From 10b817df2e89460483a1b643bee7153dfd24ced7 Mon Sep 17 00:00:00 2001
From: "Alexander \"Arav\" Andreev" <me@arav.su>
Date: Sun, 1 Oct 2023 06:36:47 +0400
Subject: [PATCH] In oggtag handle a case when tag name are in upper case.

---
 pkg/oggtag/oggtag.go | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/pkg/oggtag/oggtag.go b/pkg/oggtag/oggtag.go
index 7fcf8aa..47d344a 100644
--- a/pkg/oggtag/oggtag.go
+++ b/pkg/oggtag/oggtag.go
@@ -6,6 +6,7 @@ for certain tag names ending with an = character, e.g. artist= and title=.
 
 import (
 	"bytes"
+	"strings"
 )
 
 // OggGetTag is searching for a certain tag in a given buffer buf and returns
@@ -15,7 +16,14 @@ import (
 // looking for a certain tag preceded with three zero bytes and ends with
 // an = character.
 func OggGetTag(buf []byte, tag string) string {
-	tagIdx := bytes.Index(buf, append([]byte{0, 0, 0}, (tag+"=")...)) + 3
+	tagIdx := bytes.Index(buf, append([]byte{0, 0, 0}, (tag+"=")...))
+	if tagIdx == -1 {
+		tagIdx = bytes.Index(buf, append([]byte{0, 0, 0}, (strings.ToUpper(tag)+"=")...))
+		if tagIdx == -1 {
+			return ""
+		}
+	}
+	tagIdx += 3
 	tagNameLen := len(tag) + 1
 	valStart := tagIdx + tagNameLen
 	valLen := int(buf[tagIdx-4]) - tagNameLen