From 803433a161d0804ebf55eabb97171566fdc4e825 Mon Sep 17 00:00:00 2001
From: Viraat Das <viraat.laldas@gmail.com>
Date: Thu, 4 Jun 2026 22:25:08 -0700
Subject: [PATCH] Apply insensitive key name when deleting a key

Fixes #340.

`Section.DeleteKey` did not honour `Insensitive`/`InsensitiveKeys`, so a key loaded case-insensitively could not be deleted by a differently-cased name and `DeleteKey` became a no-op. Lower-case the name the same way the rest of the section does before matching. Added a test that deletes a key under `Insensitive: true`.
---
 section.go      |  4 ++++
 section_test.go | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/section.go b/section.go
index a3615d8..2b1e2b9 100644
--- a/section.go
+++ b/section.go
@@ -226,6 +226,10 @@ func (s *Section) KeysHash() map[string]string {
 
 // DeleteKey deletes a key from section.
 func (s *Section) DeleteKey(name string) {
+	if s.f.options.Insensitive || s.f.options.InsensitiveKeys {
+		name = strings.ToLower(name)
+	}
+
 	if s.f.BlockMode {
 		s.f.lock.Lock()
 		defer s.f.lock.Unlock()
diff --git a/section_test.go b/section_test.go
index 09ed366..2728948 100644
--- a/section_test.go
+++ b/section_test.go
@@ -312,4 +312,14 @@ func TestSection_DeleteKey(t *testing.T) {
 		f.Section("").DeleteKey("NAME")
 		assert.False(t, f.Section("").HasKey("NAME"))
 	})
+
+	t.Run("delete a key with insensitive names", func(t *testing.T) {
+		f, err := LoadSources(LoadOptions{Insensitive: true}, []byte("TestKey = value"))
+		require.NoError(t, err)
+		require.NotNil(t, f)
+
+		assert.True(t, f.Section("").HasKey("TestKey"))
+		f.Section("").DeleteKey("TestKey")
+		assert.False(t, f.Section("").HasKey("TestKey"))
+	})
 }