Fix breaks (#1507)

Fix breaks

Author: UziTech

lib/marked.js

@@ -634,7 +634,10 @@ inline.gfm.url = edit(inline.gfm.url, 'i')
 
 inline.breaks = merge({}, inline.gfm, {
   br: edit(inline.br).replace('{2,}', '*').getRegex(),
-  text: edit(inline.gfm.text).replace(/\{2,\}/g, '*').getRegex()
+  text: edit(inline.gfm.text)
+    .replace('\\b_', '\\b_| {2,}\\n')
+    .replace(/\{2,\}/g, '*')
+    .getRegex()
 });
 
 /**

test/specs/new/breaks.html

@@ -0,0 +1 @@
+<p>A<br>B</p>

test/specs/new/breaks.md

@@ -0,0 +1,6 @@
+---
+breaks: true
+gfm: true
+---
+A
+B