From f8a79c16e0f1b50cf3c111e83c5e15cdd05b1616 Mon Sep 17 00:00:00 2001
From: Volker Berlin <volker.berlin@googlemail.com>
Date: Fri, 29 Jul 2022 22:15:39 +0200
Subject: [PATCH] Fix complex catch blocks with multiple catch

---
 .../jwebassembly/module/BranchManager.java          |  6 +++++-
 .../jwebassembly/runtime/Exceptions.java            | 13 +++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/de/inetsoftware/jwebassembly/module/BranchManager.java b/src/de/inetsoftware/jwebassembly/module/BranchManager.java
index 4814347..478e5f9 100644
--- a/src/de/inetsoftware/jwebassembly/module/BranchManager.java
+++ b/src/de/inetsoftware/jwebassembly/module/BranchManager.java
@@ -1251,10 +1251,11 @@ class BranchManager {
 
         // Create a block/end structure for every CATCH without the first CATCH
         BranchNode node = catchNode;
+        TryCatchFinally tryCurrent = tryCatch;
         for( int i = catches.size()-1; i > 0; i-- ) {
             TryCatchFinally tryCat = catches.get( i );
 
-            if( tryCatch.getHandler() == tryCat.getHandler() ) {
+            if( tryCurrent.getHandler() == tryCat.getHandler() ) {
                 // multiple exception in catch block like "catch ( ArrayIndexOutOfBoundsException | IllegalArgumentException ex )"
                 continue;
             }
@@ -1277,7 +1278,10 @@ class BranchManager {
             node = block;
 
             int instrPos = findIdxOfCodePos( tryCat.getHandler() ) + 1;
+            assert (instructions.get( instrPos ) instanceof WasmLoadStoreInstruction) && ((WasmLoadStoreInstruction)instructions.get( instrPos )).getOperator() == VariableOperator.set : "Catch block does not start with astore instruction " + instructions.get( instrPos );
             instructions.remove( instrPos ); // every catch block store the exception from the stack but in WASM we can do this only once for all exceptions
+
+            tryCurrent = tryCat;
         }
 
         // calculate branch operations inside the CATCH/FINALLY blocks
diff --git a/test/de/inetsoftware/jwebassembly/runtime/Exceptions.java b/test/de/inetsoftware/jwebassembly/runtime/Exceptions.java
index 0b27b1f..918823d 100644
--- a/test/de/inetsoftware/jwebassembly/runtime/Exceptions.java
+++ b/test/de/inetsoftware/jwebassembly/runtime/Exceptions.java
@@ -57,6 +57,7 @@ public class Exceptions extends AbstractBaseTest {
             addParam( list, script, "emptyCatch" );
             addParam( list, script, "multiCatch" );
             addParam( list, script, "multiCatch2" );
+            addParam( list, script, "multiCatch3" );
             addParam( list, script, "serialCatch" );
             addParam( list, script, "tryReturn" );
             addParam( list, script, "whileTrueTryFinally" );
@@ -241,6 +242,18 @@ public class Exceptions extends AbstractBaseTest {
             return r;
         }
 
+        @Export
+        public static int multiCatch3() throws Throwable {
+            try {
+                new Throwable();
+                return 42;
+            } catch( IllegalStateException x ) {
+            } catch( IllegalArgumentException | NullPointerException x ) {
+                throw new Throwable( x );
+            }
+            return 13;
+        }
+
         @Export
         static int serialCatch() {
             int r = 42;