commit e5a2561859aaf24e6368af6a4e82fc8112bc3d08
from: Oliver Lowe <o@olowe.co>
date: Sun May  4 04:02:40 2025 UTC

m3u8: ignore trailing commas, support quoted string attributes

Playlist from
https://test-streams.mux.dev/dai-discontinuity-deltatre/manifest.m3u8
containing discontinuities exposed the bugs.

commit - 3083e3dd1cb493efa7557138726614b1d3758e81
commit + e5a2561859aaf24e6368af6a4e82fc8112bc3d08
blob - e3d28a0f2d8b84a79679df36ff2b10219b4b703d
blob + 72a79eb6300b633779d9890cb85f70b5f0cb7bc8
--- m3u8/lex.go
+++ m3u8/lex.go
@@ -127,6 +127,7 @@ func newLexer(r io.Reader) *lexer {
 	return &lexer{
 		sc:    bufio.NewScanner(r),
 		items: make(chan item),
+		debug: false,
 	}
 }
 
@@ -135,7 +136,10 @@ func lexStart(l *lexer) stateFn {
 		if l.sc.Text() == "" {
 			continue // ignore blank lines
 		}
-		l.input = l.sc.Text() + "\n"
+		text := l.sc.Text()
+		// ignore valid but meaningless trailing commas.
+		text = strings.TrimSuffix(text, ",")
+		l.input = text + "\n"
 		l.pos = 0
 		l.start = 0
 		if strings.HasPrefix(l.input, tagStart) {
@@ -145,7 +149,7 @@ func lexStart(l *lexer) stateFn {
 		}
 		// not a tag, so must be a URL.
 		// emit the URL, then the newline we appended ourselves.
-		l.pos = len(l.sc.Text())
+		l.pos = len(text)
 		l.emit(itemURL)
 		l.emit(itemNewline)
 	}
@@ -179,7 +183,7 @@ func lexTagName(l *lexer) stateFn {
 		case ':':
 			l.emit(itemTag)
 			l.next()
-			l.ignore()
+			l.ignore() // ignore ':' after tag name
 			return lexAttrs(l)
 		}
 		return l.errorf("illegal tag character %q", r)
@@ -225,6 +229,9 @@ func lexAttrs(l *lexer) stateFn {
 			return lexAttrValue(l)
 		case r == '@':
 			return lexAttrValue(l)
+		case r == '"':
+			l.next()
+			return lexQString(l)
 		default:
 			return l.errorf("illegal character %q in attribute name", r)
 		}
blob - /dev/null
blob + 79e1a52b3948e69c1df6200c4fcc9cb9165588a3 (mode 644)
--- /dev/null
+++ m3u8/testdata/discontinuities.m3u8
@@ -0,0 +1,78 @@
+#EXTM3U
+#EXT-X-YOSPACE-ANALYTICS-URL:"https://csm-e-cebteurxaws416-2hjvnjz85og7.tls1.yospace.com/csm/analytics;jsessionid=E97CB20FD3BCE93F89ADDB12E8C82895.csm-e-cebteurxaws416-2hjvnjz85og7.tls1.yospace.com"
+#EXT-X-TARGETDURATION:10
+#EXT-X-VERSION:3
+#EXT-X-PLAYLIST-TYPE:EVENT
+#EXT-X-KEY:METHOD=AES-128,URI="key1.json?f=1041&s=0&p=1822767&m=1506045858",IV=0x000000000000000000000000001BD02F
+#EXTINF:10,
+1041_6_1822767.ts?m=1506045858
+#EXT-X-KEY:METHOD=AES-128,URI="key2.json?f=1041&s=0&p=1822768&m=1506045858",IV=0x000000000000000000000000001BD030
+#EXTINF:10,
+1041_6_1822768.ts?m=1506045858
+#EXT-X-KEY:METHOD=AES-128,URI="key3.json?f=1041&s=0&p=1822769&m=1506045858",IV=0x000000000000000000000000001BD031
+#EXTINF:10,
+1041_6_1822769.ts?m=1506045858
+#EXT-X-KEY:METHOD=AES-128,URI="key4.json?f=1041&s=0&p=1822770&m=1506045858",IV=0x000000000000000000000000001BD032
+#EXTINF:6.28,
+1041_6_1822770.ts?m=1506045858
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=NONE
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-1.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-2.ts
+#EXTINF:7.2,
+u-6400-m-720x408-1628-a-96-1-3.ts
+#EXTINF:2.8,
+u-6400-m-720x408-1628-a-96-1-4.ts
+#EXT-X-DISCONTINUITY
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-1-1.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-2-1.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-3-1.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-4-1.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-5.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-6.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-7.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-8.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-9.ts
+#EXTINF:7.56,
+u-6400-m-720x408-1628-a-96-1-10.ts
+#EXTINF:2.44,
+u-6400-m-720x408-1628-a-96-1-11.ts
+#EXT-X-DISCONTINUITY
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-1-2.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-2.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-3-2.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-4-2.ts
+#EXTINF:10,
+u-6400-m-720x408-1628-a-96-1-5-1.ts
+#EXT-X-DISCONTINUITY
+#EXT-X-KEY:METHOD=AES-128,URI="key5.json?f=1041&s=0&p=1822791&m=1506045858",IV=0x000000000000000000000000001BD047
+#EXTINF:9.72,
+1041_6_1822791.ts?m=1506045858
+#EXT-X-KEY:METHOD=AES-128,URI="key6.json?f=1041&s=0&p=1822792&m=1506045858",IV=0x000000000000000000000000001BD048
+#EXTINF:10,
+1041_6_1822792.ts?m=1506045858
+#EXT-X-KEY:METHOD=AES-128,URI="key7.json?f=1041&s=0&p=1822793&m=1506045858",IV=0x000000000000000000000000001BD049
+#EXTINF:10,
+1041_6_1822793.ts?m=1506045858
+#EXT-X-KEY:METHOD=AES-128,URI="key8.json?f=1041&s=0&p=1822794&m=1506045858",IV=0x000000000000000000000000001BD04A
+#EXTINF:10,
+1041_6_1822794.ts?m=1506045858
+#EXT-X-KEY:METHOD=AES-128,URI="key9.json?f=1041&s=0&p=1822795&m=1506045858",IV=0x000000000000000000000000001BD04B
+#EXTINF:10,
+1041_6_1822795.ts?m=1506045858
+#EXT-X-ENDLIST
\ No newline at end of file