From 4e1b46a958c2d363119c69a90810168055119a52 Mon Sep 17 00:00:00 2001
From: Jennifer Thakar <jathak@google.com>
Date: Wed, 12 Jan 2022 14:28:14 -0800
Subject: [PATCH] Fix string.insert with negative indices

---
 CHANGELOG.md                  | 6 +++++-
 lib/src/functions/string.dart | 2 +-
 pubspec.yaml                  | 2 +-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ca3268343..ded183b89 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.48.1
+
+* Fix a bug in `string.insert` with certain negative indices.
+
 ## 1.48.0
 
 ### JS API
@@ -23,7 +27,7 @@
 
 * **Potentially breaking bug fix:** Match the specification of the new JS API by
   passing `undefined` rather than `null` to `Logger.warn()` for an unset `span`.
-  
+
 #### TypeScript Declarations
 
 * Add a declaration for the `LegacyPluginThis.options.context` field.
diff --git a/lib/src/functions/string.dart b/lib/src/functions/string.dart
index ba33bc402..04a441e95 100644
--- a/lib/src/functions/string.dart
+++ b/lib/src/functions/string.dart
@@ -66,7 +66,7 @@ final _insert = _function("insert", r"$string, $insert, $index", (arguments) {
   if (indexInt < 0) {
     // +1 because negative indexes start counting from -1 rather than 0, and
     // another +1 because we want to insert *after* that index.
-    indexInt = string.sassLength + indexInt + 2;
+    indexInt = math.max(string.sassLength + indexInt + 2, 0);
   }
 
   var codepointIndex = _codepointForIndex(indexInt, string.sassLength);
diff --git a/pubspec.yaml b/pubspec.yaml
index d82e7d9d0..4e83b80a6 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: sass
-version: 1.48.0
+version: 1.48.1-dev
 description: A Sass implementation in Dart.
 homepage: https://github.com/sass/dart-sass