diff --git a/java/com/google/gerrit/server/approval/ApprovalInference.java b/java/com/google/gerrit/server/approval/ApprovalInference.java
index 27870a1..fba2fcb 100644
--- a/java/com/google/gerrit/server/approval/ApprovalInference.java
+++ b/java/com/google/gerrit/server/approval/ApprovalInference.java
@@ -40,7 +40,7 @@
 import com.google.gerrit.server.patch.DiffNotAvailableException;
 import com.google.gerrit.server.patch.DiffOperations;
 import com.google.gerrit.server.patch.DiffOptions;
-import com.google.gerrit.server.patch.filediff.FileDiffOutput;
+import com.google.gerrit.server.patch.gitdiff.ModifiedFile;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectState;
 import com.google.gerrit.server.query.approval.ApprovalContext;
@@ -126,9 +126,9 @@
       PatchSet.Id psId,
       ChangeKind kind,
       LabelType type,
-      @Nullable Map<String, FileDiffOutput> baseVsCurrentDiff,
-      @Nullable Map<String, FileDiffOutput> baseVsPriorDiff,
-      @Nullable Map<String, FileDiffOutput> priorVsCurrentDiff) {
+      @Nullable Map<String, ModifiedFile> baseVsCurrentDiff,
+      @Nullable Map<String, ModifiedFile> baseVsPriorDiff,
+      @Nullable Map<String, ModifiedFile> priorVsCurrentDiff) {
     int n = psa.key().patchSetId().get();
     checkArgument(n != psId.get());
 
@@ -316,11 +316,14 @@
       PatchSetApproval psa,
       PatchSet patchSet,
       LabelType type,
-      ChangeKind changeKind) {
+      ChangeKind changeKind,
+      RevWalk revWalk,
+      Config repoConfig) {
     if (!type.getCopyCondition().isPresent()) {
       return false;
     }
-    ApprovalContext ctx = ApprovalContext.create(changeNotes, psa, patchSet, changeKind);
+    ApprovalContext ctx =
+        ApprovalContext.create(changeNotes, psa, patchSet, changeKind, revWalk, repoConfig);
     try {
       // Use a request context to run checks as an internal user with expanded visibility. This is
       // so that the output of the copy condition does not depend on who is running the current
@@ -381,9 +384,9 @@
         priorPatchSet.getValue().id().changeId(),
         changeKind);
 
-    Map<String, FileDiffOutput> baseVsCurrent = null;
-    Map<String, FileDiffOutput> baseVsPrior = null;
-    Map<String, FileDiffOutput> priorVsCurrent = null;
+    Map<String, ModifiedFile> baseVsCurrent = null;
+    Map<String, ModifiedFile> baseVsPrior = null;
+    Map<String, ModifiedFile> priorVsCurrent = null;
     LabelTypes labelTypes = project.getLabelTypes();
     for (PatchSetApproval psa : priorApprovalsIncludingCopied) {
       if (resultByUser.contains(psa.label(), psa.accountId())) {
@@ -394,10 +397,11 @@
       if (baseVsCurrent == null
           && type.isPresent()
           && type.get().isCopyAllScoresIfListOfFilesDidNotChange()) {
-        baseVsCurrent = listModifiedFiles(project, patchSet);
-        baseVsPrior = listModifiedFiles(project, priorPatchSet.getValue());
+        baseVsCurrent = listModifiedFiles(project, patchSet, rw, repoConfig);
+        baseVsPrior = listModifiedFiles(project, priorPatchSet.getValue(), rw, repoConfig);
         priorVsCurrent =
-            listModifiedFiles(project, priorPatchSet.getValue().commitId(), patchSet.commitId());
+            listModifiedFiles(
+                project, priorPatchSet.getValue().commitId(), patchSet.commitId(), rw, repoConfig);
       }
       if (!type.isPresent()) {
         logger.atFine().log(
@@ -420,7 +424,8 @@
               baseVsCurrent,
               baseVsPrior,
               priorVsCurrent)
-          && !canCopyBasedOnCopyCondition(notes, psa, patchSet, type.get(), changeKind)) {
+          && !canCopyBasedOnCopyCondition(
+              notes, psa, patchSet, type.get(), changeKind, rw, repoConfig)) {
         continue;
       }
       resultByUser.put(psa.label(), psa.accountId(), psa.copyWithPatchSet(patchSet.id()));
@@ -432,14 +437,20 @@
    * Gets the modified files between the two latest patch-sets. Can be used to compute difference in
    * files between those two patch-sets .
    */
-  private Map<String, FileDiffOutput> listModifiedFiles(ProjectState project, PatchSet ps) {
+  private Map<String, ModifiedFile> listModifiedFiles(
+      ProjectState project, PatchSet ps, RevWalk revWalk, Config repoConfig) {
     try {
       Integer parentNum =
           listOfFilesUnchangedPredicate.isInitialCommit(project.getNameKey(), ps.commitId())
               ? 0
               : 1;
-      return diffOperations.listModifiedFilesAgainstParent(
-          project.getNameKey(), ps.commitId(), parentNum, DiffOptions.DEFAULTS);
+      return diffOperations.loadModifiedFilesAgainstParent(
+          project.getNameKey(),
+          ps.commitId(),
+          parentNum,
+          DiffOptions.DEFAULTS,
+          revWalk,
+          repoConfig);
     } catch (DiffNotAvailableException ex) {
       throw new StorageException(
           "failed to compute difference in files, so won't copy"
@@ -453,11 +464,20 @@
    * Gets the modified files between two commits corresponding to different patchsets of the same
    * change.
    */
-  private Map<String, FileDiffOutput> listModifiedFiles(
-      ProjectState project, ObjectId sourceCommit, ObjectId targetCommit) {
+  private Map<String, ModifiedFile> listModifiedFiles(
+      ProjectState project,
+      ObjectId sourceCommit,
+      ObjectId targetCommit,
+      RevWalk revWalk,
+      Config repoConfig) {
     try {
-      return diffOperations.listModifiedFiles(
-          project.getNameKey(), sourceCommit, targetCommit, DiffOptions.DEFAULTS);
+      return diffOperations.loadModifiedFiles(
+          project.getNameKey(),
+          sourceCommit,
+          targetCommit,
+          DiffOptions.DEFAULTS,
+          revWalk,
+          repoConfig);
     } catch (DiffNotAvailableException ex) {
       throw new StorageException(
           "failed to compute difference in files, so won't copy"
diff --git a/java/com/google/gerrit/server/patch/DiffOperations.java b/java/com/google/gerrit/server/patch/DiffOperations.java
index c84186d..a265337 100644
--- a/java/com/google/gerrit/server/patch/DiffOperations.java
+++ b/java/com/google/gerrit/server/patch/DiffOperations.java
@@ -18,10 +18,14 @@
 import com.google.gerrit.entities.Patch;
 import com.google.gerrit.entities.Patch.ChangeType;
 import com.google.gerrit.entities.Project;
+import com.google.gerrit.entities.Project.NameKey;
 import com.google.gerrit.extensions.client.DiffPreferencesInfo;
 import com.google.gerrit.server.patch.filediff.FileDiffOutput;
+import com.google.gerrit.server.patch.gitdiff.ModifiedFile;
 import java.util.Map;
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.revwalk.RevWalk;
 
 /**
  * An interface for all file diff related operations. Clients should use this interface to request:
@@ -60,6 +64,29 @@
       throws DiffNotAvailableException;
 
   /**
+   * This method is similar to {@link #listModifiedFilesAgainstParent(NameKey, ObjectId, int,
+   * DiffOptions)} but loads the modified files directly instead of retrieving them from the diff
+   * cache.
+   *
+   * <p>A RevWalk and repoConfig are also supplied and are used to look up the commit IDs. This is
+   * useful in case one the commits is currently being created, that's why the {@code revWalk}
+   * parameter is needed.
+   *
+   * <p>Note that rename detection is disabled for this method.
+   *
+   * @return a map of file paths to {@link ModifiedFile}. The {@link ModifiedFile} contains the
+   *     old/new file paths and the change type (added, deleted, etc...).
+   */
+  Map<String, ModifiedFile> loadModifiedFilesAgainstParent(
+      Project.NameKey project,
+      ObjectId newCommit,
+      int parentNum,
+      DiffOptions diffOptions,
+      RevWalk revWalk,
+      Config repoConfig)
+      throws DiffNotAvailableException;
+
+  /**
    * Returns the list of added, deleted or modified files between two commits (patchsets). The
    * commit message and merge list (for merge commits) are also returned.
    *
@@ -77,6 +104,29 @@
       throws DiffNotAvailableException;
 
   /**
+   * This method is similar to {@link #listModifiedFilesAgainstParent(NameKey, ObjectId, int,
+   * DiffOptions)} but loads the modified files directly instead of retrieving them from the diff
+   * cache.
+   *
+   * <p>A RevWalk and repoConfig are also supplied and are used to look up the commit IDs. This is
+   * useful in case one the commits is currently being created, that's why the {@code revWalk}
+   * parameter is needed.
+   *
+   * <p>Note that rename detection is disabled for this method.
+   *
+   * @return a map of file paths to {@link ModifiedFile}. The {@link ModifiedFile} contains the
+   *     old/new file paths and the change type (added, deleted, etc...).
+   */
+  Map<String, ModifiedFile> loadModifiedFiles(
+      Project.NameKey project,
+      ObjectId oldCommit,
+      ObjectId newCommit,
+      DiffOptions diffOptions,
+      RevWalk revWalk,
+      Config repoConfig)
+      throws DiffNotAvailableException;
+
+  /**
    * Returns the diff for a single file between a patchset commit against its parent or the
    * auto-merge commit. For deleted files, the {@code fileName} parameter should contain the old
    * name of the file. This method will return {@link FileDiffOutput#empty(String, ObjectId,
diff --git a/java/com/google/gerrit/server/patch/DiffOperationsImpl.java b/java/com/google/gerrit/server/patch/DiffOperationsImpl.java
index 3d230f8..012a91c 100644
--- a/java/com/google/gerrit/server/patch/DiffOperationsImpl.java
+++ b/java/com/google/gerrit/server/patch/DiffOperationsImpl.java
@@ -47,7 +47,15 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
+import java.util.function.Function;
+import org.eclipse.jgit.diff.DiffEntry;
+import org.eclipse.jgit.diff.DiffFormatter;
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectReader;
+import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.util.io.DisabledOutputStream;
 
 /**
  * Provides different file diff operations. Uses the underlying Git/Gerrit caches to speed up the
@@ -57,6 +65,19 @@
 public class DiffOperationsImpl implements DiffOperations {
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
+  private static final ImmutableMap<DiffEntry.ChangeType, Patch.ChangeType> changeTypeMap =
+      ImmutableMap.of(
+          DiffEntry.ChangeType.ADD,
+          Patch.ChangeType.ADDED,
+          DiffEntry.ChangeType.MODIFY,
+          Patch.ChangeType.MODIFIED,
+          DiffEntry.ChangeType.DELETE,
+          Patch.ChangeType.DELETED,
+          DiffEntry.ChangeType.RENAME,
+          Patch.ChangeType.RENAMED,
+          DiffEntry.ChangeType.COPY,
+          Patch.ChangeType.COPIED);
+
   private static final int RENAME_SCORE = 60;
   private static final DiffAlgorithm DEFAULT_DIFF_ALGORITHM =
       DiffAlgorithm.HISTOGRAM_WITH_FALLBACK_MYERS;
@@ -103,6 +124,27 @@
   }
 
   @Override
+  public Map<String, ModifiedFile> loadModifiedFilesAgainstParent(
+      Project.NameKey project,
+      ObjectId newCommit,
+      int parentNum,
+      DiffOptions diffOptions,
+      RevWalk revWalk,
+      Config repoConfig)
+      throws DiffNotAvailableException {
+    try {
+      DiffParameters diffParams = computeDiffParameters(project, newCommit, parentNum);
+      return loadModifiedFilesWithoutCache(project, diffParams, revWalk, repoConfig);
+    } catch (IOException e) {
+      throw new DiffNotAvailableException(
+          String.format(
+              "Failed to evaluate the parent/base commit for commit '%s' with parentNum=%d",
+              newCommit, parentNum),
+          e);
+    }
+  }
+
+  @Override
   public Map<String, FileDiffOutput> listModifiedFiles(
       Project.NameKey project, ObjectId oldCommit, ObjectId newCommit, DiffOptions diffOptions)
       throws DiffNotAvailableException {
@@ -117,6 +159,25 @@
   }
 
   @Override
+  public Map<String, ModifiedFile> loadModifiedFiles(
+      Project.NameKey project,
+      ObjectId oldCommit,
+      ObjectId newCommit,
+      DiffOptions diffOptions,
+      RevWalk revWalk,
+      Config repoConfig)
+      throws DiffNotAvailableException {
+    DiffParameters params =
+        DiffParameters.builder()
+            .project(project)
+            .newCommit(newCommit)
+            .baseCommit(oldCommit)
+            .comparisonType(ComparisonType.againstOtherPatchSet())
+            .build();
+    return loadModifiedFilesWithoutCache(project, params, revWalk, repoConfig);
+  }
+
+  @Override
   public FileDiffOutput getModifiedFileAgainstParent(
       Project.NameKey project,
       ObjectId newCommit,
@@ -329,6 +390,50 @@
         .build();
   }
 
+  /** Loads the modified file paths between two commits without inspecting the diff cache. */
+  private static Map<String, ModifiedFile> loadModifiedFilesWithoutCache(
+      Project.NameKey project, DiffParameters diffParams, RevWalk revWalk, Config repoConfig)
+      throws DiffNotAvailableException {
+    ObjectId newCommit = diffParams.newCommit();
+    ObjectId oldCommit = diffParams.baseCommit();
+    try {
+      ObjectReader reader = revWalk.getObjectReader();
+      List<DiffEntry> diffEntries;
+      try (DiffFormatter df = new DiffFormatter(DisabledOutputStream.INSTANCE)) {
+        df.setReader(reader, repoConfig);
+        df.setDetectRenames(false);
+        diffEntries = df.scan(oldCommit.equals(ObjectId.zeroId()) ? null : oldCommit, newCommit);
+      }
+      return diffEntries.stream()
+          .map(
+              entry ->
+                  ModifiedFile.builder()
+                      .changeType(toChangeType(entry.getChangeType()))
+                      .oldPath(getGitPath(entry.getOldPath()))
+                      .newPath(getGitPath(entry.getNewPath()))
+                      .build())
+          .collect(ImmutableMap.toImmutableMap(ModifiedFile::getDefaultPath, Function.identity()));
+    } catch (IOException e) {
+      throw new DiffNotAvailableException(
+          String.format(
+              "Failed to compute the modified files for project '%s',"
+                  + " old commit '%s', new commit '%s'.",
+              project, oldCommit.name(), newCommit.name()),
+          e);
+    }
+  }
+
+  private static Optional<String> getGitPath(String path) {
+    return path.equals(DiffEntry.DEV_NULL) ? Optional.empty() : Optional.of(path);
+  }
+
+  private static Patch.ChangeType toChangeType(DiffEntry.ChangeType changeType) {
+    if (!changeTypeMap.containsKey(changeType)) {
+      throw new IllegalArgumentException("Unsupported type " + changeType);
+    }
+    return changeTypeMap.get(changeType);
+  }
+
   @AutoValue
   abstract static class DiffParameters {
     abstract Project.NameKey project();
diff --git a/java/com/google/gerrit/server/patch/gitdiff/ModifiedFile.java b/java/com/google/gerrit/server/patch/gitdiff/ModifiedFile.java
index f4e7ca3..3596a54 100644
--- a/java/com/google/gerrit/server/patch/gitdiff/ModifiedFile.java
+++ b/java/com/google/gerrit/server/patch/gitdiff/ModifiedFile.java
@@ -47,6 +47,10 @@
    */
   public abstract Optional<String> newPath();
 
+  public String getDefaultPath() {
+    return newPath().isPresent() ? newPath().get() : oldPath().get();
+  }
+
   public static Builder builder() {
     return new AutoValue_ModifiedFile.Builder();
   }
diff --git a/java/com/google/gerrit/server/query/approval/ApprovalContext.java b/java/com/google/gerrit/server/query/approval/ApprovalContext.java
index 4dedbb5..2839eb7 100644
--- a/java/com/google/gerrit/server/query/approval/ApprovalContext.java
+++ b/java/com/google/gerrit/server/query/approval/ApprovalContext.java
@@ -21,6 +21,8 @@
 import com.google.gerrit.entities.PatchSetApproval;
 import com.google.gerrit.extensions.client.ChangeKind;
 import com.google.gerrit.server.notedb.ChangeNotes;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.revwalk.RevWalk;
 
 /** Entity representing all required information to match predicates for copying approvals. */
 @AutoValue
@@ -41,8 +43,19 @@
   /** {@link ChangeKind} of the delta between the origin and target patch set. */
   public abstract ChangeKind changeKind();
 
+  /** {@link RevWalk} of the repository for the current commit. */
+  public abstract RevWalk revWalk();
+
+  /** {@link RevWalk} of the repository for the current commit. */
+  public abstract Config repoConfig();
+
   public static ApprovalContext create(
-      ChangeNotes changeNotes, PatchSetApproval psa, PatchSet patchSet, ChangeKind changeKind) {
+      ChangeNotes changeNotes,
+      PatchSetApproval psa,
+      PatchSet patchSet,
+      ChangeKind changeKind,
+      RevWalk revWalk,
+      Config repoConfig) {
     checkState(
         psa.patchSetId().changeId().equals(patchSet.id().changeId()),
         "approval and target must be the same change. got: %s, %s",
@@ -54,6 +67,7 @@
     // As explained in the commit message of this change doing this check is only possible if there
     // are no changes with gaps in patch set numbers. Since it's planned to fix-up old changes with
     // gaps in patch set numbers, this todo is a reminder to add back the check once this is done.
-    return new AutoValue_ApprovalContext(psa, patchSet, changeNotes, changeKind);
+    return new AutoValue_ApprovalContext(
+        psa, patchSet, changeNotes, changeKind, revWalk, repoConfig);
   }
 }
diff --git a/java/com/google/gerrit/server/query/approval/ListOfFilesUnchangedPredicate.java b/java/com/google/gerrit/server/query/approval/ListOfFilesUnchangedPredicate.java
index c35fa1c..2a72c49 100644
--- a/java/com/google/gerrit/server/query/approval/ListOfFilesUnchangedPredicate.java
+++ b/java/com/google/gerrit/server/query/approval/ListOfFilesUnchangedPredicate.java
@@ -24,7 +24,7 @@
 import com.google.gerrit.server.patch.DiffNotAvailableException;
 import com.google.gerrit.server.patch.DiffOperations;
 import com.google.gerrit.server.patch.DiffOptions;
-import com.google.gerrit.server.patch.filediff.FileDiffOutput;
+import com.google.gerrit.server.patch.gitdiff.ModifiedFile;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import java.io.IOException;
@@ -59,24 +59,30 @@
     Integer parentNum =
         isInitialCommit(ctx.changeNotes().getProjectName(), targetPatchSet.commitId()) ? 0 : 1;
     try {
-      Map<String, FileDiffOutput> baseVsCurrent =
-          diffOperations.listModifiedFilesAgainstParent(
+      Map<String, ModifiedFile> baseVsCurrent =
+          diffOperations.loadModifiedFilesAgainstParent(
               ctx.changeNotes().getProjectName(),
               targetPatchSet.commitId(),
               parentNum,
-              DiffOptions.DEFAULTS);
-      Map<String, FileDiffOutput> baseVsPrior =
-          diffOperations.listModifiedFilesAgainstParent(
+              DiffOptions.DEFAULTS,
+              ctx.revWalk(),
+              ctx.repoConfig());
+      Map<String, ModifiedFile> baseVsPrior =
+          diffOperations.loadModifiedFilesAgainstParent(
               ctx.changeNotes().getProjectName(),
               sourcePatchSet.commitId(),
               parentNum,
-              DiffOptions.DEFAULTS);
-      Map<String, FileDiffOutput> priorVsCurrent =
-          diffOperations.listModifiedFiles(
+              DiffOptions.DEFAULTS,
+              ctx.revWalk(),
+              ctx.repoConfig());
+      Map<String, ModifiedFile> priorVsCurrent =
+          diffOperations.loadModifiedFiles(
               ctx.changeNotes().getProjectName(),
               sourcePatchSet.commitId(),
               targetPatchSet.commitId(),
-              DiffOptions.DEFAULTS);
+              DiffOptions.DEFAULTS,
+              ctx.revWalk(),
+              ctx.repoConfig());
       return match(baseVsCurrent, baseVsPrior, priorVsCurrent);
     } catch (DiffNotAvailableException ex) {
       throw new StorageException(
@@ -92,9 +98,9 @@
    * {@link ChangeType} matches for each modified file.
    */
   public boolean match(
-      Map<String, FileDiffOutput> baseVsCurrent,
-      Map<String, FileDiffOutput> baseVsPrior,
-      Map<String, FileDiffOutput> priorVsCurrent) {
+      Map<String, ModifiedFile> baseVsCurrent,
+      Map<String, ModifiedFile> baseVsPrior,
+      Map<String, ModifiedFile> priorVsCurrent) {
     Set<String> allFiles = new HashSet<>();
     allFiles.addAll(baseVsCurrent.keySet());
     allFiles.addAll(baseVsPrior.keySet());
@@ -102,17 +108,17 @@
       if (Patch.isMagic(file)) {
         continue;
       }
-      FileDiffOutput fileDiffOutput1 = baseVsCurrent.get(file);
-      FileDiffOutput fileDiffOutput2 = baseVsPrior.get(file);
+      ModifiedFile modifiedFile1 = baseVsCurrent.get(file);
+      ModifiedFile modifiedFile2 = baseVsPrior.get(file);
       if (!priorVsCurrent.containsKey(file)) {
         // If the file is not modified between prior and current patchsets, then scan safely skip
-        // it. The file might has been modified due to rebase.
+        // it. The file might have been modified due to rebase.
         continue;
       }
-      if (fileDiffOutput1 == null || fileDiffOutput2 == null) {
+      if (modifiedFile1 == null || modifiedFile2 == null) {
         return false;
       }
-      if (!fileDiffOutput2.changeType().equals(fileDiffOutput1.changeType())) {
+      if (!modifiedFile2.changeType().equals(modifiedFile1.changeType())) {
         return false;
       }
     }
diff --git a/javatests/com/google/gerrit/acceptance/server/query/ApprovalQueryIT.java b/javatests/com/google/gerrit/acceptance/server/query/ApprovalQueryIT.java
index 537c7d8..97f072e 100644
--- a/javatests/com/google/gerrit/acceptance/server/query/ApprovalQueryIT.java
+++ b/javatests/com/google/gerrit/acceptance/server/query/ApprovalQueryIT.java
@@ -36,6 +36,8 @@
 import com.google.gerrit.server.query.approval.ApprovalQueryBuilder;
 import com.google.inject.Inject;
 import java.util.Date;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.revwalk.RevWalk;
 import org.junit.Test;
 
 public class ApprovalQueryIT extends AbstractDaemonTest {
@@ -250,7 +252,7 @@
   }
 
   private ApprovalContext contextForCodeReviewLabel(
-      int value, PatchSet.Id psId, Account.Id approver) {
+      int value, PatchSet.Id psId, Account.Id approver) throws Exception {
     ChangeNotes changeNotes = changeNotesFactory.create(project, psId.changeId());
     PatchSet.Id newPsId = PatchSet.id(psId.changeId(), psId.get() + 1);
     ChangeKind changeKind =
@@ -263,7 +265,15 @@
             .key(PatchSetApproval.key(psId, approver, LabelId.create("Code-Review")))
             .value(value)
             .build();
-    return ApprovalContext.create(
-        changeNotes, approval, changeNotes.getPatchSets().get(newPsId), changeKind);
+    try (Repository repo = repoManager.openRepository(project);
+        RevWalk rw = new RevWalk(repo.newObjectReader())) {
+      return ApprovalContext.create(
+          changeNotes,
+          approval,
+          changeNotes.getPatchSets().get(newPsId),
+          changeKind,
+          rw,
+          repo.getConfig());
+    }
   }
 }
diff --git a/javatests/com/google/gerrit/server/patch/DiffOperationsTest.java b/javatests/com/google/gerrit/server/patch/DiffOperationsTest.java
index 9acb701..8b62628 100644
--- a/javatests/com/google/gerrit/server/patch/DiffOperationsTest.java
+++ b/javatests/com/google/gerrit/server/patch/DiffOperationsTest.java
@@ -19,10 +19,12 @@
 
 import com.google.common.collect.ImmutableMap;
 import com.google.gerrit.common.Nullable;
+import com.google.gerrit.entities.Patch.ChangeType;
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.entities.RefNames;
 import com.google.gerrit.server.git.GitRepositoryManager;
 import com.google.gerrit.server.patch.filediff.FileDiffOutput;
+import com.google.gerrit.server.patch.gitdiff.ModifiedFile;
 import com.google.gerrit.server.util.time.TimeUtil;
 import com.google.gerrit.testing.InMemoryModule;
 import com.google.inject.Guice;
@@ -30,6 +32,7 @@
 import com.google.inject.Injector;
 import java.io.IOException;
 import java.util.Map;
+import java.util.Optional;
 import org.eclipse.jgit.lib.CommitBuilder;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
@@ -37,6 +40,7 @@
 import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.lib.StoredConfig;
 import org.eclipse.jgit.lib.TreeFormatter;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.junit.Before;
@@ -112,6 +116,66 @@
     assertThat(repo.getRefDatabase().exactRef(autoMergeRef)).isNotNull();
   }
 
+  @Test
+  public void loadModifiedFiles() throws Exception {
+    ImmutableMap<String, String> oldFiles =
+        ImmutableMap.of(fileName1, fileContent1, fileName2, fileContent2);
+    ObjectId oldCommitId = createCommit(repo, null, oldFiles);
+
+    ImmutableMap<String, String> newFiles =
+        ImmutableMap.of(fileName1, fileContent1, fileName2, fileContent2 + "\nnew line here");
+    ObjectId newCommitId = createCommit(repo, oldCommitId, newFiles);
+
+    Repository repository = repoManager.openRepository(testProjectName);
+    ObjectReader objectReader = repository.newObjectReader();
+    RevWalk rw = new RevWalk(objectReader);
+    StoredConfig repoConfig = repository.getConfig();
+
+    // This call loads modified files directly without going through the diff cache.
+    Map<String, ModifiedFile> modifiedFiles =
+        diffOperations.loadModifiedFiles(
+            testProjectName, newCommitId, oldCommitId, DiffOptions.DEFAULTS, rw, repoConfig);
+
+    assertThat(modifiedFiles)
+        .containsExactly(
+            fileName2,
+            ModifiedFile.builder()
+                .changeType(ChangeType.MODIFIED)
+                .oldPath(Optional.of(fileName2))
+                .newPath(Optional.of(fileName2))
+                .build());
+  }
+
+  @Test
+  public void loadModifiedFilesAgainstParent() throws Exception {
+    ImmutableMap<String, String> oldFiles =
+        ImmutableMap.of(fileName1, fileContent1, fileName2, fileContent2);
+    ObjectId oldCommitId = createCommit(repo, null, oldFiles);
+
+    ImmutableMap<String, String> newFiles =
+        ImmutableMap.of(fileName1, fileContent1, fileName2, fileContent2 + "\nnew line here");
+    ObjectId newCommitId = createCommit(repo, oldCommitId, newFiles);
+
+    Repository repository = repoManager.openRepository(testProjectName);
+    ObjectReader objectReader = repository.newObjectReader();
+    RevWalk rw = new RevWalk(objectReader);
+    StoredConfig repoConfig = repository.getConfig();
+
+    // This call loads modified files directly without going through the diff cache.
+    Map<String, ModifiedFile> modifiedFiles =
+        diffOperations.loadModifiedFilesAgainstParent(
+            testProjectName, newCommitId, /* parentNum=*/ 0, DiffOptions.DEFAULTS, rw, repoConfig);
+
+    assertThat(modifiedFiles)
+        .containsExactly(
+            fileName2,
+            ModifiedFile.builder()
+                .changeType(ChangeType.MODIFIED)
+                .oldPath(Optional.of(fileName2))
+                .newPath(Optional.of(fileName2))
+                .build());
+  }
+
   private ObjectId createMergeCommit(
       Repository repo,
       ImmutableMap<String, String> fileNameToContent,