applied suggestions from code review

src/sentry_scope.c

@@ -74,7 +74,6 @@ get_scope(void)
     g_scope.contexts = sentry_value_new_object();
     sentry_value_set_by_key(g_scope.contexts, "os", sentry__get_os_context());
     g_scope.breadcrumbs = sentry_value_new_list();
-    sentry_value_append(g_scope.breadcrumbs, sentry_value_new_int32(1));
     g_scope.level = SENTRY_LEVEL_ERROR;
     g_scope.client_sdk = get_client_sdk();
     g_scope.transaction_object = NULL;

src/sentry_value.c

@@ -629,6 +629,19 @@ sentry__value_clone(sentry_value_t value)
     }
 }
 
+/**
+ * This appends `v` to the List `value`.
+ * To make this work properly as a ring buffer, the value list needs to have
+ * the ring buffer start index as the first element
+ * (e.g, 1 until max is exceeded, then it will update for each added item)
+ *
+ * It will remove the oldest value in the list, in case the total number of
+ * items would exceed `max`.
+ *
+ * The list is of size `max + 1` to store the start index.
+ *
+ * Returns 0 on success.
+ */
 int
 sentry__value_append_ringbuffer(
     sentry_value_t value, sentry_value_t v, size_t max)
@@ -639,10 +652,17 @@ sentry__value_append_ringbuffer(
     }
 
     list_t *l = thing->payload._ptr;
-
+    if (l->len == 0) {
+        sentry_value_append(value, sentry_value_new_int32(1));
+    }
     if (l->len < max + 1) {
         return sentry_value_append(value, v);
     }
+    if (l->len > max + 1) {
+        SENTRY_WARNF("Cannot reduce Ringbuffer list size from %d to %d.",
+            l->len - 1, max);
+        goto fail;
+    }
     const int32_t start_idx = sentry_value_as_int32(l->items[0]);
 
     sentry_value_decref(l->items[start_idx]);
@@ -835,6 +855,9 @@ sentry__value_ring_buffer_to_list(const sentry_value_t rb)
         return sentry_value_new_null();
     }
     const list_t *rb_list = thing->payload._ptr;
+    if (rb_list->len == 0) {
+        return sentry_value_new_list();
+    }
     const size_t start_idx = sentry_value_as_int32(rb_list->items[0]);
 
     sentry_value_t rv = sentry_value_new_list();

src/sentry_value.h

@@ -81,14 +81,12 @@ sentry_value_t sentry__value_clone(sentry_value_t value);
 
 /**
  * This appends `v` to the List `value`.
- * To make this work properly as a ring buffer, the value list needs to have
- * the ring buffer start index as the first element
- * (e.g, 1 until max is exceeded, then it will update for each added item)
  *
- * It will remove the oldest value in the list, in case the total number of
- * items would exceed `max`.
+ * On non-full lists, exponentially reallocate space to accommodate new values
+ * (until we reach `max`). After reaching max, the oldest value is removed to
+ * make space for the new one.
  *
- * The list is of size `max + 1` to store the start index.
+ * `max` should stay fixed over multiple invocations.
  *
  * Returns 0 on success.
  */