LV2: check feature arrays for duplicated entries (which is a host bug)

- rncbc/qtractor#427 Signed-off-by: Stefan Westerfeld <[email protected]>
swesterfeld · Dec 16, 2023 · ad351b0 · ad351b0
1 parent 923d71c
commit ad351b0
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Showing 3 changed files with 26 additions and 0 deletions.
diff --git a/lv2/smlv2common.hh b/lv2/smlv2common.hh
@@ -33,6 +33,7 @@
 #endif
 
 #include <string>
+#include <set>
 
 #define SPECTMORPH_URI      "http://spectmorph.org/plugins/spectmorph"
 #define SPECTMORPH_UI_URI   SPECTMORPH_URI "#ui"
@@ -102,6 +103,23 @@ public:
     uris.time_speed         = map->map (map->handle, LV2_TIME__speed);
     uris.time_Position      = map->map (map->handle, LV2_TIME__Position);
   }
+  static void
+  detect_repeated_features (const LV2_Feature* const* features)
+  {
+    std::set<std::string> has_feature;
+    for (int i = 0; features[i]; i++)
+      {
+        if (has_feature.count (features[i]->URI))
+          {
+            fprintf (stderr, "SpectMorph: LV2 Plugin: feature '%s' is provided more than once by host\n", features[i]->URI);
+            fprintf (stderr, "  -> this is a host bug, possibly related to https://github.com/rncbc/qtractor/issues/427\n");
+          }
+        else
+          {
+            has_feature.insert (features[i]->URI);
+          }
+      }
+  }
 };
 
 }

diff --git a/lv2/smlv2plugin.cc b/lv2/smlv2plugin.cc
@@ -75,6 +75,8 @@ instantiate (const LV2_Descriptor*     descriptor,
 
   LV2Plugin *self = new LV2Plugin (rate);
 
+  LV2Common::detect_repeated_features (features);
+
   LV2_URID_Map* map = NULL;
   for (int i = 0; features[i]; i++)
     {
@@ -285,6 +287,8 @@ save(LV2_Handle                instance,
 {
   LV2Plugin* self = static_cast <LV2Plugin *> (instance);
 
+  LV2Common::detect_repeated_features (features);
+
   LV2_State_Map_Path *map_path = nullptr;
 #ifdef LV2_STATE__freePath
   LV2_State_Free_Path *free_path = nullptr;
@@ -370,6 +374,8 @@ restore(LV2_Handle                  instance,
   uint32_t    valflags;
   const void* value;
 
+  LV2Common::detect_repeated_features (features);
+
   LV2_State_Map_Path *map_path = nullptr;
 #ifdef LV2_STATE__freePath
   LV2_State_Free_Path *free_path = nullptr;

diff --git a/lv2/smlv2ui.cc b/lv2/smlv2ui.cc
@@ -64,6 +64,8 @@ instantiate(const LV2UI_Descriptor*   descriptor,
 
   LV2_DEBUG ("instantiate called for ui\n");
 
+  LV2Common::detect_repeated_features (features);
+
   LV2Plugin *plugin = nullptr;
   PuglNativeWindow parent_win_id = 0;
   LV2_URID_Map* map    = nullptr;