fix(version): avoid false range detection on prerelease x/X

`isVersionRange` checked for `x`/`X` across the entire version
string, misclassifying exact versions like `1.0.0-fix`,
`2.0.0-next`, or `1.0.0+exp` as ranges.

Signed-off-by: Benoit Tigeot <benoit.tigeot@lifen.fr>
(cherry picked from commit 740174a2b1)

pkg/repo/v1/index.go

@@ -178,7 +178,14 @@ func (i IndexFile) SortEntries() {
 // isVersionRange checks if the version string is a range constraint (e.g., "^1", "~1.10")
 // rather than an exact version (e.g., "1.10.0").
 func isVersionRange(version string) bool {
-	return strings.ContainsAny(version, "^~<>=!*xX") || strings.Contains(version, "||") || strings.Contains(version, " - ")
+	if strings.ContainsAny(version, "^~<>=!*") || strings.Contains(version, "||") || strings.Contains(version, " - ") {
+		return true
+	}
+	core := version
+	if idx := strings.IndexAny(version, "-+"); idx != -1 {
+		core = version[:idx]
+	}
+	return strings.ContainsAny(core, "xX")
 }
 
 // Get returns the ChartVersion for the given name.

pkg/repo/v1/index_test.go

@@ -745,6 +745,10 @@ func TestIsVersionRange(t *testing.T) {
 		{"1.0.0 - 2.0.0", true},
 		{"^1.0.0 || ^2.0.0", true},
 		{">=1.0.0 <2.0.0", true},
+		// Exact versions with 'x'/'X' in prerelease or build metadata
+		{"1.0.0-fix", false},
+		{"2.0.0-next", false},
+		{"1.0.0+exp", false},
 	}
 
 	for _, tt := range tests {