From 341a70bd5dbfd0573e4eaa8fd8cb64d805626359 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Thu, 20 Feb 2025 03:44:22 +0100
Subject: [PATCH] Implicitly unwrapped optional value in defer incorrectly
 copied #1982.

---
 releasenotes.md                               |  1 +
 src/compiler/copying.c                        | 15 ++++++
 test/src/test_suite_runner.c3                 |  2 +-
 .../test_suite/defer/defer_with_unwrapped.c3t | 53 +++++++++++++++++++
 4 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 test/test_suite/defer/defer_with_unwrapped.c3t

diff --git a/releasenotes.md b/releasenotes.md
index 9d9aa5f2e..227a40c49 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -14,6 +14,7 @@
 - Test runner with tracking allocator assertion at failed test #1963
 - Test runner with tracking allocator didn't properly handle teardown_fn
 - Correctly give an error if a character literal contains a line break.
+- Implicitly unwrapped optional value in defer incorrectly copied #1982.
 
 ### Stdlib changes
 
diff --git a/src/compiler/copying.c b/src/compiler/copying.c
index d8a4e9c41..e07f6e2a5 100644
--- a/src/compiler/copying.c
+++ b/src/compiler/copying.c
@@ -399,8 +399,23 @@ Expr *copy_expr(CopyStruct *c, Expr *source_expr)
 			MACRO_COPY_EXPR_LIST(expr->catch_expr.exprs);
 			return expr;
 		case EXPR_IDENTIFIER:
+		{
+			Decl *var = expr->ident_expr;
+			// In the case we have an unwrapped alias, we need to create it.
+			if (var->decl_kind == DECL_VAR)
+			{
+				switch (var->var.kind)
+				{
+					case VARDECL_UNWRAPPED:
+					case VARDECL_REWRAPPED:
+						expr->ident_expr = copy_decl(c, var);
+						return expr;
+					default: break;
+				}
+			}
 			fixup_decl(c, &expr->ident_expr);
 			return expr;
+		}
 		case EXPR_UNRESOLVED_IDENTIFIER:
 		case EXPR_CT_IDENT:
 		case EXPR_HASH_IDENT:
diff --git a/test/src/test_suite_runner.c3 b/test/src/test_suite_runner.c3
index 3aa70aa37..80db7501f 100644
--- a/test/src/test_suite_runner.c3
+++ b/test/src/test_suite_runner.c3
@@ -58,7 +58,7 @@ fn void main(String[] args)
 
 	// Print the test result
 	io::printfn("Found %d tests: %.1f%% (%d / %d) passed (%d skipped).",
-        test_count, 100 * success_count / math::max(1, test_count - skip_count),
+        test_count, (100.0 * success_count) / math::max(1, test_count - skip_count),
         success_count, test_count - skip_count, skip_count);
     libc::exit(success_count == test_count - skip_count ? 0 :  1);
 }
diff --git a/test/test_suite/defer/defer_with_unwrapped.c3t b/test/test_suite/defer/defer_with_unwrapped.c3t
new file mode 100644
index 000000000..365c86a9a
--- /dev/null
+++ b/test/test_suite/defer/defer_with_unwrapped.c3t
@@ -0,0 +1,53 @@
+// #target: macos-x64
+module test;
+import std::io;
+// Issue 1982
+fn int main()
+{
+	defer
+	{
+		int! x = 1;
+		if (catch err = x) unreachable();
+		int y = x;
+	}
+	return 0;
+}
+/* #expect: test.ll
+
+define i32 @main() #0 {
+entry:
+  %x = alloca i32, align 4
+  %x.f = alloca i64, align 8
+  %err = alloca i64, align 8
+  %y = alloca i32, align 4
+  store i32 1, ptr %x, align 4
+  store i64 0, ptr %x.f, align 8
+  br label %testblock
+
+testblock:                                        ; preds = %entry
+  %optval = load i64, ptr %x.f, align 8
+  %not_err = icmp eq i64 %optval, 0
+  %0 = call i1 @llvm.expect.i1(i1 %not_err, i1 true)
+  br i1 %0, label %after_check, label %assign_optional
+
+assign_optional:                                  ; preds = %testblock
+  store i64 %optval, ptr %err, align 8
+  br label %end_block
+
+after_check:                                      ; preds = %testblock
+  store i64 0, ptr %err, align 8
+  br label %end_block
+
+end_block:                                        ; preds = %after_check, %assign_optional
+  %1 = load i64, ptr %err, align 8
+  %i2b = icmp ne i64 %1, 0
+  br i1 %i2b, label %if.then, label %if.exit
+
+if.then:                                          ; preds = %end_block
+  unreachable
+
+if.exit:                                          ; preds = %end_block
+  %2 = load i32, ptr %x, align 4
+  store i32 %2, ptr %y, align 4
+  ret i32 0
+}