Merge "GetDiff: Reject edit as base as ‘400 Bad Request’"

java/com/google/gerrit/server/restapi/change/GetDiff.java

@@ -29,6 +29,7 @@ import com.google.gerrit.extensions.common.DiffInfo;
 import com.google.gerrit.extensions.common.DiffWebLinkInfo;
 import com.google.gerrit.extensions.common.WebLinkInfo;
 import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.CacheControl;
 import com.google.gerrit.extensions.restapi.IdString;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
@@ -102,8 +103,8 @@ public class GetDiff implements RestReadView<FileResource> {
 
   @Override
   public Response<DiffInfo> apply(FileResource resource)
-      throws ResourceConflictException, ResourceNotFoundException, AuthException,
-          InvalidChangeOperationException, IOException, PermissionBackendException {
+      throws BadRequestException, ResourceConflictException, ResourceNotFoundException,
+          AuthException, InvalidChangeOperationException, IOException, PermissionBackendException {
     DiffPreferencesInfo prefs = new DiffPreferencesInfo();
     if (whitespace != null) {
       prefs.ignoreWhitespace = whitespace;
@@ -130,6 +131,9 @@ public class GetDiff implements RestReadView<FileResource> {
       RevisionResource baseResource =
           revisions.parse(resource.getRevision().getChangeResource(), IdString.fromDecoded(base));
       basePatchSet = baseResource.getPatchSet();
+      if (basePatchSet.id().get() == 0) {
+        throw new BadRequestException("edit not allowed as base");
+      }
       psf = patchScriptFactoryFactory.create(notes, fileName, basePatchSet.id(), pId, prefs);
     } else if (parentNum > 0) {
       psf = patchScriptFactoryFactory.create(notes, fileName, parentNum - 1, pId, prefs);

javatests/com/google/gerrit/acceptance/api/revision/RevisionDiffIT.java

@@ -21,6 +21,7 @@ import static com.google.gerrit.entities.Patch.MERGE_LIST;
 import static com.google.gerrit.extensions.common.testing.DiffInfoSubject.assertThat;
 import static com.google.gerrit.extensions.common.testing.FileInfoSubject.assertThat;
 import static com.google.gerrit.git.ObjectIds.abbreviateName;
+import static com.google.gerrit.testing.GerritJUnit.assertThrows;
 import static java.util.stream.Collectors.joining;
 import static java.util.stream.Collectors.toMap;
 
@@ -41,6 +42,7 @@ import com.google.gerrit.extensions.client.DiffPreferencesInfo;
 import com.google.gerrit.extensions.common.ChangeType;
 import com.google.gerrit.extensions.common.DiffInfo;
 import com.google.gerrit.extensions.common.FileInfo;
+import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.BinaryResult;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.testing.ConfigSuite;
@@ -2718,6 +2720,23 @@ public class RevisionDiffIT extends AbstractDaemonTest {
     assertThat(diffInfo).content().element(0).numberOfSkippedLines().isGreaterThan(0);
   }
 
+  @Test
+  public void editNotAllowedAsBase() throws Exception {
+    gApi.changes().id(changeId).edit().create();
+
+    BadRequestException e =
+        assertThrows(
+            BadRequestException.class,
+            () -> getDiffRequest(changeId, CURRENT, FILE_NAME).withBase("edit").get());
+    assertThat(e).hasMessageThat().isEqualTo("edit not allowed as base");
+
+    e =
+        assertThrows(
+            BadRequestException.class,
+            () -> getDiffRequest(changeId, CURRENT, FILE_NAME).withBase("0").get());
+    assertThat(e).hasMessageThat().isEqualTo("edit not allowed as base");
+  }
+
   private static CommentInput createCommentInput(
       int startLine, int startCharacter, int endLine, int endCharacter, String message) {
     CommentInput comment = new CommentInput();