Correctly handle nested or-patterns in column-wise analyses

2 files changed, 7 insertions, 1 deletions

diff --git a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
index 25e0f3ceaa4..59f0849d08b 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/usefulness.rs
@@ -931,7 +931,7 @@ impl<'p, 'tcx> PatternColumn<'p, 'tcx> {
             let specialized = pat.specialize(pcx, &ctor);
             for (subpat, column) in specialized.iter().zip(&mut specialized_columns) {
                 if subpat.is_or_pat() {
-                    column.patterns.extend(subpat.iter_fields())
+                    column.patterns.extend(subpat.flatten_or_pat())
                 } else {
                     column.patterns.push(subpat)
                 }
diff --git a/tests/ui/or-patterns/exhaustiveness-pass.rs b/tests/ui/or-patterns/exhaustiveness-pass.rs
index e8c8a0e7ba5..428b9a19fe6 100644
--- a/tests/ui/or-patterns/exhaustiveness-pass.rs
+++ b/tests/ui/or-patterns/exhaustiveness-pass.rs
@@ -35,4 +35,10 @@ fn main() {
         ((0, 0) | (1, 0),) => {}
         _ => {}
     }
+
+    // This one caused ICE https://github.com/rust-lang/rust/issues/117378
+    match (0u8, 0) {
+        (x @ 0 | x @ (1 | 2), _) => {}
+        (3.., _) => {}
+    }
 }