3 files changed, 44 insertions, 2 deletions
diff --git a/src/passes/RemoveUnusedBrs.cpp b/src/passes/RemoveUnusedBrs.cpp
index e627ce138..e307ec414 100644
--- a/src/passes/RemoveUnusedBrs.cpp
+++ b/src/passes/RemoveUnusedBrs.cpp
@@ -482,9 +482,11 @@ struct RemoveUnusedBrs : public WalkerPass<PostWalker<RemoveUnusedBrs>> {
             // a "selectified" condition that executes both.
             for (Index i = 0; i < list.size() - 1; i++) {
               auto* br1 = list[i]->dynCast<Break>();
-              if (!br1 || !br1->condition) continue;
+              // avoid unreachable brs, as they are dead code anyhow, and after merging
+              // them the outer scope could need type changes
+              if (!br1 || !br1->condition || br1->type == unreachable) continue;
               auto* br2 = list[i + 1]->dynCast<Break>();
-              if (!br2 || !br2->condition) continue;
+              if (!br2 || !br2->condition || br2->type == unreachable) continue;
               if (br1->name == br2->name) {
                 assert(!br1->value && !br2->value);
                 if (!EffectAnalyzer(passOptions, br2->condition).hasSideEffects()) {
diff --git a/test/passes/remove-unused-brs_shrink-level=1.txt b/test/passes/remove-unused-brs_shrink-level=1.txt
index a26f4ebf4..fb739356c 100644
--- a/test/passes/remove-unused-brs_shrink-level=1.txt
+++ b/test/passes/remove-unused-brs_shrink-level=1.txt
@@ -139,4 +139,24 @@
    )
   )
  )
+ (func $br-if-unreachable-pair (type $1)
+  (block $label$14
+   (br_if $label$14
+    (unreachable)
+   )
+   (br_if $label$14
+    (i32.const 0)
+   )
+  )
+ )
+ (func $br-if-unreachable-pair2 (type $1)
+  (block $label$14
+   (br_if $label$14
+    (i32.const 0)
+   )
+   (br_if $label$14
+    (unreachable)
+   )
+  )
+ )
 )
diff --git a/test/passes/remove-unused-brs_shrink-level=1.wast b/test/passes/remove-unused-brs_shrink-level=1.wast
index 88977be9e..11510dea7 100644
--- a/test/passes/remove-unused-brs_shrink-level=1.wast
+++ b/test/passes/remove-unused-brs_shrink-level=1.wast
@@ -93,5 +93,25 @@
     )
    )
   )
+  (func $br-if-unreachable-pair
+   (block $label$14
+    (br_if $label$14
+     (unreachable)
+    )
+    (br_if $label$14
+     (i32.const 0)
+    )
+   )
+  )
+  (func $br-if-unreachable-pair2
+   (block $label$14
+    (br_if $label$14
+     (i32.const 0)
+    )
+    (br_if $label$14
+     (unreachable)
+    )
+   )
+  )
 )