fix strange failure of testPerProjectHistory

The problem would appear randomly, caused by invalid HistoryGuru state -
the repository map contained duplicate entries with different settings.

This requires some methods to be available so that the state is refreshed
for each run.

Also, parametrize the test properly.

Author: vladak

opengrok-indexer/src/test/java/org/opengrok/indexer/index/IndexerRepoTest.java

@@ -18,7 +18,7 @@
  */
 
 /*
- * Copyright (c) 2014, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2022, Oracle and/or its affiliates. All rights reserved.
  * Portions Copyright (c) 2017, 2019, Chris Fraire <cfraire@me.com>.
  */
 package org.opengrok.indexer.index;
@@ -43,6 +43,8 @@
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.opengrok.indexer.condition.EnabledForRepository;
 import org.opengrok.indexer.configuration.Project;
 import org.opengrok.indexer.configuration.RuntimeEnvironment;
@@ -57,7 +59,7 @@
  * Test indexer w.r.t. repositories.
  * @author Vladimir Kotal
  */
-public class IndexerRepoTest {
+class IndexerRepoTest {
 
     private TestRepository repository;
 
@@ -73,25 +75,10 @@ public void tearDown() {
         repository.destroy();
     }
 
-    /**
-     * Test it is possible to disable history per project.
-     */
-    @Test
     @EnabledForRepository(MERCURIAL)
-    public void testPerProjectHistoryGlobalOn() throws IndexerException, IOException, HistoryException {
-        testPerProjectHistory(true);
-    }
-
-    /**
-     * Test it is possible to enable history per project.
-     */
-    @Test
-    @EnabledForRepository(MERCURIAL)
-    public void testPerProjectHistoryGlobalOff() throws IndexerException, IOException, HistoryException {
-        testPerProjectHistory(false);
-    }
-
-    private void testPerProjectHistory(boolean globalOn) throws IndexerException, IOException, HistoryException {
+    @ParameterizedTest
+    @ValueSource(booleans = {false, true})
+    void testPerProjectHistory(boolean globalOn) throws IndexerException, IOException, HistoryException {
         RuntimeEnvironment env = RuntimeEnvironment.getInstance();
 
         // Make sure we start from scratch.
@@ -100,19 +87,25 @@ private void testPerProjectHistory(boolean globalOn) throws IndexerException, IO
         env.setProjectsEnabled(true);
         env.setHistoryEnabled(globalOn);
 
+        // The projects have to be added first so that prepareIndexer() can use their configuration.
         Project proj = new Project("mercurial", "/mercurial");
         proj.setHistoryEnabled(!globalOn);
         env.getProjects().clear();
         env.getProjects().put("mercurial", proj);
+        proj = new Project("git", "/git");
+        env.getProjects().put("git", proj);
 
+        HistoryGuru.getInstance().clear();
         Indexer.getInstance().prepareIndexer(
                 env,
                 true, // search for repositories
                 true, // scan and add projects
                 false, // don't create dictionary
                 null, // subFiles - not needed since we don't list files
                 null); // repositories - not needed when not refreshing history
+        env.generateProjectRepositoriesMap();
 
+        // The repositories of the git project should follow the global history setting.
         File repoRoot = new File(env.getSourceRootFile(), "git");
         File fileInRepo = new File(repoRoot, "main.c");
         assertTrue(fileInRepo.exists());
@@ -122,6 +115,7 @@ private void testPerProjectHistory(boolean globalOn) throws IndexerException, IO
             assertNull(HistoryGuru.getInstance().getHistory(fileInRepo));
         }
 
+        // The repositories of the mercurial project should be opposite to the global history setting.
         repoRoot = new File(env.getSourceRootFile(), "mercurial");
         fileInRepo = new File(repoRoot, "main.c");
         assertTrue(fileInRepo.exists());
@@ -140,7 +134,7 @@ private void testPerProjectHistory(boolean globalOn) throws IndexerException, IO
      */
     @EnabledForRepository(MERCURIAL)
     @Test
-    public void testSymlinks() throws IndexerException, IOException {
+    void testSymlinks() throws IndexerException, IOException {
 
         final String SYMLINK = "symlink";
         RuntimeEnvironment env = RuntimeEnvironment.getInstance();