fix(version-ls): clamp --limit to slice length to avoid panic (#1662)

cmd/root.go

@@ -380,7 +380,7 @@ func NewCmdVersionLs() *cobra.Command {
 				})
 			}
 
-			if flags.limit > 0 {
+			if flags.limit > 0 && flags.limit < len(filteredTags) {
 				filteredTags = filteredTags[0:flags.limit]
 			}
 			fmt.Println(strings.Join(filteredTags, "\n"))

cmd/root_test.go

@@ -0,0 +1,39 @@
+/*
+Copyright © 2020-2023 The k3d Author(s)
+*/
+package cmd
+
+import "testing"
+
+// Test_VersionLs_LimitClamp_Regression_1662 verifies that the slice expression
+// used to apply the `--limit` flag in `k3d version list` does not panic when
+// the limit exceeds the number of filtered tags. See issue #1662 where
+// `k3d version list -i '^1\.333' -l 1 -o repo k3s` panicked with
+// "slice bounds out of range [:1] with capacity 0".
+func Test_VersionLs_LimitClamp_Regression_1662(t *testing.T) {
+	tests := []struct {
+		name     string
+		tags     []string
+		limit    int
+		expected int
+	}{
+		{name: "limit zero leaves slice untouched", tags: []string{"a", "b"}, limit: 0, expected: 2},
+		{name: "limit smaller than length clamps", tags: []string{"a", "b", "c"}, limit: 2, expected: 2},
+		{name: "limit equal to length is a no-op", tags: []string{"a", "b"}, limit: 2, expected: 2},
+		{name: "limit larger than length must not panic", tags: []string{"a"}, limit: 5, expected: 1},
+		{name: "limit larger than empty slice must not panic", tags: []string{}, limit: 1, expected: 0},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			filteredTags := tt.tags
+			// Mirror the production expression from NewCmdVersionLs.
+			if tt.limit > 0 && tt.limit < len(filteredTags) {
+				filteredTags = filteredTags[0:tt.limit]
+			}
+			if got := len(filteredTags); got != tt.expected {
+				t.Fatalf("len(filteredTags) = %d, want %d", got, tt.expected)
+			}
+		})
+	}
+}