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>

2 files changed, 10 insertions, 8 deletions

diff --git a/shell/source/sessioninstall/SyncDbusSessionHelper.cxx b/shell/source/sessioninstall/SyncDbusSessionHelper.cxx
index 9b11b2f6f498..df2ef3529145 100644
--- a/shell/source/sessioninstall/SyncDbusSessionHelper.cxx
+++ b/shell/source/sessioninstall/SyncDbusSessionHelper.cxx
@@ -12,6 +12,7 @@
 #include <cppuhelper/supportsservice.hxx>
 #include <gio/gio.h>
 #include <memory>
+#include <string_view>
 #include <vector>
 
 using namespace ::com::sun::star::lang;
@@ -37,7 +38,7 @@ namespace
             }
             GError*& getRef() { return m_pError; }
     };
-    GDBusProxy* lcl_GetPackageKitProxy(const OUString& sInterface)
+    GDBusProxy* lcl_GetPackageKitProxy(std::u16string_view sInterface)
     {
         const OString sFullInterface = "org.freedesktop.PackageKit." + OUStringToOString(sInterface, RTL_TEXTENCODING_ASCII_US);
         GDBusProxy* proxy = nullptr;
@@ -66,7 +67,7 @@ namespace
 void request(
     char const * method,
     css::uno::Sequence<OUString> const & resources,
-    OUString const & interaction)
+    std::u16string_view interaction)
 {
     // Keep strings alive until after call to g_dbus_proxy_call_sync
     std::vector<OString> resUtf8;
@@ -79,7 +80,7 @@ void request(
     }
     auto iactUtf8(OUStringToOString(interaction, RTL_TEXTENCODING_UTF8));
     std::shared_ptr<GDBusProxy> proxy(
-        lcl_GetPackageKitProxy("Modify2"), GObjectDeleter<GDBusProxy>());
+        lcl_GetPackageKitProxy(u"Modify2"), GObjectDeleter<GDBusProxy>());
     GErrorWrapper error;
     std::shared_ptr<GVariant> result(g_dbus_proxy_call_sync(
         proxy.get(), method,
@@ -182,7 +183,7 @@ void SAL_CALL SyncDbusSessionHelper::IsInstalled( const OUString& sPackagename,
 {
     const OString sPackagenameAscii = OUStringToOString(sPackagename, RTL_TEXTENCODING_ASCII_US);
     const OString sInteractionAscii = OUStringToOString(sInteraction, RTL_TEXTENCODING_ASCII_US);
-    std::shared_ptr<GDBusProxy> proxy(lcl_GetPackageKitProxy("Query"), GObjectDeleter<GDBusProxy>());
+    std::shared_ptr<GDBusProxy> proxy(lcl_GetPackageKitProxy(u"Query"), GObjectDeleter<GDBusProxy>());
     GErrorWrapper error;
     std::shared_ptr<GVariant> result(g_dbus_proxy_call_sync (proxy.get(),
                      "IsInstalled",
diff --git a/shell/source/tools/lngconvex/lngconvex.cxx b/shell/source/tools/lngconvex/lngconvex.cxx
index 7385ad25b531..fc81964494f0 100644
--- a/shell/source/tools/lngconvex/lngconvex.cxx
+++ b/shell/source/tools/lngconvex/lngconvex.cxx
@@ -51,6 +51,7 @@ typedef unsigned short WORD;
 #include <map>
 #include <iterator>
 #include <string>
+#include <string_view>
 
 #ifndef _WIN32
 #include <cstring>
@@ -70,11 +71,11 @@ void ShowUsage()
     std::cout << "-rcf Name of the resource file footer" << std::endl;
 }
 
-OUString OStringToOUString(const OString& str)
-{ return OStringToOUString(str, osl_getThreadTextEncoding()); }
+OUString OStringToOUString(std::string_view str)
+{ return rtl::OStringToOUString(str, osl_getThreadTextEncoding()); }
 
-OString OUStringToOString(const OUString& str)
-{ return OUStringToOString(str, osl_getThreadTextEncoding()); }
+OString OUStringToOString(std::u16string_view str)
+{ return rtl::OUStringToOString(str, osl_getThreadTextEncoding()); }
 
 /** Get the directory where the module
     is located as system directory, the