From 83b05755db5abec627bfc98c6fbc0ac0253fd84c Mon Sep 17 00:00:00 2001
From: Alex Kocharin <alex@kocharin.ru>
Date: Mon, 23 Nov 2020 17:44:18 +0300
Subject: [PATCH] Fix quadratic time on emphasis

close https://github.com/markdown-it/markdown-it/issues/735
---
 CHANGELOG.md                      | 1 +
 lib/rules_inline/balance_pairs.js | 4 +---
 test/pathological.js              | 6 ++++++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index decb77cb0..b45a881e7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `[](url (xxx())` is no longer a valid link.
 - Fix performance issues when parsing links, #732, #734.
 - Fix performance issues when parsing backticks, #733.
+- Fix performance issues when parsing emphases, #735.
 
 
 ## [12.0.2] - 2020-10-23
diff --git a/lib/rules_inline/balance_pairs.js b/lib/rules_inline/balance_pairs.js
index 8d649bf43..4278c8ec8 100644
--- a/lib/rules_inline/balance_pairs.js
+++ b/lib/rules_inline/balance_pairs.js
@@ -27,17 +27,15 @@ function processDelimiters(state, delimiters) {
     }
 
     minOpenerIdx = openersBottom[closer.marker][closer.length % 3];
-    newMinOpenerIdx = -1;
 
     openerIdx = closerIdx - closer.jump - 1;
+    newMinOpenerIdx = openerIdx;
 
     for (; openerIdx > minOpenerIdx; openerIdx -= opener.jump + 1) {
       opener = delimiters[openerIdx];
 
       if (opener.marker !== closer.marker) continue;
 
-      if (newMinOpenerIdx === -1) newMinOpenerIdx = openerIdx;
-
       if (opener.open && opener.end < 0) {
 
         isOddMatch = false;
diff --git a/test/pathological.js b/test/pathological.js
index fb7e44a64..a905dc551 100644
--- a/test/pathological.js
+++ b/test/pathological.js
@@ -117,4 +117,10 @@ describe('Pathological sequences speed', () => {
       await test_pattern('[a](b'.repeat(30000));
     });
   });
+
+  describe('Markdown-it', () => {
+    it('emphasis **_* pattern', async () => {
+      await test_pattern('**_* '.repeat(50000));
+    });
+  });
 });