RPM spec parser mis-attributes %description -l <lang> <pkg> sections

[reubeno]

Drafted by GitHub Copilot CLI while reviewing PR #132.

internal/rpm/spec/spec.go::GetPackageNameFromSectionHeader does not handle the -l (language) flag pair. It falls through the default: index++ arm in the option switch, which consumes -l but not its argument. The argument is then incorrectly picked up as the package name suffix.

Reproduction

GetPackageNameFromSectionHeader([]string{"%description", "-l", "fr", "devel"})
// returns: "fr"
// expected: "devel"

Impact

Affects every overlay that relies on the parser's package classification, including the existing spec-remove-section overlay and the new spec-remove-subpackage overlay (PR #132). For a sub-package with a localized description, RemoveSubpackage("devel") will remove the main %package devel and English %description devel but leave behind %description -l fr devel, producing a spec that references a sub-package whose preamble is gone — an invalid build.

This is not net-new behavior introduced by PR #132; it was latent in GetPackageNameFromSectionHeader and surfaced by the new overlay's whole-sub-package semantics.

Proposed fix

Add -l to the option-pair switch in GetPackageNameFromSectionHeader so it consumes both the flag and its language argument:

case "-l":
    index += 2

Add fixture tests for %description -l fr devel and %description -l fr -n test-devel.