Implement espeak_SetVoiceByName directly from the SetVoiceByName implementation.

src/libespeak-ng/espeak_command.c

 	case ET_VOICE_NAME:
 	{
 		const char *data = the_command->u.my_voice_name;
-		SetVoiceByName(data);
+		espeak_SetVoiceByName(data);
 	}
 		break;
 	case ET_VOICE_SPEC:

src/libespeak-ng/espeak_command.h

 void sync_espeak_SetParameter(espeak_PARAMETER parameter, int value, int relative);
 int sync_espeak_SetVoiceByName(const char *name);
 int sync_espeak_SetVoiceByProperties(espeak_VOICE *voice_selector);
-espeak_ERROR SetVoiceByName(const char *name);
 espeak_ERROR SetVoiceByProperties(espeak_VOICE *voice_selector);
 void SetParameter(int parameter, int value, int relative);
 

src/libespeak-ng/speak_lib.c

 #endif
 
 	if (translator == NULL)
-		SetVoiceByName("default");
+		espeak_SetVoiceByName("default");
 
 	SpeakNextClause(NULL, text, 0);
 
 #endif
 }
 
-ESPEAK_API espeak_ERROR espeak_SetVoiceByName(const char *name)
-{
-	return SetVoiceByName(name);
-}
-
 ESPEAK_API espeak_ERROR espeak_SetVoiceByProperties(espeak_VOICE *voice_selector)
 {
 	return SetVoiceByProperties(voice_selector);

src/libespeak-ng/synthesize.h

 extern int n_soundicon_tab;
 extern SOUND_ICON soundicon_tab[N_SOUNDICON_TAB];
 
-espeak_ERROR SetVoiceByName(const char *name);
 espeak_ERROR SetVoiceByProperties(espeak_VOICE *voice_selector);
 espeak_ERROR LoadMbrolaTable(const char *mbrola_voice, const char *phtrans, int *srate);
 void SetParameter(int parameter, int value, int relative);

src/libespeak-ng/voices.c

 #endif
 }
 
-espeak_ERROR SetVoiceByName(const char *name)
+#pragma GCC visibility push(default)
+
+espeak_ERROR espeak_SetVoiceByName(const char *name)
 {
 	espeak_VOICE *v;
 	int ix;
 	return EE_INTERNAL_ERROR; // voice name not found
 }
 
+#pragma GCC visibility pop
+
 espeak_ERROR SetVoiceByProperties(espeak_VOICE *voice_selector)
 {
 	const char *voice_id;

src/speak-ng.c

 	if (voicename[0] == 0)
 		strcpy(voicename, "default");
 
-	if (SetVoiceByName(voicename) != EE_OK) {
+	if (espeak_SetVoiceByName(voicename) != EE_OK) {
 		memset(&voice_select, 0, sizeof(voice_select));
 		voice_select.languages = voicename;
 		if (SetVoiceByProperties(&voice_select) != EE_OK) {