Merge changes If23916d2,I70110e99 into stable-2.16

* changes:
  Schema: Show only a single log for inexistent commits
  Schema: Refactor lambda in buildFields to a separate function

java/com/google/gerrit/index/Schema.java

@@ -15,11 +15,9 @@
 package com.google.gerrit.index;
 
 import static com.google.common.base.Preconditions.checkState;
+import static com.google.common.collect.ImmutableList.toImmutableList;
 
-import com.google.common.base.Function;
 import com.google.common.base.MoreObjects;
-import com.google.common.base.Predicates;
-import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.flogger.FluentLogger;
@@ -28,6 +26,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Objects;
 import java.util.Optional;
 
 /** Specific version of a secondary index schema. */
@@ -165,26 +164,19 @@ public class Schema<T> {
     return true;
   }
 
-  /**
-   * Build all fields in the schema from an input object.
-   *
-   * <p>Null values are omitted, as are fields which cause errors, which are logged.
-   *
-   * @param obj input object.
-   * @return all non-null field values from the object.
-   */
-  public final Iterable<Values<T>> buildFields(T obj) {
-    return FluentIterable.from(fields.values())
-        .transform(
-            new Function<FieldDef<T, ?>, Values<T>>() {
-              @Override
-              public Values<T> apply(FieldDef<T, ?> f) {
+  private Values<T> fieldValues(T obj, FieldDef<T, ?> f) {
     Object v;
     try {
       v = f.get(obj);
     } catch (OrmException e) {
-                  logger.atSevere().withCause(e).log(
-                      "error getting field %s of %s", f.getName(), obj);
+      // OrmException is thrown when the object is not found. On this case,
+      // it is pointless to make further attempts for each field, so propagate
+      // the exception to return an empty list.
+      logger.atSevere().withCause(e).log("error getting field %s of %s", f.getName(), obj);
+      throw new RuntimeException(
+          e); // work around throwing checked exceptions from methods used in Streams
+    } catch (RuntimeException e) {
+      logger.atSevere().withCause(e).log("error getting field %s of %s", f.getName(), obj);
       return null;
     }
     if (v == null) {
@@ -195,8 +187,27 @@ public class Schema<T> {
       return new Values<>(f, Collections.singleton(v));
     }
   }
-            })
-        .filter(Predicates.notNull());
+
+  /**
+   * Build all fields in the schema from an input object.
+   *
+   * <p>Null values are omitted, as are fields which cause errors, which are logged.
+   *
+   * @param obj input object.
+   * @return all non-null field values from the object.
+   */
+  public final Iterable<Values<T>> buildFields(T obj) {
+    try {
+      return fields.values().stream()
+          .map(f -> fieldValues(obj, f))
+          .filter(Objects::nonNull)
+          .collect(toImmutableList());
+    } catch (RuntimeException e) {
+      if (e.getCause().getClass().equals(OrmException.class)) {
+        return ImmutableList.of();
+      }
+      throw e;
+    }
   }
 
   @Override