fix: fix infinite loop for indented code blank line (#3947)

UziTech · web-flow · commit 58a52e8a49c6 · 2026-04-18T07:06:46.000-06:00
* fix: fix infinite loop for indented code blank line

* set redos tests to not silent

* simplify test

* fix test
diff --git a/src/Lexer.ts b/src/Lexer.ts
@@ -110,7 +110,15 @@ export class _Lexer<ParserOutput = string, RendererOutput = string> {
       src = src.replace(other.tabCharGlobal, '    ').replace(other.spaceLine, '');
     }
 
+    let srcLength = Infinity;
     while (src) {
+      if (src.length < srcLength) {
+        srcLength = src.length;
+      } else {
+        this.infiniteLoopError(src.charCodeAt(0));
+        break;
+      }
+
       let token: Tokens.Generic | undefined;
 
       if (this.options.extensions?.block?.some((extTokenizer) => {
@@ -275,13 +283,8 @@ export class _Lexer<ParserOutput = string, RendererOutput = string> {
       }
 
       if (src) {
-        const errMsg = 'Infinite loop on byte: ' + src.charCodeAt(0);
-        if (this.options.silent) {
-          console.error(errMsg);
-          break;
-        } else {
-          throw new Error(errMsg);
-        }
+        this.infiniteLoopError(src.charCodeAt(0));
+        break;
       }
     }
 
@@ -334,7 +337,15 @@ export class _Lexer<ParserOutput = string, RendererOutput = string> {
 
     let keepPrevChar = false;
     let prevChar = '';
+    let srcLength = Infinity;
     while (src) {
+      if (src.length < srcLength) {
+        srcLength = src.length;
+      } else {
+        this.infiniteLoopError(src.charCodeAt(0));
+        break;
+      }
+
       if (!keepPrevChar) {
         prevChar = '';
       }
@@ -464,16 +475,20 @@ export class _Lexer<ParserOutput = string, RendererOutput = string> {
       }
 
       if (src) {
-        const errMsg = 'Infinite loop on byte: ' + src.charCodeAt(0);
-        if (this.options.silent) {
-          console.error(errMsg);
-          break;
-        } else {
-          throw new Error(errMsg);
-        }
+        this.infiniteLoopError(src.charCodeAt(0));
+        break;
       }
     }
 
     return tokens;
   }
+
+  private infiniteLoopError(byte: number) {
+    const errMsg = 'Infinite loop on byte: ' + byte;
+    if (this.options.silent) {
+      console.error(errMsg);
+    } else {
+      throw new Error(errMsg);
+    }
+  }
 }
diff --git a/src/helpers.ts b/src/helpers.ts
@@ -112,7 +112,7 @@ export function rtrim(str: string, c: string, invert?: boolean) {
 export function trimTrailingBlankLines(str: string) {
   const lines = str.split('\n');
   let end = lines.length - 1;
-  while (end >= 0 && !lines[end].trim()) {
+  while (end >= 0 && other.blankLine.test(lines[end])) {
     end--;
   }
   if (lines.length - end <= 2) {
diff --git a/test/run-spec-tests.js b/test/run-spec-tests.js
@@ -47,4 +47,5 @@ runTests({
 runTests({
   tests: redosTests,
   parse,
+  defaultMarkedOptions: { silent: false },
 });
diff --git a/test/specs/redos/code_blank_line.cjs b/test/specs/redos/code_blank_line.cjs
@@ -0,0 +1,4 @@
+module.exports = {
+  markdown: '\t\v\n',
+  html: '<pre><code>\v</code></pre>\n',
+};

Original file line number	Diff line number	Diff line change
`@@ -112,7 +112,7 @@ export function rtrim(str: string, c: string, invert?: boolean) {`
`112`	`112`	`export function trimTrailingBlankLines(str: string) {`
`113`	`113`	`const lines = str.split('\n');`
`114`	`114`	`let end = lines.length - 1;`
`115`		`- while (end >= 0 && !lines[end].trim()) {`
	`115`	`+ while (end >= 0 && other.blankLine.test(lines[end])) {`
`116`	`116`	`end--;`
`117`	`117`	`}`
`118`	`118`	`if (lines.length - end <= 2) {`