Return an espeak_ng_STATUS code in LoadSpectSeq.

src/include/espeak-ng/espeak_ng.h

 	ENS_MBROLA_VOICE_NOT_FOUND   = 0x100008FF,
 	ENS_EVENT_BUFFER_FULL        = 0x100009FF,
 	ENS_NOT_SUPPORTED            = 0x10000AFF,
+	ENS_UNSUPPORTED_SPECT_FORMAT = 0x10000BFF,
+	ENS_NO_SPECT_FRAMES          = 0x10000CFF,
 } espeak_ng_STATUS;
 
 typedef enum {

src/libespeak-ng/compiledata.c

 	}
 
 	snprintf(filename, sizeof(filename), "%s/../phsource/%s", path_home, path);
-	LoadSpectSeq(spectseq, filename);
-
-	if (spectseq->frames == NULL) {
-		error("Bad vowel file, no frames: '%s'", path);
+	if (LoadSpectSeq(spectseq, filename) != ENS_OK) {
+		error("Bad vowel file: '%s'", path);
 		SpectSeqDestroy(spectseq);
 		return 0;
 	}

src/libespeak-ng/spect.c

 
 #include "config.h"
 
+#include <errno.h>
 #include <stdio.h>
 #if HAVE_STDINT_H
 #include <stdint.h>
 	return (spect->frames[ix]->time - spect->frames[frame]->time) * 1000.0 + adjust;
 }
 
-int LoadSpectSeq(SpectSeq *spect, const char *filename)
+espeak_ng_STATUS LoadSpectSeq(SpectSeq *spect, const char *filename)
 {
 	short n, temp;
 	int ix;
 	FILE *stream = fopen(filename, "rb");
 	if (stream == NULL) {
 		fprintf(stderr, "Failed to open: '%s'", filename);
-		return 0;
+		return errno;
 	}
 
 	fread(&id1, sizeof(uint32_t), 1, stream);
 	else {
 		fprintf(stderr, "Unsupported spectral file format.\n");
 		fclose(stream);
-		return 1;
+		return ENS_UNSUPPORTED_SPECT_FORMAT;
 	}
 
 	fread(&name_len, sizeof(uint32_t), 1, stream);
 
 	if (n == 0) {
 		fclose(stream);
-		return 0;
+		return ENS_NO_SPECT_FRAMES;
 	}
 
 	if (spect->frames != NULL) {
 			spect->frames[ix]->length_adjust = spect->frames[ix]->length - GetFrameLength(spect, ix);
 	}
 	fclose(stream);
-	return 0;
+	return ENS_OK;
 }

src/libespeak-ng/spect.h

 /*
  * Copyright (C) 2005 to 2007 by Jonathan Duddington
  * email: [email protected]
- * Copyright (C) 2013-2015 Reece H. Dunn
+ * Copyright (C) 2013-2016 Reece H. Dunn
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
 
 SpectSeq *SpectSeqCreate();
 void SpectSeqDestroy(SpectSeq *spect);
-int LoadSpectSeq(SpectSeq *spect, const char *filename);
+espeak_ng_STATUS LoadSpectSeq(SpectSeq *spect, const char *filename);
 
 #ifdef __cplusplus
 }