From cf913b41c6f3e3d46eb654feb7b43a48dd141d97 Mon Sep 17 00:00:00 2001
From: Christian Buttner <christian@cbuttner.de>
Date: Fri, 18 Jul 2025 15:54:07 +0200
Subject: [PATCH] Fix `Formatter.print` returning incorrect size (#2306)

* Fix `Formatter.print` returning incorrect size
---
 lib/std/io/formatter.c3                                   | 3 +--
 lib/std/io/formatter_private.c3                           | 1 -
 releasenotes.md                                           | 2 ++
 test/test_suite/struct/init_cont_struct_array_locally.c3t | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/std/io/formatter.c3 b/lib/std/io/formatter.c3
index db21b9bca..4c89d5ee1 100644
--- a/lib/std/io/formatter.c3
+++ b/lib/std/io/formatter.c3
@@ -69,7 +69,6 @@ struct Formatter
 		PrintFlags flags;
 		uint width;
 		uint prec;
-		usz idx;
 		fault first_fault;
 	}
 }
@@ -571,5 +570,5 @@ fn usz? Formatter.print(&self, String str)
 		self.out_fn = &out_null_fn;
 	}
 	foreach (c : str) self.out(c)!;
-	return self.idx;
+	return str.len;
 }
diff --git a/lib/std/io/formatter_private.c3 b/lib/std/io/formatter_private.c3
index 5291355f3..1080f447c 100644
--- a/lib/std/io/formatter_private.c3
+++ b/lib/std/io/formatter_private.c3
@@ -660,7 +660,6 @@ fn usz? Formatter.out_char(&self, any arg) @private
 fn usz? Formatter.out_reverse(&self, char[] buf) @private
 {
 	usz n;
-	usz buffer_start_idx = self.idx;
 	usz len = buf.len;
 	// pad spaces up to given width
 	if (!self.flags.zeropad && !self.flags.left)
diff --git a/releasenotes.md b/releasenotes.md
index 2ab8517be..ddd4cdda0 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -59,6 +59,7 @@
 - Segfault when failing to cast subexpression to 'isz' in pointer subtraction #2305.
 - Fix unexpected display of macro definition when passing a poisoned expression #2305.
 - `@links` on macros would not be added to calling functions.
+- Fix `Formatter.print` returning incorrect size.
 
 ### Stdlib changes
 - Improve contract for readline. #2280
@@ -66,6 +67,7 @@
 - Added string::bformat.
 - Virtual memory library.
 - New virtual emory arena allocator.
+- Added `WString.len`.
 
 ## 0.7.3 Change list
 
diff --git a/test/test_suite/struct/init_cont_struct_array_locally.c3t b/test/test_suite/struct/init_cont_struct_array_locally.c3t
index 66282d803..5967404cb 100644
--- a/test/test_suite/struct/init_cont_struct_array_locally.c3t
+++ b/test/test_suite/struct/init_cont_struct_array_locally.c3t
@@ -49,7 +49,7 @@ entry:
   %0 = call ptr @std.io.stdout()
   call void @llvm.memcpy.p0.p0.i32(ptr align 1 %x1, ptr align 1 %x, i32 2, i1 false)
   call void @llvm.memcpy.p0.p0.i32(ptr align 1 %x2, ptr align 1 %x1, i32 2, i1 false)
-  call void @llvm.memset.p0.i64(ptr align 8 %formatter, i8 0, i64 48, i1 false)
+  call void @llvm.memset.p0.i64(ptr align 8 %formatter, i8 0, i64 40, i1 false)
   %1 = insertvalue %any undef, ptr %0, 0
   %2 = insertvalue %any %1, i64 ptrtoint (ptr @"$ct.std.io.File" to i64), 1
   store %any %2, ptr %taddr, align 8