internal/history: catch empty non-nil fix summaries in TestReleases

When there are no security fixes (or no bug fixes) in a given release,
it's represented with a nil *FixSummary. Since it also may reasonably
be represented with an empty FixSummary, add a test to enforce one of
the two possible styles is consistently chosen. The template handles
an empty non-nil *FixSummary as a very generic "there were some fixes"
text, which is never what we want.

Change-Id: I96ac7cdf37ec7a8406f31500024150df422730bb
Reviewed-on: https://go-review.googlesource.com/c/website/+/603495
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

internal/history/release_test.go

@@ -38,11 +38,17 @@ func TestReleases(t *testing.T) {
 		}
 		lastMinor[major] = r.Version.Z
 		if r.Security != nil {
+			if s := r.Security; s.Quantifier == "" && len(s.Components) == 0 && len(s.Packages) == 0 {
+				t.Errorf("version %v security fix summary is included (non-nil) but summarizes zero security fixes", r.Version)
+			}
 			if p := r.Security.Packages; !sort.StringsAreSorted(p) {
 				t.Errorf("version %v security fix packages out of order: %v vs %v", r.Version, p, sorted(p))
 			}
 		}
 		if r.Bug != nil {
+			if b := r.Bug; b.Quantifier == "" && len(b.Components) == 0 && len(b.Packages) == 0 {
+				t.Errorf("version %v bug fix summary is included (non-nil) but summarizes zero bug fixes", r.Version)
+			}
 			if p := r.Bug.Packages; !sort.StringsAreSorted(p) {
 				t.Errorf("version %v bug fix packages out of order: %v vs %v", r.Version, p, sorted(p))
 			}