ext/odbc: get exact length for quoted connection strings

strlen has to scan the string until the end of the null terminator, we
might as well do the same but scan for end quotes that need escaping.

Author: NattyNarwhal

main/php_odbc_utils.c

@@ -75,8 +75,16 @@ PHPAPI bool php_odbc_connstr_should_quote(const char *str)
  */
 PHPAPI size_t php_odbc_connstr_estimate_quote_length(const char *in_str)
 {
-	/* Assume all '}'. Include '{,' '}', and the null terminator too */
-	return (strlen(in_str) * 2) + 3;
+	/* Start with including the quotes ({}) and the null terminator */
+	size_t size = 3;
+	/* Scan the string like strlen, doubling each } character. */
+	while (*in_str) {
+		size++;
+		if (*in_str++ == '}') {
+			size++;
+		}
+	}
+	return size;
 }
 
 /**