Small, all zero files are replaced by *silence

src/sfizz/FilePool.cpp

@@ -355,7 +355,6 @@ sfz::FileDataHolder sfz::FilePool::loadFile(const FileId& fileId) noexcept
             *fileInformation
         });
         insertedPair.first->second.status = FileData::Status::Preloaded;
-        ASSERT(insertedPair.second);
         return { &insertedPair.first->second };
     }
 }

src/sfizz/Synth.cpp

@@ -595,8 +595,24 @@ void Synth::Impl::finalizeSfzLoad()
                 continue;
             }
 
-            region.hasWavetableSample = fileInformation->wavetable ||
-                fileInformation->end < config::wavetableMaxFrames;
+            region.hasWavetableSample = fileInformation->wavetable.has_value();
+
+            if (fileInformation->end < config::wavetableMaxFrames) {
+                auto sample = resources_.filePool.loadFile(*region.sampleId);
+                bool allZeros = true;
+                int numChannels = sample->information.numChannels;
+                for (int i = 0; i < numChannels; ++i) {
+                    allZeros &= allWithin(sample->preloadedData.getConstSpan(i),
+                        -config::virtuallyZero, config::virtuallyZero);
+                }
+
+                if (allZeros) {
+                    region.sampleId.reset(new FileId("*silence"));
+                    region.hasWavetableSample = false;
+                } else {
+                    region.hasWavetableSample |= true;
+                }
+            }
         }
 
         if (!region.isOscillator()) {

tests/SynthT.cpp

@@ -1811,3 +1811,20 @@ TEST_CASE("[Keyswitches] Trigger from aftertouch extended CC")
     synth.renderBlock(buffer);
     REQUIRE(synth.getNumActiveVoices() == 2);
 }
+
+TEST_CASE("[Synth] Short empty files are turned into *silence")
+{
+    sfz::Synth synth;
+    std::vector<std::string> messageList;
+    sfz::Client client(&messageList);
+    client.setReceiveCallback(&simpleMessageReceiver);
+    sfz::AudioBuffer<float> buffer { 2, static_cast<unsigned>(synth.getSamplesPerBlock()) };
+    synth.loadSfzString(fs::current_path() / "tests/TestFiles/aftertouch_trigger.sfz", R"(
+        <region> sample=silence.wav
+    )");
+    synth.dispatchMessage(client, 0, "/region0/sample", "", nullptr);
+    std::vector<std::string> expected {
+        "/region0/sample,s : { *silence }",
+    };
+    REQUIRE(messageList == expected);
+}