From 2fda0a505d05ee440c8733a67037336e29a7b6d7 Mon Sep 17 00:00:00 2001
From: Martchus <martchus@gmx.net>
Date: Sun, 8 Aug 2021 01:20:39 +0200
Subject: [PATCH] Prevent showing warning about encoding wrongly when making
 ID3v1 fields

Due to the fallthrough the warning would be printed in any case when using
UTF-8 and not only if the BOM is actually written (as there are non-ASCII
characters). This problem became apparent when using the tageditor's CLI
with `--id3-init-on-create` to create an ID3v1 tag from ID3v2. Of course it
doesn't help if there are actually non-ASCII characters present.
---
 id3/id3v1tag.cpp | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/id3/id3v1tag.cpp b/id3/id3v1tag.cpp
index 0cb9bd1..25ef952 100644
--- a/id3/id3v1tag.cpp
+++ b/id3/id3v1tag.cpp
@@ -313,12 +313,12 @@ void Id3v1Tag::writeValue(const TagValue &value, size_t length, char *buffer, os
     // handle encoding
     auto *valueStart = buffer;
     auto valueLength = length;
+    auto hasProblematicEncoding = false;
     switch (value.dataEncoding()) {
     case TagTextEncoding::Latin1:
-    case TagTextEncoding::Unspecified:
         break;
     case TagTextEncoding::Utf8:
-        // write
+        // write UTF-8 BOM if the value contains non-ASCII characters
         for (const auto c : valueAsString) {
             if ((c & 0x80) == 0) {
                 continue;
@@ -328,10 +328,14 @@ void Id3v1Tag::writeValue(const TagValue &value, size_t length, char *buffer, os
             buffer[2] = static_cast<char>(0xBF);
             valueStart += 3;
             valueLength -= 3;
+            hasProblematicEncoding = true;
             break;
         }
-        [[fallthrough]];
+        break;
     default:
+        hasProblematicEncoding = true;
+    }
+    if (hasProblematicEncoding) {
         diag.emplace_back(DiagLevel::Warning, "The used encoding is unlikely to be supported by other software.", "making ID3v1 tag field");
     }