fix: parse the uri correctly when it contains a port

go/shim/main.go

@@ -222,7 +222,17 @@ func loadChartFromOCI(chartRef string, version string, registryClient *registry.
 
 	// Build the full reference with version tag
 	ref := strings.TrimPrefix(chartRef, fmt.Sprintf("%s://", registry.OCIScheme))
-	if version != "" && !strings.Contains(ref, ":") {
+
+	// Check if the chart name (after the last /) already has a version tag
+	// We need to check only the chart name part, not the whole ref, because
+	// the registry URL may contain a port number (e.g., localhost:5001/chart)
+	// which would incorrectly match a simple Contains(ref, ":") check
+	lastSlash := strings.LastIndex(ref, "/")
+	chartName := ref
+	if lastSlash >= 0 {
+		chartName = ref[lastSlash+1:]
+	}
+	if version != "" && !strings.Contains(chartName, ":") {
 		ref = fmt.Sprintf("%s:%s", ref, version)
 	}
 

go/shim/oci_url_test.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"strings"
+	"testing"
+
+	"helm.sh/helm/v4/pkg/registry"
+)
+
+// buildOCIRef builds the full OCI reference with version tag.
+// This replicates the logic in loadChartFromOCI for testing.
+func buildOCIRef(chartRef string, version string) string {
+	ref := strings.TrimPrefix(chartRef, registry.OCIScheme+"://")
+
+	// Check if the chart name (after the last /) already has a version tag
+	// We need to check only the chart name part, not the whole ref, because
+	// the registry URL may contain a port number (e.g., localhost:5001/chart)
+	// which would incorrectly match a simple Contains(ref, ":") check
+	lastSlash := strings.LastIndex(ref, "/")
+	chartName := ref
+	if lastSlash >= 0 {
+		chartName = ref[lastSlash+1:]
+	}
+	if version != "" && !strings.Contains(chartName, ":") {
+		ref = ref + ":" + version
+	}
+	return ref
+}
+
+func TestBuildOCIRef(t *testing.T) {
+	tests := []struct {
+		name     string
+		chartRef string
+		version  string
+		expected string
+	}{
+		{
+			name:     "standard OCI URL with version",
+			chartRef: "oci://ghcr.io/project/chart",
+			version:  "1.0.0",
+			expected: "ghcr.io/project/chart:1.0.0",
+		},
+		{
+			name:     "OCI URL with port and version",
+			chartRef: "oci://localhost:5001/project/chart",
+			version:  "2.5.0",
+			expected: "localhost:5001/project/chart:2.5.0",
+		},
+		{
+			name:     "OCI URL with port no subdirectory",
+			chartRef: "oci://localhost:5001/chart",
+			version:  "1.2.3",
+			expected: "localhost:5001/chart:1.2.3",
+		},
+		{
+			name:     "OCI URL already has version tag",
+			chartRef: "oci://ghcr.io/project/chart:existing",
+			version:  "1.0.0",
+			expected: "ghcr.io/project/chart:existing",
+		},
+		{
+			name:     "OCI URL with port already has version tag",
+			chartRef: "oci://localhost:5001/project/chart:existing",
+			version:  "2.0.0",
+			expected: "localhost:5001/project/chart:existing",
+		},
+		{
+			name:     "empty version should not append tag",
+			chartRef: "oci://ghcr.io/project/chart",
+			version:  "",
+			expected: "ghcr.io/project/chart",
+		},
+		{
+			name:     "nested path with port",
+			chartRef: "oci://192.168.1.100:5000/helm-charts/stable/nginx",
+			version:  "15.0.0",
+			expected: "192.168.1.100:5000/helm-charts/stable/nginx:15.0.0",
+		},
+		{
+			name:     "without oci:// prefix",
+			chartRef: "localhost:5001/charts/app",
+			version:  "3.0.0",
+			expected: "localhost:5001/charts/app:3.0.0",
+		},
+		{
+			name:     "registry with high port number",
+			chartRef: "oci://registry.internal:32000/myorg/mychart",
+			version:  "0.1.0",
+			expected: "registry.internal:32000/myorg/mychart:0.1.0",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := buildOCIRef(tt.chartRef, tt.version)
+			if result != tt.expected {
+				t.Errorf("buildOCIRef(%q, %q) = %q, want %q",
+					tt.chartRef, tt.version, result, tt.expected)
+			}
+		})
+	}
+}