Let users know which change prevents submit in case of MISSING_DEPENDENCY

If a change cannot be submitted because it depends on a commit that
cannot be merged the user got the following message:

  Depends on change that was not submitted. Commit <commit> depends on
  commit <other-commit> which cannot be merged.

To find the change to which <other-commit> belongs the user must do a
change query. Do this for the user and return the change ID too.

Now we return:

  Depends on change that was not submitted. Commit <commit> depends on
  commit <other-commit> of change <other-change> which cannot be merged.

Returning the commit SHA1 of <other-commit> is still useful since the
commit that prevents submit may be an outdated patch set and this can be
found easier if the commit SHA1 is known.

Change-Id: I1368af204702a06d01ee6f812a5da5ac419b89d7
Signed-off-by: Edwin Kempin <ekempin@google.com>

java/com/google/gerrit/server/git/MergeUtil.java

@@ -216,7 +216,7 @@ public class MergeUtil {
     List<CodeReviewCommit> result = new ArrayList<>();
     try {
       result.addAll(mergeSorter.sort(toSort));
-    } catch (IOException e) {
+    } catch (IOException | OrmException e) {
       throw new IntegrationException("Branch head sorting failed", e);
     }
     result.sort(CodeReviewCommit.ORDER);
@@ -566,7 +566,7 @@ public class MergeUtil {
       throws IntegrationException {
     try {
       return !mergeSorter.sort(Collections.singleton(toMerge)).contains(toMerge);
-    } catch (IOException e) {
+    } catch (IOException | OrmException e) {
       throw new IntegrationException("Branch head sorting failed", e);
     }
   }

java/com/google/gerrit/server/submit/CommitMergeStatus.java

@@ -14,6 +14,14 @@
 
 package com.google.gerrit.server.submit;
 
+import static java.util.stream.Collectors.toSet;
+
+import com.google.gerrit.server.query.change.ChangeData;
+import com.google.gerrit.server.query.change.InternalChangeQuery;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Provider;
+import java.util.List;
+
 /**
  * Status codes set on {@link com.google.gerrit.server.git.CodeReviewCommit}s by {@link
  * SubmitStrategy} implementations.
@@ -76,4 +84,23 @@ public enum CommitMergeStatus {
   public String getDescription() {
     return description;
   }
+
+  public static String createMissingDependencyMessage(
+      Provider<InternalChangeQuery> queryProvider, String commit, String otherCommit)
+      throws OrmException {
+    List<ChangeData> changes = queryProvider.get().enforceVisibility(true).byCommit(otherCommit);
+
+    if (changes.isEmpty()) {
+      return String.format(
+          "Commit %s depends on commit %s which cannot be merged.", commit, otherCommit);
+    } else if (changes.size() == 1) {
+      return String.format(
+          "Commit %s depends on commit %s of change %d which cannot be merged.",
+          commit, otherCommit, changes.get(0).getId().get());
+    } else {
+      return String.format(
+          "Commit %s depends on commit %s of changes %s which cannot be merged.",
+          commit, otherCommit, changes.stream().map(cd -> cd.getId().get()).collect(toSet()));
+    }
+  }
 }

java/com/google/gerrit/server/submit/MergeSorter.java

@@ -16,6 +16,9 @@ package com.google.gerrit.server.submit;
 
 import com.google.gerrit.server.git.CodeReviewCommit;
 import com.google.gerrit.server.git.CodeReviewCommit.CodeReviewRevWalk;
+import com.google.gerrit.server.query.change.InternalChangeQuery;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Provider;
 import java.io.IOException;
 import java.util.Collection;
 import java.util.HashSet;
@@ -29,21 +32,24 @@ public class MergeSorter {
   private final CodeReviewRevWalk rw;
   private final RevFlag canMergeFlag;
   private final Set<RevCommit> accepted;
+  private final Provider<InternalChangeQuery> queryProvider;
   private final Set<CodeReviewCommit> incoming;
 
   public MergeSorter(
       CodeReviewRevWalk rw,
       Set<RevCommit> alreadyAccepted,
       RevFlag canMergeFlag,
+      Provider<InternalChangeQuery> queryProvider,
       Set<CodeReviewCommit> incoming) {
     this.rw = rw;
     this.canMergeFlag = canMergeFlag;
     this.accepted = alreadyAccepted;
+    this.queryProvider = queryProvider;
     this.incoming = incoming;
   }
 
   public Collection<CodeReviewCommit> sort(Collection<CodeReviewCommit> toMerge)
-      throws IOException {
+      throws IOException, OrmException {
     final Set<CodeReviewCommit> heads = new HashSet<>();
     final Set<CodeReviewCommit> sort = new HashSet<>(toMerge);
     while (!sort.isEmpty()) {
@@ -64,8 +70,7 @@ public class MergeSorter {
           //
           n.setStatusCode(CommitMergeStatus.MISSING_DEPENDENCY);
           n.setStatusMessage(
-              String.format(
+              CommitMergeStatus.createMissingDependencyMessage(queryProvider, n.name(), c.name()));
-                  "Commit %s depends on commit %s which cannot be merged.", n.name(), c.name()));
           break;
         }
         contents.add(c);

java/com/google/gerrit/server/submit/RebaseSorter.java

@@ -59,7 +59,8 @@ public class RebaseSorter {
     this.incoming = incoming;
   }
 
-  public List<CodeReviewCommit> sort(Collection<CodeReviewCommit> toSort) throws IOException {
+  public List<CodeReviewCommit> sort(Collection<CodeReviewCommit> toSort)
+      throws IOException, OrmException {
     final List<CodeReviewCommit> sorted = new ArrayList<>();
     final Set<CodeReviewCommit> sort = new HashSet<>(toSort);
     while (!sort.isEmpty()) {
@@ -83,8 +84,8 @@ public class RebaseSorter {
             //
             n.setStatusCode(CommitMergeStatus.MISSING_DEPENDENCY);
             n.setStatusMessage(
-                String.format(
+                CommitMergeStatus.createMissingDependencyMessage(
-                    "Commit %s depends on commit %s which cannot be merged.", n.name(), c.name()));
+                    queryProvider, n.name(), c.name()));
           }
           // Stop RevWalk because c is either a merged commit or a missing
           // dependency. Not need to walk further.

java/com/google/gerrit/server/submit/RebaseSubmitStrategy.java

@@ -59,7 +59,7 @@ public class RebaseSubmitStrategy extends SubmitStrategy {
     List<CodeReviewCommit> sorted;
     try {
       sorted = args.rebaseSorter.sort(toMerge);
-    } catch (IOException e) {
+    } catch (IOException | OrmException e) {
       throw new IntegrationException("Commit sorting failed", e);
     }
     List<SubmitStrategyOp> ops = new ArrayList<>(sorted.size());

java/com/google/gerrit/server/submit/SubmitDryRun.java

@@ -27,7 +27,9 @@ import com.google.gerrit.server.git.MergeUtil;
 import com.google.gerrit.server.project.NoSuchProjectException;
 import com.google.gerrit.server.project.ProjectCache;
 import com.google.gerrit.server.project.ProjectState;
+import com.google.gerrit.server.query.change.InternalChangeQuery;
 import com.google.inject.Inject;
+import com.google.inject.Provider;
 import java.io.IOException;
 import java.util.Collection;
 import java.util.HashSet;
@@ -91,11 +93,16 @@ public class SubmitDryRun {
 
   private final ProjectCache projectCache;
   private final MergeUtil.Factory mergeUtilFactory;
+  private final Provider<InternalChangeQuery> queryProvider;
 
   @Inject
-  SubmitDryRun(ProjectCache projectCache, MergeUtil.Factory mergeUtilFactory) {
+  SubmitDryRun(
+      ProjectCache projectCache,
+      MergeUtil.Factory mergeUtilFactory,
+      Provider<InternalChangeQuery> queryProvider) {
     this.projectCache = projectCache;
     this.mergeUtilFactory = mergeUtilFactory;
+    this.queryProvider = queryProvider;
   }
 
   public boolean run(
@@ -116,7 +123,8 @@ public class SubmitDryRun {
             repo,
             rw,
             mergeUtilFactory.create(getProject(destBranch)),
-            new MergeSorter(rw, alreadyAccepted, canMerge, ImmutableSet.of(toMergeCommit)));
+            new MergeSorter(
+                rw, alreadyAccepted, canMerge, queryProvider, ImmutableSet.of(toMergeCommit)));
 
     switch (submitType) {
       case CHERRY_PICK:

java/com/google/gerrit/server/submit/SubmitStrategy.java

@@ -204,7 +204,8 @@ public abstract class SubmitStrategy {
               projectCache.get(destBranch.getParentKey()),
               "project not found: %s",
               destBranch.getParentKey());
-      this.mergeSorter = new MergeSorter(rw, alreadyAccepted, canMergeFlag, incoming);
+      this.mergeSorter =
+          new MergeSorter(rw, alreadyAccepted, canMergeFlag, queryProvider, incoming);
       this.rebaseSorter =
           new RebaseSorter(
               rw, mergeTip.getInitialTip(), alreadyAccepted, canMergeFlag, queryProvider, incoming);

javatests/com/google/gerrit/acceptance/rest/change/SubmitByMergeIfNecessaryIT.java

@@ -408,6 +408,8 @@ public class SubmitByMergeIfNecessaryIT extends AbstractSubmitByMerge {
             + change3a.getCommit().name()
             + " depends on commit "
             + change2.getCommit().name()
+            + " of change "
+            + change2.getChange().getId()
             + " which cannot be merged.");
 
     RevCommit tipbranch = getRemoteLog(project, "branch").get(0);
@@ -511,6 +513,8 @@ public class SubmitByMergeIfNecessaryIT extends AbstractSubmitByMerge {
             + change3.getCommit().name()
             + " depends on commit "
             + change2result.getCommit().name()
+            + " of change "
+            + change2result.getChange().getId()
             + " which cannot be merged.");
 
     assertRefUpdatedEvents();