Make <br> inline not block

Fixes #2439

Related to #2387

Author: jhy

CHANGES.md

@@ -28,6 +28,7 @@
 * When using StructuralEvaluators (e.g., a `parent child` selector) across many retained threads, their memoized results could also be retained, increasing memory use. These results are now cleared immediately after use, reducing overall memory consumption. [#2411](https://github.com/jhy/jsoup/issues/2411)
 * Cloning a `Parser` now preserves any custom `TagSet` applied to the parser. [#2422](https://github.com/jhy/jsoup/issues/2422), [#2423](https://github.com/jhy/jsoup/pull/2423)
 * Custom tags marked as `Tag.Void` now parse and serialize like the built-in void elements: they no longer consume following content, and the XML serializer emits the expected self-closing form. [#2425](https://github.com/jhy/jsoup/issues/2425)
+* The `<br>` element is once again classified as an inline tag (`Tag.isBlock() == false`), matching common developer expectations and its role as phrasing content in HTML, while pretty-printing and text extraction continue to treat it as a line break in the rendered output. [#2387](https://github.com/jhy/jsoup/issues/2387), [#2439](https://github.com/jhy/jsoup/issues/2439)
 
 ### Internal Changes
 * Deprecated internal helper `org.jsoup.internal.Functions` (for removal in v1.23.1). This was previously used to support older Android API levels without full `java.util.function` coverage; jsoup now requires core library desugaring so this indirection is no longer necessary. [#2412](https://github.com/jhy/jsoup/pull/2412)

src/main/java/org/jsoup/nodes/Printer.java

@@ -159,6 +159,7 @@ boolean isBlockEl(@Nullable Node node) {
             if (node == null) return false;
             if (node instanceof Element) {
                 Element el = (Element) node;
+                if (el.nameIs("br")) return true; // give <br> a newline; actually an inline tag
                 return el.isBlock() ||
                     (!el.tag.isKnownTag() && (el.parentNode instanceof Document || hasChildBlocks(el)));
             }

src/main/java/org/jsoup/parser/TagSet.java

@@ -212,7 +212,7 @@ static TagSet initHtmlDefault() {
         String[] blockTags = {
             "html", "head", "body", "frameset", "script", "noscript", "style", "meta", "link", "title", "frame",
             "noframes", "section", "nav", "aside", "hgroup", "header", "footer", "p", "h1", "h2", "h3", "h4", "h5",
-            "h6", "br", "button",
+            "h6", "button",
             "ul", "ol", "pre", "div", "blockquote", "hr", "address", "figure", "figcaption", "form", "fieldset", "ins",
             "del", "dl", "dt", "dd", "li", "table", "caption", "thead", "tfoot", "tbody", "colgroup", "col", "tr", "th",
             "td", "video", "audio", "canvas", "details", "menu", "plaintext", "template", "article", "main",

src/test/java/org/jsoup/parser/TagTest.java

@@ -81,6 +81,12 @@ public void canBeInsensitive(Locale locale) {
         assertFalse(p.isInline());
     }
 
+    @Test public void brSemantics() {
+        Tag br = Tag.valueOf("br");
+        assertTrue(br.isInline());
+        assertFalse(br.isBlock());
+    }
+
     @Test public void imgSemantics() {
         Tag img = Tag.valueOf("img");
         assertTrue(img.isInline());