curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
 $content = curl_exec($ch);
 curl_close($ch);
@@ -21,6 +21,12 @@ if ($content[0]->status == 'MERGED') {
     exit;
 }
 
+// Check that the patch we are testing is the latest (current) patchset in series
+if ($content[0]->current_revision != $git_commit_id) {
+    echo 3;
+    exit;
+}
+
 // Now check to see if anyone has rejected this.
 // We don't want to reject the patch if auto test has failed as we are re-testing now
 // but we do want to reject patch if the parent has failed auto test.

jenkins/mahara_jenkins.sh

@@ -29,6 +29,9 @@ do
         if [ "$outcome" = "1" ]; then
             echo "The patch with git commit id $line has been rejected"
             exit 1;
+        elif [ "$outcome" = "3" ]; then
+            echo "The patch with git commit id $line is not the latest (current) patch"
+            exit 1;
         else
             echo "The patch with git commit id $line looks ok so we will continue"
         fi