Comment 2 for bug 1008600

Sometimes a hook manipulates the config tree, which makes currently
running iterators point to freed memory. As a workaround, make two
copies, one for the iterators and another for the hooks.

BugLink: https://bugs.launchpad.net/bugs/1008600
Signed-off-by: David Henningsson <email address hidden>
---
 src/control/namehint.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/control/namehint.c b/src/control/namehint.c
index 8d5e925..28975a4 100644
--- a/src/control/namehint.c
+++ b/src/control/namehint.c
@@ -406,7 +406,7 @@ static const next_devices_t next_devices[] = {
 };
 #endif

-static int add_card(snd_config_t *config, struct hint_list *list, int card)
+static int add_card(snd_config_t *config, snd_config_t *rw_config, struct hint_list *list, int card)
 {
  int err, ok;
  snd_config_t *conf, *n;
@@ -449,7 +449,7 @@ static int add_card(snd_config_t *config, struct hint_list *list, int card)
    ok = 0;
    for (device = 0; err >= 0 && device <= max_device; device++) {
     list->device = device;
- err = try_config(config, list, list->siface, str);
+ err = try_config(rw_config, list, list->siface, str);
     if (err < 0)
      break;
     ok++;
@@ -464,7 +464,7 @@ static int add_card(snd_config_t *config, struct hint_list *list, int card)
   if (err < 0) {
    list->card = card;
    list->device = -1;
- err = try_config(config, list, list->siface, str);
+ err = try_config(rw_config, list, list->siface, str);
   }
   if (err == -ENOMEM)
    goto __error;
@@ -493,7 +493,8 @@ static int get_card_name(struct hint_list *list, int card)
  return 0;
 }

-static int add_software_devices(snd_config_t *config, struct hint_list *list)
+static int add_software_devices(snd_config_t *config, snd_config_t *rw_config,
+ struct hint_list *list)
 {
  int err;
  snd_config_t *conf, *n;
@@ -509,7 +510,7 @@ static int add_software_devices(snd_config_t *config, struct hint_list *list)
    continue;
   list->card = -1;
   list->device = -1;
- err = try_config(config, list, list->siface, str);
+ err = try_config(rw_config, list, list->siface, str);
   if (err == -ENOMEM)
    return -ENOMEM;
  }
@@ -547,7 +548,7 @@ int snd_device_name_hint(int card, const char *iface, void ***hints)
  struct hint_list list;
  char ehints[24];
  const char *str;
- snd_config_t *conf, *local_config = NULL;
+ snd_config_t *conf, *local_config = NULL, *local_config_rw = NULL;
  snd_config_update_t *local_config_update = NULL;
  snd_config_iterator_t i, next;
  int err;
@@ -557,6 +558,7 @@ int snd_device_name_hint(int card, const char *iface, void ***hints)
  err = snd_config_update_r(&local_config, &local_config_update, NULL);
  if (err < 0)
   return err;
+ err = snd_config_copy(&local_config_rw, local_config);
  list.list = NULL;
  list.count = list.allocated = 0;
  list.siface = iface;
@@ -586,9 +588,9 @@ int snd_device_name_hint(int card, const char *iface, void ***hints)
  if (card >= 0) {
   err = get_card_name(&list, card);
   if (err >= 0)
- err = add_card(local_config, &list, card);
+ err = add_card(local_config, local_config_rw, &list, card);
  } else {
- add_software_devices(local_config, &list);
+ add_software_devices(local_config, local_config_rw, &list);
   err = snd_card_next(&card);
   if (err < 0)
    goto __error;
@@ -596,7 +598,7 @@ int snd_device_name_hint(int card, const char *iface, void ***hints)
    err = get_card_name(&list, card);
    if (err < 0)
     goto __error;
- err = add_card(local_config, &list, card);
+ err = add_card(local_config, local_config_rw, &list, card);
    if (err < 0)
     goto __error;
    err = snd_card_next(&card);
@@ -630,6 +632,8 @@ int snd_device_name_hint(int card, const char *iface, void ***hints)
         if (list.cardname)
          free(list.cardname);
  }
+ if (local_config_rw)
+ snd_config_delete(local_config_rw);
  if (local_config)
   snd_config_delete(local_config);
  if (local_config_update)
--
1.8.3.2