conf.c: fix handling of NULL string values

Make sure that we do not crash when encountering configuration nodes
with a NULL string value, or that at least we run into an assert().

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

diff --git a/src/conf.c b/src/conf.c
index d1fa109772d355dc7cab5941056e41c762deb290..97bf5e126bad4df0330338ba7abd25c9badc5695 100644 (file)
--- a/src/conf.c
+++ b/src/conf.c
@@ -1242,20 +1242,17 @@ static int parse_defs(snd_config_t *father, input_t *input, int skip, int overri
 static void string_print(char *str, int id, snd_output_t *out)
 {
        unsigned char *p = (unsigned char *)str;
+       if (!p || !*p) {
+               snd_output_puts(out, "''");
+               return;
+       }
        if (!id) {
                switch (*p) {
-               case 0:
-                       assert(0);
-                       break;
                case '0' ... '9':
                case '-':
                        goto quoted;
                }
        }
-       if (!*p) {
-               snd_output_puts(out, "''");
-               return;
-       }
  loop:
        switch (*p) {
        case 0:
@@ -2445,6 +2442,7 @@ int snd_config_save(snd_config_t *config, snd_output_t *out)
                } \
                if (snd_config_get_string(res, &key) < 0) \
                        break; \
+               assert(key); \
                if (!first && (strcmp(key, old_key) == 0 || maxloop <= 0)) { \
                        if (maxloop == 0) \
                                SNDERR("maximum loop count reached (circular configuration?)"); \
@@ -2670,6 +2668,7 @@ static int snd_config_hooks_call(snd_config_t *root, snd_config_t *config, snd_c
                SNDERR("Invalid type for field func");
                return err;
        }
+       assert(str);
        err = snd_config_search_definition(root, "hook_func", str, &func_conf);
        if (err >= 0) {
                snd_config_iterator_t i, next;
@@ -2918,6 +2917,7 @@ int snd_config_hook_load_for_all_cards(snd_config_t *root, snd_config_t *config,
                        if (snd_config_search(root, fdriver, &n) >= 0) {
                                if (snd_config_get_string(n, &driver) < 0)
                                        goto __err;
+                               assert(driver);
                                while (1) {
                                        char *s = strchr(driver, '.');
                                        if (s == NULL)
@@ -3414,7 +3414,7 @@ static int _snd_config_expand(snd_config_t *src,
                        snd_config_t *val;
                        snd_config_t *vars = private_data;
                        snd_config_get_string(src, &s);
-                       if (*s == '$') {
+                       if (s && *s == '$') {
                                s++;
                                if (snd_config_search(vars, s, &val) < 0)
                                        return 0;
@@ -3466,6 +3466,7 @@ static int _snd_config_evaluate(snd_config_t *src,
                        SNDERR("Invalid type for @func");
                        return err;
                }
+               assert(str);
                err = snd_config_search_definition(root, "func", str, &func_conf);
                if (err >= 0) {
                        snd_config_iterator_t i, next;
@@ -3878,7 +3879,7 @@ static int parse_args(snd_config_t *subs, const char *str, snd_config_t *defs)
                        goto _err;
                }
                err = snd_config_get_string(typ, &tmp);
-               if (err < 0)
+               if (err < 0 || !tmp)
                        goto _invalid_type;
                if (strcmp(tmp, "integer") == 0) {
                        long v;