Adapt the remaining OUString functions to std string_view

...for LIBO_INTERNAL_ONLY.  These had been missed by
1b43cceaea2084a0489db68cd0113508f34b6643 "Make many OUString functions take
std::u16string_view parameters" because they did not match the multi-overload
pattern that was addressed there, but they nevertheless benefit from being
changed just as well (witness e.g. the various resulting changes from copy() to
subView()).

This showed a conversion from OStringChar to std::string_view to be missing
(while the corresponding conversion form OUStringChar to std::u16string_view was
already present).

The improvement to loplugin:stringadd became necessary to fix

> [CPT] compilerplugins/clang/test/stringadd.cxx
> error: 'error' diagnostics expected but not seen:
>   File ~/lo/core/compilerplugins/clang/test/stringadd.cxx Line 43 (directive at ~/lo/core/compilerplugins/clang/test/stringadd.cxx:42): simplify by merging with the preceding assignment [loplugin:stringadd]
>   File ~/lo/core/compilerplugins/clang/test/stringadd.cxx Line 61 (directive at ~/lo/core/compilerplugins/clang/test/stringadd.cxx:60): simplify by merging with the preceding assignment [loplugin:stringadd]
> 2 errors generated.

Change-Id: Ie40de0616a66e60e289c1af0ca60aed6f9ecc279
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/107602
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

3 files changed, 4 insertions, 4 deletions

diff --git a/i18nlangtag/source/isolang/isolang.cxx b/i18nlangtag/source/isolang/isolang.cxx
index ecab61113ab1..ae1b42ba3ab0 100644
--- a/i18nlangtag/source/isolang/isolang.cxx
+++ b/i18nlangtag/source/isolang/isolang.cxx
@@ -1416,8 +1416,8 @@ LanguageType MsLangId::Conversion::convertIsoNamesToLanguage( const OUString& rL
 
 
 // static
-LanguageType MsLangId::Conversion::convertIsoNamesToLanguage( const OString& rLang,
-        const OString& rCountry )
+LanguageType MsLangId::Conversion::convertIsoNamesToLanguage( std::string_view rLang,
+        std::string_view rCountry )
 {
     OUString aLang = OStringToOUString( rLang, RTL_TEXTENCODING_ASCII_US);
     OUString aCountry = OStringToOUString( rCountry, RTL_TEXTENCODING_ASCII_US);
diff --git a/i18nlangtag/source/languagetag/languagetag.cxx b/i18nlangtag/source/languagetag/languagetag.cxx
index 2f77ee148f71..70895cab1651 100644
--- a/i18nlangtag/source/languagetag/languagetag.cxx
+++ b/i18nlangtag/source/languagetag/languagetag.cxx
@@ -1521,7 +1521,7 @@ void LanguageTag::convertFromRtlLocale()
     if (maLocale.Variant.isEmpty())
         return;
 
-    OString aStr = OUStringToOString( maLocale.Language + "_" + maLocale.Country + maLocale.Variant,
+    OString aStr = OUStringToOString(maLocale.Language, RTL_TEXTENCODING_UTF8) + "_" + OUStringToOString(OUString(maLocale.Country + maLocale.Variant),
             RTL_TEXTENCODING_UTF8);
     /* FIXME: let liblangtag parse this entirely with
      * lt_tag_convert_from_locale() but that needs a patch to pass the
diff --git a/i18nlangtag/source/languagetag/languagetagicu.cxx b/i18nlangtag/source/languagetag/languagetagicu.cxx
index 18d37f704773..c35e7a85ef8b 100644
--- a/i18nlangtag/source/languagetag/languagetagicu.cxx
+++ b/i18nlangtag/source/languagetag/languagetagicu.cxx
@@ -35,7 +35,7 @@ icu::Locale LanguageTagIcu::getIcuLocale( const LanguageTag & rLanguageTag )
 
 
 // static
-icu::Locale LanguageTagIcu::getIcuLocale( const LanguageTag & rLanguageTag, const OUString & rVariant, const OUString & rKeywords )
+icu::Locale LanguageTagIcu::getIcuLocale( const LanguageTag & rLanguageTag, std::u16string_view rVariant, std::u16string_view rKeywords )
 {
     /* FIXME: how should this work with any BCP47? */
     return icu::Locale(