From b16f668795daa16eff915c416feefc74e5b3e4c4 Mon Sep 17 00:00:00 2001
From: Evan Jacobs <570070+quantizor@users.noreply.github.com>
Date: Tue, 12 Nov 2024 00:13:21 -0500
Subject: [PATCH] fix: false detection of nested list due to bad lookback cache
 (#614)

* fix: false detection of nested list due to bad lookback cache

* chore: add changeset
---
 .changeset/eighty-bees-think.md |  5 +++++
 index.compiler.spec.tsx         | 31 +++++++++++++++++++++++++++++--
 index.tsx                       | 22 ++++++++++++++++------
 3 files changed, 50 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/eighty-bees-think.md

diff --git a/.changeset/eighty-bees-think.md b/.changeset/eighty-bees-think.md
new file mode 100644
index 00000000..73e27786
--- /dev/null
+++ b/.changeset/eighty-bees-think.md
@@ -0,0 +1,5 @@
+---
+'markdown-to-jsx': patch
+---
+
+Fix issue with lookback cache resulting in false detection of lists inside lists in some scenarios
diff --git a/index.compiler.spec.tsx b/index.compiler.spec.tsx
index 08d3d39f..26388e6a 100644
--- a/index.compiler.spec.tsx
+++ b/index.compiler.spec.tsx
@@ -1760,6 +1760,33 @@ describe('lists', () => {
       </div>
     `)
   })
+
+  it('regression #613 - list false detection inside inline syntax', () => {
+    render(
+      compiler(`
+- foo
+- bar **+ baz** qux **quux**
+      `)
+    )
+
+    expect(root.innerHTML).toMatchInlineSnapshot(`
+      <ul>
+        <li>
+          foo
+        </li>
+        <li>
+          bar
+          <strong>
+            + baz
+          </strong>
+          qux
+          <strong>
+            quux
+          </strong>
+        </li>
+      </ul>
+    `)
+  })
 })
 
 describe('GFM task lists', () => {
@@ -4314,12 +4341,12 @@ describe('options.renderRule', () => {
   it('should allow arbitrary modification of content', () => {
     render(
       compiler('Hello.\n\n```latex\n$$f(X,n) = X_n + X_{n-1}$$\n```\n', {
-        renderRule(defaultRenderer, node, renderChildren, state) {
+        renderRule(next, node, renderChildren, state) {
           if (node.type === RuleType.codeBlock && node.lang === 'latex') {
             return <div key={state.key}>I'm latex.</div>
           }
 
-          return defaultRenderer()
+          return next()
         },
       })
     )
diff --git a/index.tsx b/index.tsx
index ad34347e..e94e8762 100644
--- a/index.tsx
+++ b/index.tsx
@@ -424,7 +424,7 @@ function generateListRule(
     : UNORDERED_LIST_ITEM_PREFIX_R
 
   return {
-    match(source, state, prevCapture) {
+    match(source, state) {
       // We only want to break into a list if we are at the start of a
       // line. This is to avoid parsing "hi * there" with "* there"
       // becoming a part of a list.
@@ -433,7 +433,7 @@ function generateListRule(
       // lists can be inline, because they might be inside another list,
       // in which case we can parse with inline scope, but need to allow
       // nested lists inside this inline scope.
-      const isStartOfLine = LIST_LOOKBEHIND_R.exec(prevCapture)
+      const isStartOfLine = LIST_LOOKBEHIND_R.exec(state.prevCapture)
       const isListBlock = state.list || (!state.inline && !state.simple)
 
       if (isStartOfLine && isListBlock) {
@@ -837,21 +837,28 @@ function parserFor(
   ): MarkdownToJSX.ParserResult[] {
     let result = []
 
+    state.prevCapture = state.prevCapture || ''
+
     // We store the previous capture so that match functions can
     // use some limited amount of lookbehind. Lists use this to
     // ensure they don't match arbitrary '- ' or '* ' in inline
     // text (see the list rule for more information).
-    let prevCapture = ''
     while (source) {
       let i = 0
       while (i < ruleList.length) {
         const ruleType = ruleList[i]
         const rule = rules[ruleType]
-        const capture = rule.match(source, state, prevCapture)
+
+        const capture = rule.match(source, state)
 
         if (capture) {
           const currCaptureString = capture[0]
+
+          // retain what's been processed so far for lookbacks
+          state.prevCapture += currCaptureString
+
           source = source.substring(currCaptureString.length)
+
           const parsed = rule.parse(capture, nestedParse, state)
 
           // We also let rules override the default type of
@@ -863,8 +870,6 @@ function parserFor(
           }
 
           result.push(parsed)
-
-          prevCapture = currCaptureString
           break
         }
 
@@ -872,6 +877,9 @@ function parserFor(
       }
     }
 
+    // reset on exit
+    state.prevCapture = ''
+
     return result
   }
 
@@ -2018,6 +2026,8 @@ export namespace MarkdownToJSX {
     key?: React.Key
     /** true if in a list */
     list?: boolean
+    /** used for lookbacks */
+    prevCapture?: string
     /** true if parsing in inline context w/o links */
     simple?: boolean
   }