MB-32840: Prevent crash when rotating empty audit log

BP of MB-32231: http://review.couchbase.org/#/c/102432/

Change-Id: I5db72afaca6bc627a618d1cbbdbc6ae5173d3810
Reviewed-on: http://review.couchbase.org/104202
Well-Formed: Build Bot <[email protected]>
Tested-by: Build Bot <[email protected]>
Reviewed-by: Dave Rigby <[email protected]>

Author: trondn

auditd/src/auditfile.h

@@ -53,7 +53,7 @@ class AuditFile {
                 // closing and then re-opening we can just keep open and
                 // update the open_time.
                 open_time = auditd_time();
-                return true;
+                return false;
             }
             close_and_rotate_log();
             return true;

auditd/tests/auditfile_test.cc

@@ -82,6 +82,28 @@ TEST_F(AuditFileTest, TestFileCreation) {
     EXPECT_EQ(1, files.size());
 }
 
+/**
+ * Test that an empty file is properly rotated using ensure_open()
+ * Seen issues in the past such as MB-32232
+ */
+TEST_F(AuditFileTest, TestRotateEmptyFile) {
+    AuditConfig defaultvalue;
+    config.set_rotate_interval(defaultvalue.get_min_file_rotation_time());
+    config.set_rotate_size(1024*1024);
+
+    AuditFile auditfile;
+    auditfile.reconfigure(config);
+
+    auditfile.ensure_open();
+    cb_timeofday_timetravel(defaultvalue.get_min_file_rotation_time() + 1);
+    auditfile.ensure_open();
+
+    auditfile.close();
+
+    auto files = findFilesWithPrefix(testdir + "/testing");
+    EXPECT_EQ(0, files.size());
+}
+
 /**
  * Test that we can create a file, and as time flies by we rotate
  * to use the next file