fix memory growing for empty data segments

src/Language/Wasm/Interpreter.hs

@@ -316,6 +316,7 @@ initialize inst Module {elems, datas, start} store = do
             return $ st { tableInstances = tableInstances st Vector.// [(idx, table)] }
 
         fitOrGrowMemory :: Address -> Store -> Int -> IO MemoryInstance
+        fitOrGrowMemory idx st 0 = return $ memInstances st ! idx
         fitOrGrowMemory idx st last = do
             let m@(MemoryInstance mem maxLen) = memInstances st ! idx
             let len = IOVector.length mem
@@ -329,7 +330,7 @@ initialize inst Module {elems, datas, start} store = do
                 Nothing -> increased
                 Just max ->
                     let maxInBytes = max * pageSize in
-                    if maxInBytes <= last
+                    if maxInBytes < last
                     then error $ "Max memory length reached. Max " ++ show max ++ "(" ++ show maxInBytes ++ "b), but requested " ++ show last
                     else increased
 

tests/Test.hs

@@ -34,7 +34,7 @@ compile file = do
 main :: IO ()
 main = do
   files <- Directory.listDirectory "tests/samples"
-  -- let files = ["func.wast"]
+  -- let files = ["memory.wast"]
   scriptTestCases <- (`mapM` files) $ \file -> do
     content <- LBS.readFile $ "tests/samples/" ++ file
     let Right script = Parser.parseScript <$> Lexer.scanner content