Fix list callback signatures

Make sure that all parameters and return values of list callback
functions exactly match the callback function type. This is required
to pass clang's Control Flow Integrity checks and to allow compilation
to asm.js with Emscripten.

Also change the `user` parameter type from `const void *` to `void *`.

1 files changed, 2 insertions, 2 deletions

diff --git a/list.c b/list.c
index caa83331..24da6b1e 100644
--- a/list.c
+++ b/list.c
@@ -673,7 +673,7 @@ xmlListSort(xmlListPtr l)
  * apply the walker function to it
  */
 void
-xmlListWalk(xmlListPtr l, xmlListWalker walker, const void *user) {
+xmlListWalk(xmlListPtr l, xmlListWalker walker, void *user) {
     xmlLinkPtr lk;
 
     if ((l == NULL) || (walker == NULL))
@@ -694,7 +694,7 @@ xmlListWalk(xmlListPtr l, xmlListWalker walker, const void *user) {
  * apply the walker function to it
  */
 void
-xmlListReverseWalk(xmlListPtr l, xmlListWalker walker, const void *user) {
+xmlListReverseWalk(xmlListPtr l, xmlListWalker walker, void *user) {
     xmlLinkPtr lk;
 
     if ((l == NULL) || (walker == NULL))