code cleanup: reduce return of static buffers

src/libespeak-ng/dictionary.c

 	int ix;
 	unsigned int digit_count = 0;
 	char *p;
+	char word_buf[5];
 	const ALPHABET *alphabet;
 	int dict_flags0 = 0;
 	MatchRecord match1 = { 0 };
 
 						if (((alphabet = AlphabetFromChar(letter)) != NULL)  && (alphabet->offset != tr->letter_bits_offset)) {
 							if (tr->langopts.alt_alphabet == alphabet->offset) {
-								sprintf(phonemes, "%c%s", phonSWITCH, WordToString2(tr->langopts.alt_alphabet_lang));
+								sprintf(phonemes, "%c%s", phonSWITCH, WordToString2(word_buf, tr->langopts.alt_alphabet_lang));
 								return 0;
 							}
 							if (alphabet->flags & AL_WORDS) {
 								// switch to the nominated language for this alphabet
-								sprintf(phonemes, "%c%s", phonSWITCH, WordToString2(alphabet->language));
+								sprintf(phonemes, "%c%s", phonSWITCH, WordToString2(word_buf, alphabet->language));
 								return 0;
 							}
 						}

src/libespeak-ng/readclause.c

 	ungot_char = c;
 }
 
-const char *WordToString2(unsigned int word)
+const char *WordToString2(char buf[5], unsigned int word)
 {
 	// Convert a language mnemonic word into a string
 	int ix;
-	static char buf[5];
 	char *p;
 
-	MAKE_MEM_UNDEFINED(&buf, sizeof(buf));
-
 	p = buf;
 	for (ix = 3; ix >= 0; ix--) {
 		if ((*p = word >> (ix*8)) != 0)
 	return NULL;
 }
 
-static const char *LookupCharName(Translator *tr, int c, bool only)
+static const char *LookupCharName(char buf[60], Translator *tr, int c, bool only)
 {
 	// Find the phoneme string (in ascii) to speak the name of character c
 	// Used for punctuation characters and symbols
 	char phonemes[60];
 	const char *lang_name = NULL;
 	char *string;
-	static char buf[60];
-
-	MAKE_MEM_UNDEFINED(&buf, sizeof(buf));
 
 	buf[0] = 0;
 	flags[0] = 0;
 	int bufix1;
 	char buf[200];
 	char ph_buf[30];
+	char cn_buf[60];
 
 	c2 = *c2_ptr;
 	buf[0] = 0;
 				punctname = ph_buf; // use word for 'period' instead of 'dot'
 		}
 		if (punctname == NULL)
-			punctname = LookupCharName(tr, c1, false);
+			punctname = LookupCharName(cn_buf, tr, c1, false);
 
 		if (punctname == NULL)
 			return -1;
 				char *p2;
 
 				p2 = &buf[ix];
-				sprintf(p2, "%s", LookupCharName(tr, c1, true));
+				char cn_buf[60];
+				sprintf(p2, "%s", LookupCharName(cn_buf, tr, c1, true));
 				if (p2[0] != 0) {
 					ix += strlen(p2);
 					announced_punctuation = c1;
 	} else {
 		SetWordStress(tr2, phonemes, flags, -1, 0);
 	    DecodePhonemes(phonemes, phonemes2);
-	    sprintf(buf, "[\002_^_%s %s _^_%s]]", ESPEAKNG_DEFAULT_VOICE, phonemes2, WordToString2(tr->translator_name));
+			char wbuf[5];
+	    sprintf(buf, "[\002_^_%s %s _^_%s]]", ESPEAKNG_DEFAULT_VOICE, phonemes2, WordToString2(wbuf, tr->translator_name));
     }
-}
+}

src/libespeak-ng/readclause.h

 
 int clause_type_from_codepoint(uint32_t c);
 int Eof(void);
-const char *WordToString2(unsigned int word);
+const char *WordToString2(char buf[5], unsigned int word);
 int AddNameData(const char *name,
                 int wide);
 int ReadClause(Translator *tr,

src/libespeak-ng/translateword.c

 			char hangul_buf[12];
 
 			// speak in the language for this alphabet (or English)
-			ph_buf[2] = SetTranslator3(WordToString2(language));
+			char word_buf[5];
+			ph_buf[2] = SetTranslator3(WordToString2(word_buf, language));
 
 			if (translator3 != NULL) {
 				int code;

src/libespeak-ng/voices.c

 
 	if ((voice_select2.languages == NULL) || (voice_select2.languages[0] == 0)) {
 		// no language is specified. Get language from the named voice
-		static char buf[60];
-
-		MAKE_MEM_UNDEFINED(&buf, sizeof(buf));
+		char buf[60];
 
 		if (voice_select2.name == NULL) {
 			if ((voice_select2.name = voice_select2.identifier) == NULL)