handle annotate when renamed file handling is off

fixes #2271

Author: Vladimir Kotal

opengrok-indexer/src/main/java/org/opengrok/indexer/history/GitRepository.java

@@ -351,6 +351,44 @@ protected String findOriginalName(String fullpath, String changeset)
         return (fullpath.substring(0, getDirectoryName().length() + 1) + file);
     }
 
+    /**
+     * Get first revision of given file without following renames.
+     * @param file file to get first revision of
+     */
+    private String getFirstRevision(String fullpath) throws IOException {
+        String[] argv = {
+                ensureCommand(CMD_PROPERTY_KEY, CMD_FALLBACK),
+                "rev-list",
+                "--reverse",
+                "--max-count=1",
+                "HEAD",
+                "--",
+                fullpath
+        };
+
+        Executor executor = new Executor(Arrays.asList(argv), new File(getDirectoryName()),
+                RuntimeEnvironment.getInstance().getInteractiveCommandTimeout());
+        int status = executor.exec();
+
+        try (BufferedReader in = new BufferedReader(
+                new InputStreamReader(executor.getOutputStream()))) {
+            String line;
+
+            if ((line = in.readLine()) != null) {
+                return line.trim();
+            }
+        }
+
+        if (status != 0) {
+            LOGGER.log(Level.WARNING,
+                    "Failed to get first revision for: \"{0}\" Exit code: {1}",
+                    new Object[]{fullpath, String.valueOf(status)});
+            return null;
+        }
+
+        return null;
+    }
+
     /**
      * Annotate the specified file/revision.
      *
@@ -369,15 +407,27 @@ public Annotation annotate(File file, String revision) throws IOException {
         cmd.add(ABBREV_BLAME);
         if (revision != null) {
             cmd.add(revision);
+        } else {
+            // {@code git blame} follows renames by default. If renamed file handling is off, its output would
+            // contain invalid revisions. Therefore, the revision range needs to be constrained.
+            if (!isHandleRenamedFiles()) {
+                String firstRevision = getFirstRevision(file.getAbsolutePath());
+                if (firstRevision == null) {
+                    return null;
+                }
+                cmd.add(firstRevision + "..");
+            }
         }
+        cmd.add("--");
         cmd.add(file.getName());
 
         Executor exec = new Executor(cmd, file.getParentFile(),
                 RuntimeEnvironment.getInstance().getInteractiveCommandTimeout());
         GitAnnotationParser parser = new GitAnnotationParser(file.getName());
         int status = exec.exec(true, parser);
 
-        // File might have changed its location
+        // File might have changed its location if it was renamed.
+        // Try to lookup its original name and get the annotation again.
         if (status != 0) {
             cmd.clear();
             ensureCommand(CMD_PROPERTY_KEY, CMD_FALLBACK);

opengrok-indexer/src/test/java/org/opengrok/indexer/history/GitRepositoryTest.java

@@ -32,6 +32,10 @@
 import java.nio.file.Paths;
 import java.text.DateFormat;
 import java.text.ParseException;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
 import org.junit.After;
 import org.junit.AfterClass;
 import org.junit.Assert;
@@ -200,6 +204,41 @@ public void testRenamedFiles() throws Exception {
         }
     }
 
+    private void testAnnotationOfRenamedFile(GitRepository gitrepo, File file, Set<String> revSet) throws Exception {
+        Annotation annotation = gitrepo.annotate(file, null);
+
+        assertNotNull(annotation);
+        assertEquals(revSet, annotation.getRevisions());
+    }
+
+    @Test
+    public void testAnnotationOfRenamedFileWithHandlingOff() throws Exception {
+        String[] revisions = {"84599b3c"};
+        Set<String> revSet = new HashSet<>();
+        Collections.addAll(revSet, revisions);
+
+        File root = new File(repository.getSourceRoot(), "git");
+        GitRepository gitrepo
+                = (GitRepository) RepositoryFactory.getRepository(root);
+        gitrepo.setHandleRenamedFiles(false);
+        File renamedFile = Paths.get(root.getAbsolutePath(),"moved2", "renamed2.c").toFile();
+        testAnnotationOfRenamedFile(gitrepo, renamedFile, revSet);
+    }
+
+    @Test
+    public void testAnnotationOfRenamedFileWithHandlingOn() throws Exception {
+        String[] revisions = {"1086eaf5", "ce4c98ec"};
+        Set<String> revSet = new HashSet<>();
+        Collections.addAll(revSet, revisions);
+
+        File root = new File(repository.getSourceRoot(), "git");
+        GitRepository gitrepo
+                = (GitRepository) RepositoryFactory.getRepository(root);
+        gitrepo.setHandleRenamedFiles(true);
+        File renamedFile = Paths.get(root.getAbsolutePath(),"moved2", "renamed2.c").toFile();
+        testAnnotationOfRenamedFile(gitrepo, renamedFile, revSet);
+    }
+
     @Test(expected = IOException.class)
     public void testInvalidRenamedFiles() throws Exception {
         String[][] tests = new String[][]{