Disable gc_log file for in-memory acceptance tests

Change-Id: I316761b522e4336e7a736594ac74c56ea2da2b37
diff --git a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/GerritServer.java b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/GerritServer.java
index 644a4bb..3be8195 100644
--- a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/GerritServer.java
+++ b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/GerritServer.java
@@ -22,6 +22,7 @@
 import com.google.gerrit.server.config.GerritServerConfig;
 import com.google.gerrit.server.index.ChangeSchemas;
 import com.google.gerrit.server.util.SocketUtil;
+import com.google.gerrit.server.util.SystemLog;
 import com.google.gerrit.testutil.TempFileUtil;
 import com.google.inject.Injector;
 import com.google.inject.Key;
@@ -70,6 +71,9 @@
     if (memory) {
       site = null;
       mergeTestConfig(cfg);
+      // Set the log4j configuration to an invalid one to prevent system logs
+      // from getting configured and creating log files.
+      System.setProperty(SystemLog.LOG4J_CONFIGURATION, "invalidConfiguration");
       cfg.setBoolean("httpd", null, "requestLog", false);
       cfg.setBoolean("sshd", null, "requestLog", false);
       cfg.setBoolean("index", "lucene", "testInmemory", true);
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/util/SystemLog.java b/gerrit-server/src/main/java/com/google/gerrit/server/util/SystemLog.java
index ba31f56..cf7f11f 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/util/SystemLog.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/util/SystemLog.java
@@ -38,10 +38,11 @@
 
 @Singleton
 public class SystemLog {
+  private static final org.slf4j.Logger log =
+      LoggerFactory.getLogger(SystemLog.class);
 
-  private static final org.slf4j.Logger log = LoggerFactory
-      .getLogger(SystemLog.class);
-  private static final String LOG4J_CONFIGURATION = "log4j.configuration";
+  public static final String LOG4J_CONFIGURATION = "log4j.configuration";
+
   private final SitePaths site;
   private final Config config;