search request JSON omitting size, now defaults to 10

this change only affects JSON parsing, any search request which
omits the size field entirely now defaults to 10 which
is the same behavior as NewSearchRequest()

0 is still a valid size, but must be set explicitly

search.go

@@ -182,7 +182,7 @@ func (r *SearchRequest) AddFacet(facetName string, f *FacetRequest) {
 func (r *SearchRequest) UnmarshalJSON(input []byte) error {
 	var temp struct {
 		Q         json.RawMessage   `json:"query"`
-		Size      int               `json:"size"`
+		Size      *int              `json:"size"`
 		From      int               `json:"from"`
 		Highlight *HighlightRequest `json:"highlight"`
 		Fields    []string          `json:"fields"`
@@ -195,7 +195,11 @@ func (r *SearchRequest) UnmarshalJSON(input []byte) error {
 		return err
 	}
 
-	r.Size = temp.Size
+	if temp.Size == nil {
+		r.Size = 10
+	} else {
+		r.Size = *temp.Size
+	}
 	r.From = temp.From
 	r.Explain = temp.Explain
 	r.Highlight = temp.Highlight