make normalizeSemver handle 4 component versions (#198)

Signed-off-by: Benji Visser <benji@093b.org>

xeol/search/purl.go

@@ -76,7 +76,13 @@ func ByDistroCpe(store eol.Provider, distro *linux.Release, eolMatchDate time.Ti
 func normalizeSemver(version string) string {
 	// For Ruby versions. Example: 2.5.3p105 -> 2.5.3
 	re := regexp.MustCompile(`^(\d+\.\d+\.\d+)p\d+`)
-	return re.ReplaceAllString(version, "$1")
+	version = re.ReplaceAllString(version, "$1")
+
+	// Handle 4-component versions.
+	// Example: 5.0.20.5194 -> 5.0.20
+	// Example: 2.0.4.RELEASE -> 2.0.4
+	fourCompRe := regexp.MustCompile(`^(\d+\.\d+\.\d+)\.\w+`)
+	return fourCompRe.ReplaceAllString(version, "$1")
 }
 
 func versionLength(version string) int {

xeol/search/purl_test.go

@@ -14,6 +14,14 @@ func TestNormalizeSemver(t *testing.T) {
 		version  string
 		expected string
 	}{
+		{
+			version:  "2.0.4.RELEASE",
+			expected: "2.0.4",
+		},
+		{
+			version:  "5.0.20.51904",
+			expected: "5.0.20",
+		},
 		{
 			version:  "1.2.3",
 			expected: "1.2.3",