Commit f96748ebc1

@@ -11995,10 +11995,18 @@ fn zirArrayCat(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Ai
             const element_vals = try sema.arena.alloc(Value, final_len_including_sent);
             var elem_i: usize = 0;
             while (elem_i < lhs_len) : (elem_i += 1) {
-                element_vals[elem_i] = try lhs_sub_val.elemValue(sema.mod, sema.arena, elem_i);
+                const elem_val = try lhs_sub_val.elemValue(sema.mod, sema.arena, elem_i);
+                const elem_val_inst = try sema.addConstant(lhs_info.elem_type, elem_val);
+                const coerced_elem_val_inst = try sema.coerce(block, resolved_elem_ty, elem_val_inst, .unneeded);
+                const coereced_elem_val = try sema.resolveConstMaybeUndefVal(block, .unneeded, coerced_elem_val_inst, "");
+                element_vals[elem_i] = coereced_elem_val;
             }
             while (elem_i < result_len) : (elem_i += 1) {
-                element_vals[elem_i] = try rhs_sub_val.elemValue(sema.mod, sema.arena, elem_i - lhs_len);
+                const elem_val = try rhs_sub_val.elemValue(sema.mod, sema.arena, elem_i - lhs_len);
+                const elem_val_inst = try sema.addConstant(lhs_info.elem_type, elem_val);
+                const coerced_elem_val_inst = try sema.coerce(block, resolved_elem_ty, elem_val_inst, .unneeded);
+                const coereced_elem_val = try sema.resolveConstMaybeUndefVal(block, .unneeded, coerced_elem_val_inst, "");
+                element_vals[elem_i] = coereced_elem_val;
             }
             if (res_sent_val) |sent_val| {
                 element_vals[result_len] = sent_val;

@@ -1488,3 +1488,14 @@ test "x or true is comptime-known true" {
     }
     try expect(T.x == 3);
 }
+
+test "non-optional and optional array elements concatenated" {
+    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_wasm) return error.SkipZigTest; // TODO
+
+    const array = [1]u8{'A'} ++ [1]?u8{null};
+    var index: usize = 0;
+    try expect(array[index].? == 'A');
+}