xml_isentity: take a const pointer instead of a mutable one

This function does not modify the pointed to data of its parameter, and this
will simplify some upcoming changes.

Related to #1868.

diff --git a/lib/common/xml.c b/lib/common/xml.c
index bafae5d1ff42c4baefa3d335174535f760fdf910..064e2fab303fcd2899dd27098052b0cb156963d0 100644 (file)
--- a/lib/common/xml.c
+++ b/lib/common/xml.c
@@ -17,7 +17,7 @@ static bool isalpha_no_locale(char c) {
  *                          or &#[0-9]*;        (e.g. & )
  *                          or &#x[0-9a-fA-F]*; (e.g. 水 )
  */
-static int xml_isentity(char *s)
+static int xml_isentity(const char *s)
 {
     s++;                       /* already known to be '&' */
     if (*s == ';') { // '&;' is not a valid entity