fix: Make Crashpad Backend respect max_breadcrumbs setting (#566)

src/backends/sentry_backend_crashpad.cpp

@@ -324,16 +324,20 @@ sentry__crashpad_backend_shutdown(sentry_backend_t *backend)
 }
 
 static void
-sentry__crashpad_backend_add_breadcrumb(
-    sentry_backend_t *backend, sentry_value_t breadcrumb)
+sentry__crashpad_backend_add_breadcrumb(sentry_backend_t *backend,
+    sentry_value_t breadcrumb, const sentry_options_t *options)
 {
     crashpad_state_t *data = (crashpad_state_t *)backend->data;
 
-    bool first_breadcrumb = data->num_breadcrumbs % SENTRY_BREADCRUMBS_MAX == 0;
+    size_t max_breadcrumbs = options->max_breadcrumbs;
+    if (!max_breadcrumbs) {
+        return;
+    }
+
+    bool first_breadcrumb = data->num_breadcrumbs % max_breadcrumbs == 0;
 
     const sentry_path_t *breadcrumb_file
-        = data->num_breadcrumbs % (SENTRY_BREADCRUMBS_MAX * 2)
-            < SENTRY_BREADCRUMBS_MAX
+        = data->num_breadcrumbs % (max_breadcrumbs * 2) < max_breadcrumbs
         ? data->breadcrumb1_path
         : data->breadcrumb2_path;
     data->num_breadcrumbs++;

src/sentry_backend.h

@@ -21,7 +21,8 @@ struct sentry_backend_s {
         sentry_backend_t *, const sentry_options_t *options);
     // NOTE: The breadcrumb is not moved into the hook and does not need to be
     // `decref`-d internally.
-    void (*add_breadcrumb_func)(sentry_backend_t *, sentry_value_t breadcrumb);
+    void (*add_breadcrumb_func)(sentry_backend_t *, sentry_value_t breadcrumb,
+        const sentry_options_t *options);
     void (*user_consent_changed_func)(sentry_backend_t *);
     uint64_t (*get_last_crash_func)(sentry_backend_t *);
     void *data;

src/sentry_core.c

@@ -480,7 +480,8 @@ sentry_add_breadcrumb(sentry_value_t breadcrumb)
     SENTRY_WITH_OPTIONS (options) {
         if (options->backend && options->backend->add_breadcrumb_func) {
             // the hook will *not* take ownership
-            options->backend->add_breadcrumb_func(options->backend, breadcrumb);
+            options->backend->add_breadcrumb_func(
+                options->backend, breadcrumb, options);
         }
         max_breadcrumbs = options->max_breadcrumbs;
     }

src/sentry_value.c

@@ -611,13 +611,19 @@ sentry__value_append_bounded(sentry_value_t value, sentry_value_t v, size_t max)
     //   move 99 items (len - 1)
     //   from 20
 
-    size_t to_move = max - 1;
+    size_t to_move = max >= 1 ? max - 1 : 0;
     size_t to_shift = l->len - to_move;
     for (size_t i = 0; i < to_shift; i++) {
         sentry_value_decref(l->items[i]);
     }
-    memmove(l->items, l->items + (to_shift), to_move * sizeof(l->items[0]));
-    l->items[max - 1] = v;
+    if (to_move) {
+        memmove(l->items, l->items + to_shift, to_move * sizeof(l->items[0]));
+    }
+    if (max >= 1) {
+        l->items[max - 1] = v;
+    } else {
+        sentry_value_decref(v);
+    }
     l->len = max;
     return 0;
 

tests/unit/test_value.c

@@ -477,6 +477,15 @@ SENTRY_TEST(value_collections_leak)
 
     TEST_CHECK_INT_EQUAL(sentry_value_refcount(obj), 3);
 
+    sentry_value_incref(obj);
+    sentry__value_append_bounded(list, obj, 1);
+    TEST_CHECK_INT_EQUAL(sentry_value_refcount(obj), 2);
+
+    sentry_value_incref(obj);
+    sentry__value_append_bounded(list, obj, 0);
+    TEST_CHECK_INT_EQUAL(sentry_value_refcount(obj), 1);
+    TEST_CHECK_INT_EQUAL(sentry_value_get_length(list), 0);
+
     sentry_value_decref(list);
 
     TEST_CHECK_INT_EQUAL(sentry_value_refcount(obj), 1);