use global replace

Author: UziTech

src/Tokenizer.ts

@@ -157,7 +157,7 @@ export class _Tokenizer {
     const cap = this.rules.block.blockquote.exec(src);
     if (cap) {
       // preceded setext continuation with 4 spaces so it isn't a setext
-      let text = cap[0].replace(/\n {0,3}((?:=+|-+) *(?:\n|$))/, '\n    $1');
+      let text = cap[0].replace(/\n {0,3}((?:=+|-+) *)(?=\n|$)/g, '\n    $1');
       text = rtrim(text.replace(/^ *>[ \t]?/gm, ''), '\n');
       const top = this.lexer.state.top;
       this.lexer.state.top = true;

test/specs/new/blockquote_setext.html

@@ -9,6 +9,11 @@
 <blockquote>
   <h1>heading 1</h1>
 </blockquote>
+
 <blockquote>
   <h2>heading 2</h2>
 </blockquote>
+
+<blockquote>
+  <p>not heading 1 == not heading 2 with br<br />--</p>
+</blockquote>

test/specs/new/blockquote_setext.md

@@ -9,3 +9,8 @@
 
 > heading 2
 > --
+
+> not heading 1
+==
+> not heading 2 with br  
+--