Ensure that match_only_text and wildcard fields can be added to defau…

…lt_field list (#29634)

Fixes the construction of the index template's default_field list so that fields of type match_only_text
and wildcard can be added to it.

CHANGELOG.next.asciidoc

@@ -78,6 +78,8 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 
 *Affecting all Beats*
 
+- Fields of type `match_only_text` (i.e. `message`) and `wildcard` were missing from the template's default_field list. {issue}29633[29633] {pull}29634[29634]
+
 *Auditbeat*
 
 

libbeat/template/processor.go

@@ -136,7 +136,7 @@ func (p *Processor) Process(fields mapping.Fields, state *fieldState, output, an
 
 		if *field.DefaultField {
 			switch field.Type {
-			case "", "keyword", "text":
+			case "", "keyword", "text", "match_only_text", "wildcard":
 				addToDefaultFields(&field)
 			}
 		}

libbeat/template/processor_test.go

@@ -719,6 +719,18 @@ func TestProcessDefaultField(t *testing.T) {
 				},
 			},
 		},
+		// Ensure that text_only_keyword fields can be added to default_field
+		mapping.Field{
+			Name:         "a_match_only_text_field",
+			Type:         "match_only_text",
+			DefaultField: &enableDefaultField,
+		},
+		// Ensure that wildcard fields can be added to default_field
+		mapping.Field{
+			Name:         "a_wildcard_field",
+			Type:         "wildcard",
+			DefaultField: &enableDefaultField,
+		},
 	}
 
 	version, err := common.NewVersion("7.0.0")
@@ -734,6 +746,8 @@ func TestProcessDefaultField(t *testing.T) {
 	}
 
 	expectedFields := []string{
+		"a_match_only_text_field",
+		"a_wildcard_field",
 		"bar",
 		"nested.bar",
 		"nested.foo",