Feature flags should be modified in-place. (#1940)

* fix(feature flags) refactor feature flags are modified in-place.

* Time limitation for thread collection (#1935)

* fix(threadStack timeout) add time limitation for thread stack

* fix(threadStack timeout) add time limitation for thread stack

CHANGELOG.md

@@ -4,9 +4,15 @@
 
 ### Enhancements
 
-* The maximum time taken to collect Event.threads can now be controlled using 'Configuration.threadCollectionTimeLimitMillis' (default 5000ms)
+* The maximum time taken to collect Event.threads can now be controlled using `Configuration.threadCollectionTimeLimitMillis` (default 5000ms)
   [#1935](https://github.com/bugsnag/bugsnag-android/pull/1935)
 
+### Bug fixes
+
+* Updating existing feature flags no longer causes them to change location.
+  [#1940](https://github.com/bugsnag/bugsnag-android/pull/1940)
+
+
 ## 6.0.0 (2023-11-20)
 
 ### Breaking Changes

bugsnag-android-core/src/main/java/com/bugsnag/android/FeatureFlags.kt

@@ -12,7 +12,6 @@ internal class FeatureFlags(
     }
 
     @Synchronized override fun addFeatureFlag(name: String, variant: String?) {
-        store.remove(name)
         store[name] = variant ?: emptyVariant
     }
 

bugsnag-android-core/src/test/resources/feature_flags_serialization_1.json

@@ -1,9 +1,9 @@
 [
-  {
-    "featureFlag": "demo_mode"
-  },
   {
     "featureFlag": "sample_group",
     "variant": "b"
+  },
+  {
+    "featureFlag": "demo_mode"
   }
 ]

bugsnag-plugin-android-ndk/src/main/jni/featureflags.c

@@ -83,15 +83,11 @@ static void insert_new(bugsnag_event *const event, const char *const name,
   event->feature_flag_count++;
 }
 
-static void modify_at_index_and_reinsert(bugsnag_event *const event,
-                                         const int index,
-                                         const char *const variant) {
-  bsg_feature_flag flag = event->feature_flags[index];
-  free(flag.variant);
-  set_flag_variant(&flag, variant);
-
-  remove_at_index_and_compact(event, index);
-  event->feature_flags[event->feature_flag_count - 1] = flag;
+static void modify_at_index(bugsnag_event *const event, const int index,
+                            const char *const variant) {
+  bsg_feature_flag *flag = &event->feature_flags[index];
+  free(flag->variant);
+  set_flag_variant(flag, variant);
 }
 
 void bsg_set_feature_flag(bugsnag_event *event, const char *const name,
@@ -101,7 +97,7 @@ void bsg_set_feature_flag(bugsnag_event *event, const char *const name,
   if (index == INDEX_NOT_FOUND) {
     insert_new(event, name, variant);
   } else {
-    modify_at_index_and_reinsert(event, index, variant);
+    modify_at_index(event, index, variant);
   }
   bsg_seqlock_release_write(&bsg_feature_flag_lock);
 }

bugsnag-plugin-android-ndk/src/test/cpp/test_featureflags.c

@@ -14,11 +14,11 @@ TEST test_set_feature_flag(void) {
   ASSERT_STR_EQ("sample_group", event->feature_flags[0].name);
   ASSERT_STR_EQ("a", event->feature_flags[0].variant);
 
-  ASSERT_STR_EQ("zzz", event->feature_flags[1].name);
-  ASSERT_EQ(NULL, event->feature_flags[1].variant);
+  ASSERT_STR_EQ("demo_mode", event->feature_flags[1].name);
+  ASSERT_STR_EQ("yes", event->feature_flags[1].variant);
 
-  ASSERT_STR_EQ("demo_mode", event->feature_flags[2].name);
-  ASSERT_STR_EQ("yes", event->feature_flags[2].variant);
+  ASSERT_STR_EQ("zzz", event->feature_flags[2].name);
+  ASSERT_EQ(NULL, event->feature_flags[2].variant);
 
   bsg_free_feature_flags(event);
   free(event);