m3u: check NL after signature for fewer false-positives

Author: gabriel-vasile

internal/magic/audio.go

@@ -40,9 +40,10 @@ func Voc(raw []byte, _ uint32) bool {
 	return bytes.HasPrefix(raw, []byte("Creative Voice File"))
 }
 
-// M3u matches a Playlist file.
-func M3u(raw []byte, _ uint32) bool {
-	return bytes.HasPrefix(raw, []byte("#EXTM3U"))
+// M3U matches a Playlist file.
+func M3U(raw []byte, _ uint32) bool {
+	return bytes.HasPrefix(raw, []byte("#EXTM3U\n")) ||
+		bytes.HasPrefix(raw, []byte("#EXTM3U\r\n"))
 }
 
 // AAC matches an Advanced Audio Coding file.

mimetype_test.go

@@ -196,7 +196,7 @@ a,"b`,
 	{"lua", "#!/usr/bin/lua", "text/x-lua", one},
 	{"lua space", "#! /usr/bin/lua", "text/x-lua", none},
 	{"lz", "\x4c\x5a\x49\x50", "application/lzip", one},
-	{"m3u", "#EXTM3U", "application/vnd.apple.mpegurl", one},
+	{"m3u", "#EXTM3U\n", "application/vnd.apple.mpegurl", one},
 	{"m4a", "\x00\x00\x00\x18ftypM4A ", "audio/x-m4a", one},
 	{"audio mp4 F4A", "\x00\x00\x00\x18ftypF4A ", "audio/mp4", one},
 	{"audio mp4 F4B", "\x00\x00\x00\x18ftypF4B ", "audio/mp4", none},

tree.go

@@ -174,7 +174,7 @@ var (
 	aMp4 = newMIME("audio/mp4", ".mp4", magic.AMp4).
 		alias("audio/x-mp4a")
 	m4a = newMIME("audio/x-m4a", ".m4a", magic.M4a)
-	m3u = newMIME("application/vnd.apple.mpegurl", ".m3u", magic.M3u).
+	m3u = newMIME("application/vnd.apple.mpegurl", ".m3u", magic.M3U).
 		alias("audio/mpegurl", "application/x-mpegurl")
 	m4v  = newMIME("video/x-m4v", ".m4v", magic.M4v)
 	mj2  = newMIME("video/mj2", ".mj2", magic.Mj2)