config: Fix duplicate header detection for all case variants (#2810)

dgl · SuperQ · web-flow · commit 162ee9b48e37 · 2025-10-31T15:14:48.000+01:00
strings.Title only uppercases characters, it does not fully
canonicalise.

Signed-off-by: David Leadbeater &lt;dgl@dgl.cx&gt;
Co-authored-by: Ben Kochie &lt;superq@gmail.com&gt;
diff --git a/config/notifiers_test.go b/config/notifiers_test.go
@@ -46,7 +46,7 @@ func TestEmailHeadersCollision(t *testing.T) {
 to: 'to@email.com'
 headers:
   Subject: 'Alert'
-  subject: 'New Alert'
+  sUbject: 'New Alert'
 `
 	var cfg EmailConfig
 	err := yaml.UnmarshalStrict([]byte(in), &cfg)

Original file line number	Diff line number	Diff line change
`@@ -46,7 +46,7 @@ func TestEmailHeadersCollision(t *testing.T) {`
`46`	`46`	`to: '[email protected]'`
`47`	`47`	`headers:`
`48`	`48`	`Subject: 'Alert'`
`49`		`- subject: 'New Alert'`
	`49`	`+ sUbject: 'New Alert'`
`50`	`50`	`
`51`	`51`	`var cfg EmailConfig`
`52`	`52`	`err := yaml.UnmarshalStrict([]byte(in), &cfg)`