func_uri: URIENCODE/URIDECODE - allow empty strings as argument

Previously these two dialplan functions would issue warnings and
return failure when an empty string is used as the argument. Now
they will not issue a warning and will successfully return an
empty string.

ASTERISK-23911 #close
Reported by: Matt Jordan
Review: https://reviewboard.asterisk.org/r/3745/
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Merged revisions 418641 from http://svn.asterisk.org/svn/asterisk/branches/1.8
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Merged revisions 418649 from http://svn.asterisk.org/svn/asterisk/branches/11
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Merged revisions 418650 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@418654 65c4cc65-6c06-0410-ace0-fbb531ad65f3

funcs/func_uri.c

@@ -76,8 +76,8 @@ static int uriencode(struct ast_channel *chan, const char *cmd, char *data,
 		     char *buf, size_t len)
 {
 	if (ast_strlen_zero(data)) {
-		ast_log(LOG_WARNING, "Syntax: URIENCODE(<data>) - missing argument!\n");
-		return -1;
+		buf[0] = '\0';
+		return 0;
 	}
 
 	ast_uri_encode(data, buf, len, ast_uri_http);
@@ -90,8 +90,8 @@ static int uridecode(struct ast_channel *chan, const char *cmd, char *data,
 		     char *buf, size_t len)
 {
 	if (ast_strlen_zero(data)) {
-		ast_log(LOG_WARNING, "Syntax: URIDECODE(<data>) - missing argument!\n");
-		return -1;
+		buf[0] = '\0';
+		return 0;
 	}
 
 	ast_copy_string(buf, data, len);