Fix risky signature of `wchar_to_utf8chars()`. Add `ll_convert()` alias.

`wchar_to_utf8chars()` used to require a `char*` output buffer with no length,
assuming that its caller knew enough to provide a buffer of sufficient length.
In fact a `char[8]` buffer suffices, but nothing in the header indicated that.
Eliminate the output parameter and return `std::string`. Fix the few existing
callers.

Also set an `ll_convert_alias` so that `ll_convert_to<std::string>(llwchar)`
directly calls `wchar_to_utf8chars()`. Replace instances of the workaround
`wstring_to_utf8str(LLWString(1, llwchar))`.

2 files changed, 3 insertions, 3 deletions

diff --git a/indra/newview/llpanelemojicomplete.cpp b/indra/newview/llpanelemojicomplete.cpp
index cb89a5910e..7f72677e34 100644
--- a/indra/newview/llpanelemojicomplete.cpp
+++ b/indra/newview/llpanelemojicomplete.cpp
@@ -280,8 +280,7 @@ void LLPanelEmojiComplete::onCommit()
 {
     if (mCurSelected < mTotalEmojis)
     {
-        LLSD value(wstring_to_utf8str(LLWString(1, mEmojis[mCurSelected].Character)));
-        setValue(value);
+        setValue(ll_convert_to<std::string>(mEmojis[mCurSelected].Character));
         LLUICtrl::onCommit();
     }
 }
diff --git a/indra/newview/llviewermedia.cpp b/indra/newview/llviewermedia.cpp
index 9739cac311..1c8f1a32b9 100644
--- a/indra/newview/llviewermedia.cpp
+++ b/indra/newview/llviewermedia.cpp
@@ -2766,7 +2766,8 @@ bool LLViewerMediaImpl::handleUnicodeCharHere(llwchar uni_char)
         {
             LLSD native_key_data = gViewerWindow->getWindow()->getNativeKeyData();
 
-            mMediaSource->textInput(wstring_to_utf8str(LLWString(1, uni_char)), gKeyboard->currentMask(false), native_key_data);
+            mMediaSource->textInput(ll_convert_to<std::string>(uni_char),
+                                    gKeyboard->currentMask(false), native_key_data);
         }
     }