lowercase header transformation destroys custom headers of translation software

When parsing a pot file with this package, all header names are transformed to lowercase first, then upon saving, each letter after a dash in the name is transformed to uppercase. However, some translation software writes custom headers that are case-sensitive, like Poedit:

"X-Poedit-KeywordsList: "
"__;_e;_n:1,2;_x:1,2c;_ex:1,2c;_nx:4c,1,2;esc_attr__;esc_attr_e;esc_attr_x:1,"
"2c;esc_html__;esc_html_e;esc_html_x:1,2c;_n_noop:1,2;_nx_noop:3c,1,2;__"
"ngettext_noop:1,2\n"
"X-Source-Language: en\n"
"X-Poedit-SearchPath-0: .\n"
"X-Poedit-SearchPathExcluded-0: *.min.js\n"

After handling my pot file with this package, I’m no longer able to update the translation strings from source in Poedit, because they are now written like this:

"X-Poedit-Keywordslist: "
"__;_e;_n:1,2;_x:1,2c;_ex:1,2c;_nx:4c,1,2;esc_attr__;esc_attr_e;esc_attr_x:1,"
"2c;esc_html__;esc_html_e;esc_html_x:1,2c;_n_noop:1,2;_nx_noop:3c,1,2;__"
"ngettext_noop:1,2\n"
"X-Source-Language: en\n"
"X-Poedit-Searchpath-0: .\n"
"X-Poedit-Searchpathexcluded-0: *.min.js\n"

Could you add an option to keep the header names untouched (or it might be a good idea not transforming any custom headers starting with X- by default?)? Or is Poedit simply violating some standards regarding header naming convention in pot files?

[vslavik]

Or is Poedit simply violating some standards regarding header naming convention in pot files?

Poedit developer here: GNU gettext headers are case sensitive. E.g. changing Language to language will cause all GNU gettext tools such as msgfmt to warn about missing Language header.

[smhg]

No problem! Thanks for the update!