Add more commit-attributes to Merge

The new property `Merge.getCommitMeta()` allows specifying more commit
attributes than just the message:
* message
* authors
* author-time
* signed-off-by
* properties

Fixes #5995

api/client/src/main/java/org/projectnessie/client/api/MergeReferenceBuilder.java

@@ -18,6 +18,7 @@
 import javax.validation.constraints.NotBlank;
 import org.projectnessie.error.NessieConflictException;
 import org.projectnessie.error.NessieNotFoundException;
+import org.projectnessie.model.CommitMeta;
 import org.projectnessie.model.MergeResponse;
 import org.projectnessie.model.Reference;
 
@@ -31,14 +32,25 @@ public interface MergeReferenceBuilder extends MergeTransplantBuilder<MergeRefer
   /**
    * Sets a custom merge commit message. The message is auto-generated if not set.
    *
-   * <p>How the auto-generated message is constructed is not specified, but in general it will be
-   * based on the individual messages of the merged commits.
+   * <p>How the auto-generated message is constructed is not specified.
    *
    * @since {@link NessieApiV2}
+   * @see #commitMeta(CommitMeta)
    */
   @Override
   MergeReferenceBuilder message(String message);
 
+  /**
+   * Specify commit properties for the merge-commit, including the commit message, author(s), author
+   * timestamp, signed-off, properties.
+   *
+   * <p>If the given {@link CommitMeta} contains a non-empty message, the message specified via
+   * {@link #message(String)} will be ignored by the server.
+   *
+   * @since {@link NessieApiV2}
+   */
+  MergeReferenceBuilder commitMeta(CommitMeta commitMeta);
+
   MergeReferenceBuilder fromHash(
       @NotBlank @jakarta.validation.constraints.NotBlank String fromHash);
 

api/client/src/main/java/org/projectnessie/client/builder/BaseMergeTransplantBuilder.java

@@ -18,6 +18,7 @@
 import java.util.HashMap;
 import java.util.Map;
 import org.projectnessie.client.api.OnBranchBuilder;
+import org.projectnessie.model.CommitMeta;
 import org.projectnessie.model.ContentKey;
 import org.projectnessie.model.MergeBehavior;
 import org.projectnessie.model.MergeKeyBehavior;
@@ -33,13 +34,20 @@ public abstract class BaseMergeTransplantBuilder<B extends OnBranchBuilder<B>>
   protected MergeBehavior defaultMergeMode;
   protected Map<ContentKey, MergeKeyBehavior> mergeModes;
   protected String message;
+  protected CommitMeta commitMeta;
 
   @SuppressWarnings("unchecked")
   public B message(String message) {
     this.message = message;
     return (B) this;
   }
 
+  @SuppressWarnings("unchecked")
+  public B commitMeta(CommitMeta commitMeta) {
+    this.commitMeta = commitMeta;
+    return (B) this;
+  }
+
   @SuppressWarnings("unchecked")
   public B fromRefName(String fromRefName) {
     this.fromRefName = fromRefName;

api/client/src/main/java/org/projectnessie/client/http/v1api/HttpMergeReference.java

@@ -21,6 +21,7 @@
 import org.projectnessie.client.http.NessieApiClient;
 import org.projectnessie.error.NessieConflictException;
 import org.projectnessie.error.NessieNotFoundException;
+import org.projectnessie.model.CommitMeta;
 import org.projectnessie.model.MergeResponse;
 
 final class HttpMergeReference extends BaseMergeReferenceBuilder {
@@ -36,6 +37,12 @@ public MergeReferenceBuilder message(String message) {
     throw new UnsupportedOperationException("Merge message overrides are not supported in API v1.");
   }
 
+  @Override
+  public MergeReferenceBuilder commitMeta(CommitMeta commitMeta) {
+    throw new UnsupportedOperationException(
+        "Merge commit-meta overrides are not supported in API v1.");
+  }
+
   @Override
   public MergeResponse merge() throws NessieNotFoundException, NessieConflictException {
     ImmutableMerge.Builder merge =

api/client/src/main/java/org/projectnessie/client/http/v2api/HttpMergeReference.java

@@ -46,6 +46,7 @@ public MergeResponse merge() throws NessieNotFoundException, NessieConflictExcep
             .fromHash(fromHash)
             .fromRefName(fromRefName)
             .message(message)
+            .commitMeta(commitMeta)
             .isDryRun(dryRun)
             .isFetchAdditionalInfo(fetchAdditionalInfo)
             .isReturnConflictAsResult(returnConflictAsResult);

api/model/src/main/java/org/projectnessie/api/v2/params/Merge.java

@@ -23,6 +23,8 @@
 import static org.projectnessie.api.v2.doc.ApiDoc.RETURN_CONFLICTS_AS_RESULT_DESCRIPTION;
 import static org.projectnessie.model.Validation.validateHash;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
 import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import javax.annotation.Nullable;
@@ -32,6 +34,7 @@
 import org.eclipse.microprofile.openapi.annotations.media.Schema;
 import org.eclipse.microprofile.openapi.annotations.media.SchemaProperty;
 import org.immutables.value.Value;
+import org.projectnessie.model.CommitMeta;
 import org.projectnessie.model.Validation;
 
 @Schema(
@@ -73,8 +76,18 @@ public interface Merge extends BaseMergeTransplant {
   @jakarta.annotation.Nullable
   @Size
   @jakarta.validation.constraints.Size(min = 1)
+  @Deprecated
   String getMessage();
 
+  /**
+   * Optional: additional merge-commit attributes. If a commit message is specified in this
+   * attribute, {@link #getMessage()} will be ignored.
+   */
+  @Nullable
+  @jakarta.annotation.Nullable
+  @JsonInclude(Include.NON_NULL)
+  CommitMeta getCommitMeta();
+
   @NotBlank
   @jakarta.validation.constraints.NotBlank
   @Pattern(regexp = Validation.HASH_REGEX, message = Validation.HASH_MESSAGE)

servers/jax-rs-tests/src/main/java/org/projectnessie/jaxrs/tests/BaseTestNessieApi.java

@@ -20,6 +20,7 @@
 import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
+import static java.util.Collections.singletonMap;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.assertj.core.api.InstanceOfAssertFactories.list;
@@ -30,6 +31,7 @@
 
 import com.google.common.collect.ImmutableMap;
 import com.google.common.hash.Hashing;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
@@ -475,9 +477,48 @@ public void commitMergeTransplant() throws Exception {
         .extracting(EntriesResponse.Entry::getName)
         .containsExactly(ContentKey.of("a"), ContentKey.of("b"));
 
-    api().mergeRefIntoBranch().fromRef(branch).branch(main).keepIndividualCommits(false).merge();
-    Reference main2 = api().getReference().refName(main.getName()).get();
-    soft.assertThat(api().getCommitLog().refName(main.getName()).get().getLogEntries()).hasSize(3);
+    Reference main2;
+    if (isV2()) {
+      api()
+          .mergeRefIntoBranch()
+          .fromRef(branch)
+          .branch(main)
+          .message("not the merge message")
+          .commitMeta(
+              CommitMeta.builder()
+                  .message("My custom merge message")
+                  .author("NessieHerself")
+                  .signedOffBy("Arctic")
+                  .authorTime(Instant.EPOCH)
+                  .putProperties("property", "value")
+                  .build())
+          .keepIndividualCommits(false)
+          .merge();
+      main2 = api().getReference().refName(main.getName()).get();
+      List<LogEntry> postMergeLog =
+          api().getCommitLog().refName(main.getName()).get().getLogEntries();
+      soft.assertThat(postMergeLog)
+          .hasSize(3)
+          .first()
+          .extracting(LogEntry::getCommitMeta)
+          .extracting(
+              CommitMeta::getMessage,
+              CommitMeta::getAllAuthors,
+              CommitMeta::getAllSignedOffBy,
+              CommitMeta::getAuthorTime,
+              CommitMeta::getProperties)
+          .containsExactly(
+              "My custom merge message",
+              singletonList("NessieHerself"),
+              singletonList("Arctic"),
+              Instant.EPOCH,
+              ImmutableMap.of("property", "value", "_merge_parent", branch.getHash()));
+    } else {
+      api().mergeRefIntoBranch().fromRef(branch).branch(main).keepIndividualCommits(false).merge();
+      main2 = api().getReference().refName(main.getName()).get();
+      soft.assertThat(api().getCommitLog().refName(main.getName()).get().getLogEntries())
+          .hasSize(3);
+    }
 
     soft.assertThat(api().getEntries().reference(main2).get().getEntries())
         .extracting(EntriesResponse.Entry::getName)

servers/rest-services/src/main/java/org/projectnessie/services/rest/RestTreeResource.java

@@ -31,6 +31,7 @@
 import org.projectnessie.error.NessieConflictException;
 import org.projectnessie.error.NessieNotFoundException;
 import org.projectnessie.model.Branch;
+import org.projectnessie.model.CommitMeta;
 import org.projectnessie.model.EntriesResponse;
 import org.projectnessie.model.ImmutableEntriesResponse;
 import org.projectnessie.model.ImmutableLogResponse;
@@ -219,7 +220,7 @@ public MergeResponse transplantCommitsIntoBranch(
         .transplantCommitsIntoBranch(
             branchName,
             expectedHash,
-            message,
+            message != null ? CommitMeta.fromMessage(message) : null,
             transplant.getHashesToTransplant(),
             transplant.getFromRefName(),
             transplant.keepIndividualCommits(),

servers/rest-services/src/main/java/org/projectnessie/services/rest/RestV2TreeResource.java

@@ -15,6 +15,7 @@
  */
 package org.projectnessie.services.rest;
 
+import static java.util.Collections.emptyList;
 import static org.projectnessie.api.v2.params.ReferenceResolver.resolveReferencePathElement;
 import static org.projectnessie.api.v2.params.ReferenceResolver.resolveReferencePathElementWithDefaultBranch;
 import static org.projectnessie.services.impl.RefUtil.toReference;
@@ -35,6 +36,7 @@
 import org.projectnessie.api.v2.params.Transplant;
 import org.projectnessie.error.NessieConflictException;
 import org.projectnessie.error.NessieNotFoundException;
+import org.projectnessie.model.CommitMeta;
 import org.projectnessie.model.CommitResponse;
 import org.projectnessie.model.ContentKey;
 import org.projectnessie.model.ContentResponse;
@@ -43,6 +45,7 @@
 import org.projectnessie.model.EntriesResponse;
 import org.projectnessie.model.GetMultipleContentsRequest;
 import org.projectnessie.model.GetMultipleContentsResponse;
+import org.projectnessie.model.ImmutableCommitMeta;
 import org.projectnessie.model.ImmutableDiffResponse;
 import org.projectnessie.model.ImmutableEntriesResponse;
 import org.projectnessie.model.ImmutableGetMultipleContentsRequest;
@@ -320,11 +323,15 @@ public GetMultipleContentsResponse getMultipleContents(
   public MergeResponse transplantCommitsIntoBranch(String branch, Transplant transplant)
       throws NessieNotFoundException, NessieConflictException {
     ParsedReference ref = resolveRef(branch);
+
+    String msg = transplant.getMessage();
+    CommitMeta meta = CommitMeta.builder().message(msg == null ? "" : msg).build();
+
     return tree()
         .transplantCommitsIntoBranch(
             ref.name(),
             ref.hash(),
-            transplant.getMessage(),
+            meta,
             transplant.getHashesToTransplant(),
             transplant.getFromRefName(),
             true,
@@ -340,14 +347,28 @@ public MergeResponse transplantCommitsIntoBranch(String branch, Transplant trans
   public MergeResponse mergeRefIntoBranch(String branch, Merge merge)
       throws NessieNotFoundException, NessieConflictException {
     ParsedReference ref = resolveRef(branch);
+
+    String msg = merge.getMessage();
+
+    ImmutableCommitMeta.Builder meta = CommitMeta.builder();
+    CommitMeta commitMeta = merge.getCommitMeta();
+    if (commitMeta != null) {
+      meta.from(commitMeta).committer(null).commitTime(null).parentCommitHashes(emptyList());
+      if (commitMeta.getMessage().isEmpty() && msg != null) {
+        meta.message(msg);
+      }
+    } else {
+      meta.message(msg == null ? "" : msg);
+    }
+
     return tree()
         .mergeRefIntoBranch(
             ref.name(),
             ref.hash(),
             merge.getFromRefName(),
             merge.getFromHash(),
             false,
-            merge.getMessage(),
+            meta.build(),
             merge.getKeyMergeModes(),
             merge.getDefaultKeyMergeMode(),
             merge.isDryRun(),