Set document on script when using Bytes.WithScript (#43390)

Long and Double ValuesSource set the current document on the script
before executing, but Bytes was missing this method call.  That meant
it was possible to generate an OutOfBoundsException when using
a "value" script (field + script) on keyword or other bytes
fields.

This adds in the method call, and a few yaml tests to verify correct
behavior.

modules/lang-painless/src/test/resources/rest-api-spec/test/painless/100_terms_agg.yml

@@ -0,0 +1,104 @@
+setup:
+  - do:
+      indices.create:
+          index: test_1
+          body:
+            settings:
+              number_of_replicas: 0
+            mappings:
+              properties:
+                str:
+                   type: keyword
+                double:
+                  type: double
+                number:
+                  type: long
+
+  - do:
+      cluster.health:
+        wait_for_status: green
+
+  - do:
+      index:
+        index: test_1
+        id: 1
+        body:
+          str: "abc"
+          double: 1.0
+          number: 1
+
+  - do:
+      index:
+        index: test_1
+        id: 2
+        body:
+          str: "abc"
+          double: 1.0
+          number: 1
+
+  - do:
+      index:
+        index: test_1
+        id: 3
+        body:
+          str: "bcd"
+          double: 2.0
+          number: 2
+
+  - do:
+      indices.refresh: {}
+
+---
+"String Value Script with doc notation":
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body: { "size" : 0, "aggs" : { "str_terms" : { "terms" : { "field" : "str", "script": { "source": "return doc.str[0] + \"1\""} } } } }
+
+  - match: { hits.total: 3 }
+
+  - length: { aggregations.str_terms.buckets: 2 }
+  - match: { aggregations.str_terms.buckets.0.key: "abc1" }
+  - is_false: aggregations.str_terms.buckets.0.key_as_string
+  - match: { aggregations.str_terms.buckets.0.doc_count: 2 }
+  - match: { aggregations.str_terms.buckets.1.key: "bcd1" }
+  - is_false: aggregations.str_terms.buckets.1.key_as_string
+  - match: { aggregations.str_terms.buckets.1.doc_count: 1 }
+
+---
+"Long Value Script with doc notation":
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body: { "size" : 0, "aggs" : { "long_terms" : { "terms" : { "field" : "number", "script": { "source": "return doc.number[0] + 1"} } } } }
+
+  - match: { hits.total: 3 }
+
+  - length: { aggregations.long_terms.buckets: 2 }
+  - match: { aggregations.long_terms.buckets.0.key: 2.0 }
+  - is_false: aggregations.long_terms.buckets.0.key_as_string
+  - match: { aggregations.long_terms.buckets.0.doc_count: 2 }
+  - match: { aggregations.long_terms.buckets.1.key: 3.0 }
+  - is_false: aggregations.long_terms.buckets.1.key_as_string
+  - match: { aggregations.long_terms.buckets.1.doc_count: 1 }
+
+---
+"Double Value Script with doc notation":
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body: { "size" : 0, "aggs" : { "double_terms" : { "terms" : { "field" : "double", "script": { "source": "return doc.double[0] + 1"} } } } }
+
+  - match: { hits.total: 3 }
+
+  - length: { aggregations.double_terms.buckets: 2 }
+  - match: { aggregations.double_terms.buckets.0.key: 2.0 }
+  - is_false: aggregations.double_terms.buckets.0.key_as_string
+  - match: { aggregations.double_terms.buckets.0.doc_count: 2 }
+  - match: { aggregations.double_terms.buckets.1.key: 3.0 }
+  - is_false: aggregations.double_terms.buckets.1.key_as_string
+  - match: { aggregations.double_terms.buckets.1.doc_count: 1 }
+

server/src/main/java/org/elasticsearch/search/aggregations/support/ValuesSource.java

@@ -452,6 +452,7 @@ public abstract class ValuesSource {
                 if (bytesValues.advanceExact(doc)) {
                     count = bytesValues.docValueCount();
                     grow();
+                    script.setDocument(doc);
                     for (int i = 0; i < count; ++i) {
                         final BytesRef value = bytesValues.nextValue();
                         script.setNextAggregationValue(value.utf8ToString());