File filter tweaks.

file.go

@@ -157,12 +157,14 @@ func (f FileFilters) types() []string {
 				res = append(res, pattern)
 				continue
 			}
-
-			ext := pattern[strings.LastIndexByte(pattern, '.')+1:]
+			dot := strings.LastIndexByte(pattern, '.')
+			if dot < 0 {
+				continue
+			}
 
 			var escape bool
 			var buf strings.Builder
-			for _, b := range []byte(removeClasses(ext)) {
+			for _, b := range []byte(removeClasses(pattern[dot+1:])) {
 				switch {
 				case escape:
 					escape = false
@@ -174,9 +176,7 @@ func (f FileFilters) types() []string {
 				}
 				buf.WriteByte(b)
 			}
-			if buf.Len() > 0 {
-				res = append(res, buf.String())
-			}
+			res = append(res, buf.String())
 		}
 	}
 	if res == nil {

file_filter_test.go

@@ -31,6 +31,7 @@ func TestFileFilters_simplify(t *testing.T) {
 	}{
 		{[]string{``}, nil},
 		{[]string{`*.\?`}, nil},
+		{[]string{`*.`}, []string{`*.`}},
 		{[]string{`*.png`}, []string{"*.png"}},
 		{[]string{`*.pn?`}, []string{"*.pn?"}},
 		{[]string{`*.pn;`}, []string{"*.pn?"}},
@@ -91,6 +92,7 @@ func TestFileFilters_types(t *testing.T) {
 		want []string
 	}{
 		{[]string{``}, nil},
+		{[]string{`*.`}, []string{".", ""}},
 		{[]string{`*.png`}, []string{".", "png"}},
 		{[]string{`*.pn?`}, nil},
 		{[]string{`*.pn;`}, []string{".", "pn;"}},