From b80c354e8b9532d7deec463625f129d106f8f51c Mon Sep 17 00:00:00 2001
From: Takafumi ONAKA <takafumi.onaka@gmail.com>
Date: Sun, 9 Nov 2025 14:06:21 +0900
Subject: [PATCH 1/3] Fix ANSI carry-over indexes when wrapping

Fixes an IndexError raised when an ANSI code starts at the end of a wrapped line and carries over to a shorter next line.
The carry-over kept the original column index, so insert_ansi tried to insert beyond the new string length.

Normalize carried-over ANSI entries to [code, 0] so they always reapply at the beginning of the next line.
---
 lib/strings/wrap.rb                | 2 +-
 spec/unit/wrap/insert_ansi_spec.rb | 2 +-
 spec/unit/wrap/wrap_spec.rb        | 8 ++++++++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/lib/strings/wrap.rb b/lib/strings/wrap.rb
index 7dbda07..0e204fe 100644
--- a/lib/strings/wrap.rb
+++ b/lib/strings/wrap.rb
@@ -146,7 +146,7 @@ def insert_ansi(string, ansi_stack = [])
           next
         elsif !matched_reset # ansi without reset
           matched_reset = false
-          new_stack << ansi # keep the ansi
+          new_stack.unshift([ansi[0], 0]) # carry over ANSI to the start of next line preserving order
           next if ansi[1] == length
           if output.end_with?(NEWLINE)
             output.insert(-2, ansi_reset)
diff --git a/spec/unit/wrap/insert_ansi_spec.rb b/spec/unit/wrap/insert_ansi_spec.rb
index 4497da3..15b84d2 100644
--- a/spec/unit/wrap/insert_ansi_spec.rb
+++ b/spec/unit/wrap/insert_ansi_spec.rb
@@ -60,6 +60,6 @@
     val = Strings::Wrap.insert_ansi(text, stack)
 
     expect(val).to eq("\e[32mone\e[0m")
-    expect(stack).to eq([["\e[33m", 3]])
+    expect(stack).to eq([["\e[33m", 0]])
   end
 end
diff --git a/spec/unit/wrap/wrap_spec.rb b/spec/unit/wrap/wrap_spec.rb
index 1fdcc96..bd11584 100644
--- a/spec/unit/wrap/wrap_spec.rb
+++ b/spec/unit/wrap/wrap_spec.rb
@@ -178,6 +178,14 @@
       ].join("\n"))
     end
 
+    it "wraps when ANSI start carries over to the next line" do
+      text = "aaaaaaa \e[31mbb"
+      expect(Strings::Wrap.wrap(text, 8)).to eq([
+        "aaaaaaa ",
+        "\e[31mbb\e[0m"
+      ].join("\n"))
+    end
+
     it "applies ANSI codes when below wrap width" do
       str = "\e[32mone\e[0m\e[33mtwo\e[0m"
 

From 6db3f382a3fb593437199d0805cb5cf3f7061e4a Mon Sep 17 00:00:00 2001
From: Takafumi ONAKA <takafumi.onaka@gmail.com>
Date: Sun, 9 Nov 2025 15:59:48 +0900
Subject: [PATCH 2/3] Add stacked ANSI wrap reapply order test

---
 spec/unit/wrap/wrap_spec.rb | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/spec/unit/wrap/wrap_spec.rb b/spec/unit/wrap/wrap_spec.rb
index bd11584..fcf89e4 100644
--- a/spec/unit/wrap/wrap_spec.rb
+++ b/spec/unit/wrap/wrap_spec.rb
@@ -186,6 +186,15 @@
       ].join("\n"))
     end
 
+    it "applies stacked ANSI colors after wrapping" do
+      text = "aaaa \e[31mbbbb \e[32mcc"
+      expect(Strings::Wrap.wrap(text, 5)).to eq([
+        "aaaa ",
+        "\e[31mbbbb \e[0m",
+        "\e[31m\e[32mcc\e[0m\e[0m"
+      ].join("\n"))
+    end
+
     it "applies ANSI codes when below wrap width" do
       str = "\e[32mone\e[0m\e[33mtwo\e[0m"
 

From 803d27d9345df27f77a4c2dabb74f21875fd3e9c Mon Sep 17 00:00:00 2001
From: Takafumi ONAKA <takafumi.onaka@gmail.com>
Date: Sun, 9 Nov 2025 17:01:28 +0900
Subject: [PATCH 3/3] Add CHANGELOG

---
 CHANGELOG.md | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8d48391..ff817f7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Change log
 
+## Unreleased
+
+### Fixed
+
+* Fix IndexError in `Strings::Wrap.wrap` and correct ANSI color insertion on wrap (@onk)
+
 ## [v0.2.1] - 2021-03-09
 
 ### Changed