Use stack based char array to generate JSON keys

This saves us from having to allocate memory in a loop. It simplifies
the code a little bit too, by removing an if statement that was far away
from the code that generated the requirement to call it.

diff --git a/src/modules/rlm_json/json.c b/src/modules/rlm_json/json.c
index 17f24ba143701ee41c7d2ca0a176645e2e6dd1a5..95c17b559242e26505ad2ef5cd6fbb43535de45f 100644 (file)
--- a/src/modules/rlm_json/json.c
+++ b/src/modules/rlm_json/json.c
@@ -333,6 +333,7 @@ const char *fr_json_afrom_pair_list(TALLOC_CTX *ctx, VALUE_PAIR **vps, const cha
        VALUE_PAIR              *vp;
        struct json_object      *obj;
        const char              *p;
+       char                    buf[FR_DICT_ATTR_MAX_NAME_LEN + 32];
 
        MEM(obj = json_object_new_object());
 
@@ -341,10 +342,12 @@ const char *fr_json_afrom_pair_list(TALLOC_CTX *ctx, VALUE_PAIR **vps, const cha
                fr_dict_enum_t const    *dv;
                struct json_object      *vp_object, *values, *value, *type_name;
 
+               name_with_prefix = vp->da->name;
                if (prefix) {
-                       MEM(name_with_prefix = talloc_asprintf(ctx, "%s:%s", prefix, vp->da->name));
-               } else {
-                       name_with_prefix = vp->da->name;
+                       int len = snprintf(buf, sizeof(buf), "%s:%s", prefix, vp->da->name);
+                       if (len == (int)strlen(buf)) {
+                               name_with_prefix = buf;
+                       }
                }
 
                /*
@@ -370,8 +373,6 @@ const char *fr_json_afrom_pair_list(TALLOC_CTX *ctx, VALUE_PAIR **vps, const cha
                        return NULL;
                }
 
-               if (prefix) talloc_const_free(name_with_prefix);
-
                MEM(value = json_object_from_value_data(ctx, vp->da->type, vp->da, &vp->data));
                json_object_array_add(values, value);