app_voicemail.c: Support multiple file formats for forwarded messages.

If you specify multiple formats in voicemail.conf, eg. "format = gsm|wav"
and are using realtime ODBC backend, only the first format gets stored
in the database. So when you forward a message later on, there is a bug
generating the email, related to the stored format (GSM) being different
than the desired email format (WAV) specified for the user. Sox can
handle this, but Asterisk needs to tell sox exactly what to do.

ASTERISK-22192

Change-Id: I7321e7f7e7c58adbf41dd4fd7191c887b9b2eafd

apps/app_voicemail.c

@@ -5398,12 +5398,33 @@ static int add_email_attachment(FILE *p, struct ast_vm_user *vmu, char *format,
 	char sox_gain_tmpdir[PATH_MAX];
 	char *file_to_delete = NULL, *dir_to_delete = NULL;
 	int res;
+	char altfname[PATH_MAX] = "";
+	int altused = 0;
+	char altformat[80] = "";
+	char *c = NULL;
 	/* Eww. We want formats to tell us their own MIME type */
 	char *mime_type = (!strcasecmp(format, "ogg")) ? "application/" : "audio/x-";
+	/* Users of multiple file formats need special attention. */
+	snprintf(fname, sizeof(fname), "%s.%s", attach, format);
+	if (!ast_file_is_readable(fname)) {
+		ast_copy_string(altformat, vmfmts, sizeof(altformat));
+		c = strchr(altformat, '|');
+		if (c) {
+			*c = '\0';
+		}
+		ast_log(AST_LOG_WARNING, "Failed to open file: %s: %s - trying first/alternate format %s\n", fname, strerror(errno), altformat);
+		snprintf(altfname, sizeof(altfname), "%s.%s", attach, altformat);
+		if (!ast_file_is_readable(altfname)) {
+			ast_log(AST_LOG_WARNING, "Failed to open file: %s: %s - alternate format %s failure\n", altfname, strerror(errno), altformat);
+		} else {
+			altused = 1;
+		}
+	}
+
 	/* This 'while' loop will only execute once. We use it so that we can 'break' */
-	while (vmu->volgain < -.001 || vmu->volgain > .001) {
+	while (vmu->volgain < -.001 || vmu->volgain > .001 || altused) {
 		char tmpdir[PATH_MAX];
 		create_dirpath(tmpdir, sizeof(tmpdir), vmu->context, vmu->mailbox, "tmp");
@@ -5429,8 +5450,29 @@ static int add_email_attachment(FILE *p, struct ast_vm_user *vmu, char *format,
 				break;
 			}
-			res = snprintf(sox_gain_cmd, sizeof(sox_gain_cmd), "sox -v %.4f %s.%s %s",
-						   vmu->volgain, attach, format, fname);
+			if (!altused) {
+				res = snprintf(sox_gain_cmd, sizeof(sox_gain_cmd), "sox -v %.4f %s.%s %s",
+							   vmu->volgain, attach, format, fname);
+			} else {
+				if (!strcasecmp(format, "wav")) {
+					if (vmu->volgain < -.001 || vmu->volgain > .001) {
+						res = snprintf(sox_gain_cmd, sizeof(sox_gain_cmd), "sox -v %.4f %s.%s -e signed-integer -b 16 %s",
+									   vmu->volgain, attach, altformat, fname);
+					} else {
+						res = snprintf(sox_gain_cmd, sizeof(sox_gain_cmd), "sox %s.%s -e signed-integer -b 16 %s",
+									   attach, altformat, fname);
+					}
+				} else {
+					if (vmu->volgain < -.001 || vmu->volgain > .001) {
+						res = snprintf(sox_gain_cmd, sizeof(sox_gain_cmd), "sox -v %.4f %s.%s %s",
+									   vmu->volgain, attach, altformat, fname);
+					} else {
+						res = snprintf(sox_gain_cmd, sizeof(sox_gain_cmd), "sox %s.%s %s",
+									   attach, altformat, fname);
+					}
+				}
+			}
+
 			if (res >= sizeof(sox_gain_cmd)) {
 				ast_log(LOG_ERROR, "Failed to generate sox command, out of buffer space\n");
 				break;