fix(helm): Don't crash in search if upper case chars are encountered.

Closes #3088

(cherry picked from commit d8489901)

cmd/helm/search/search.go

@@ -146,11 +146,11 @@ func (i *Index) SearchLiteral(term string, threshold int) []*Result {
 	term = strings.ToLower(term)
 	buf := []*Result{}
 	for k, v := range i.lines {
-		k = strings.ToLower(k)
-		v = strings.ToLower(v)
-		res := strings.Index(v, term)
-		if score := i.calcScore(res, v); res != -1 && score < threshold {
-			parts := strings.Split(k, verSep) // Remove version, if it is there.
+		lk := strings.ToLower(k)
+		lv := strings.ToLower(v)
+		res := strings.Index(lv, term)
+		if score := i.calcScore(res, lv); res != -1 && score < threshold {
+			parts := strings.Split(lk, verSep) // Remove version, if it is there.
 			buf = append(buf, &Result{Name: parts[0], Score: score, Chart: i.charts[k]})
 		}
 	}

cmd/helm/search/search_test.go

@@ -91,10 +91,10 @@ var indexfileEntries = map[string]repo.ChartVersions{
 			},
 		},
 		{
-			URLs: []string{"http://example.com/charts/santa-maria-1.2.2.tgz"},
+			URLs: []string{"http://example.com/charts/santa-maria-1.2.2-rc-1.tgz"},
 			Metadata: &chart.Metadata{
 				Name:        "santa-maria",
-				Version:     "1.2.2",
+				Version:     "1.2.2-RC-1",
 				Description: "Three boat",
 			},
 		},