From fcf6f084756627cb49ad65999fe3718fd5d19078 Mon Sep 17 00:00:00 2001
From: Cyril Hrubis <metan@ucw.cz>
Date: Mon, 27 Jul 2026 05:08:18 +0200
Subject: [PATCH] treebuilder: treat <source> and <track> as void elements
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

libhubbub predates the HTML5 <source>/<track> elements, so they were
absent from the gperf element-type wordlist.  element_type_from_name
returned UNKNOWN for them and the "any other start tag" path pushed
<source> onto the open-elements stack as a non-void container — the
following <img> then nested inside the <source> instead of becoming its
sibling under <picture>.  In the standard `<source>…<img>` order (sources
first, fallback img last) a downstream consumer that ignores <source>
never sees the <img>, dropping the picture entirely.

Add both to the wordlist so the generated perfect hash knows them (which
also makes element_type_to_name answer for them), and add them to the
void-element branch so they insert without being pushed.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: Cyril Hrubis <metan@ucw.cz>
---
 src/treebuilder/element-type.gperf | 2 ++
 src/treebuilder/element-type.h     | 4 ++--
 src/treebuilder/in_body.c          | 7 ++++---
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/src/treebuilder/element-type.gperf b/src/treebuilder/element-type.gperf
index c0980d3..10b93da 100644
--- a/src/treebuilder/element-type.gperf
+++ b/src/treebuilder/element-type.gperf
@@ -110,6 +110,7 @@ s,                   S
 script,              SCRIPT
 select,              SELECT
 small,               SMALL
+source,              SOURCE
 spacer,              SPACER
 strike,              STRIKE
 strong,              STRONG
@@ -125,6 +126,7 @@ th,                  TH
 thead,               THEAD
 title,               TITLE
 tr,                  TR
+track,               TRACK
 tt,                  TT
 u,                   U
 ul,                  UL
diff --git a/src/treebuilder/element-type.h b/src/treebuilder/element-type.h
index 75612fd..02a396e 100644
--- a/src/treebuilder/element-type.h
+++ b/src/treebuilder/element-type.h
@@ -20,8 +20,8 @@ typedef enum
 	FORM, FRAME, FRAMESET, H1, H2, H3, H4, H5, H6, HEAD, HEADER, HR, IFRAME,
 	IMAGE, IMG, INPUT, ISINDEX, LI, LINK, LISTING, MAIN, MENU, META, NAV,
 	NOEMBED, NOFRAMES, NOSCRIPT, OL, OPTGROUP, OPTION, P, PARAM, PLAINTEXT,
-	PRE, SCRIPT, SECTION, SELECT, SPACER, STYLE, SUMMARY, TBODY, TEXTAREA,
-	TFOOT, THEAD, TITLE, TR, UL, WBR,
+	PRE, SCRIPT, SECTION, SELECT, SOURCE, SPACER, STYLE, SUMMARY, TBODY,
+	TEXTAREA, TFOOT, THEAD, TITLE, TR, TRACK, UL, WBR,
 /* Scoping */
 	APPLET, BUTTON, CAPTION, HTML, MARQUEE, OBJECT, TABLE, TD, TH,
 /* Formatting */
diff --git a/src/treebuilder/in_body.c b/src/treebuilder/in_body.c
index 0e4184c..765ea38 100644
--- a/src/treebuilder/in_body.c
+++ b/src/treebuilder/in_body.c
@@ -322,10 +322,11 @@ hubbub_error process_start_tag(hubbub_treebuilder *treebuilder,
 				current_table(treebuilder)].tainted = false;
 			treebuilder->context.mode = IN_TABLE;
 		}
-	} else if (type == AREA || type == BASEFONT || 
-			type == BGSOUND || type == BR || 
+	} else if (type == AREA || type == BASEFONT ||
+			type == BGSOUND || type == BR ||
 			type == EMBED || type == IMG || type == INPUT ||
-			type == PARAM || type == SPACER || type == WBR) {
+			type == PARAM || type == SOURCE || type == SPACER ||
+			type == TRACK || type == WBR) {
 		err = reconstruct_active_formatting_list(treebuilder);
 		if (err != HUBBUB_OK)
 			return err;