From 1eae14a3befb97db5bd8f95427b007fc5490b8a4 Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Fri, 17 Oct 2025 23:32:28 +0800
Subject: [PATCH] fixes #25226; VM repr raises RangeDefect for long string
 under refc (#25230)

fixes #25226

`int16` seems to be too small for a reasonable VM program
---
 compiler/renderer.nim | 4 ++--
 tests/vm/tmisc_vm.nim | 7 +++++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/compiler/renderer.nim b/compiler/renderer.nim
index 1887e5a1a9..19eb45be8d 100644
--- a/compiler/renderer.nim
+++ b/compiler/renderer.nim
@@ -30,7 +30,7 @@ type
   TRenderFlags* = set[TRenderFlag]
   TRenderTok* = object
     kind*: TokType
-    length*: int16
+    length*: int32
     sym*: PSym
 
   Section = enum
@@ -154,7 +154,7 @@ proc initSrcGen(renderFlags: TRenderFlags; config: ConfigRef): TSrcGen =
                    )
 
 proc addTok(g: var TSrcGen, kind: TokType, s: string; sym: PSym = nil) =
-  g.tokens.add TRenderTok(kind: kind, length: int16(s.len), sym: sym)
+  g.tokens.add TRenderTok(kind: kind, length: int32(s.len), sym: sym)
   g.buf.add(s)
   if kind != tkSpaces:
     inc g.col, s.len
diff --git a/tests/vm/tmisc_vm.nim b/tests/vm/tmisc_vm.nim
index 6a0c0c33fb..56f2536376 100644
--- a/tests/vm/tmisc_vm.nim
+++ b/tests/vm/tmisc_vm.nim
@@ -479,3 +479,10 @@ static:
 
 xxx()
 
+
+static:
+  var foo: string
+  for _ in 0 ..< 100_000:
+    foo.add 'a'
+  doAssert repr(foo).len == 100_002
+