Bug: `pattern_search` silently drops all matches from CRLF files on Windows

[intfoo]

Description

On Windows, pattern_search (and any tool that calls runRg with line-by-line parsing) silently drops every match from files that use CRLF line endings (\r\n).

The root cause is in execPatternSearch (server.ts:1293):

const m = line.match(/^(.+?):(\d+):(.*)$/);

When ripgrep outputs matches from a CRLF file, it preserves the \r\n endings. After stdout.split("\n"), the \n is consumed but \r remains at the end of each line. Since . does not match \r and $ does not anchor before \r, the entire regex fails to match, and the line is silently skipped.

Minimal reproduction:

// CRLF line → match fails
"abc:1:hello\r".match(/^(.+?):(\d+):(.*)$/);  // null

// LF line → match succeeds
"abc:1:hello".match(/^(.+?):(\d+):(.*)$/);     // ["abc:1:hello", "abc", "1", "hello"]

Impact: Any file committed with CRLF endings (common on Windows, especially files edited in certain IDEs) is completely invisible to pattern_search. The bug is silent — no error, no warning, just missing results.

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Affected Code

src/mcp/server.ts line 1293 and any other runRg consumer that parses output line-by-line with the same regex pattern.

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Proposed Fix

Option A — Make the regex CRLF-tolerant:

- const m = line.match(/^(.+?):(\d+):(.*)$/);
+ const m = line.match(/^(.+?):(\d+):(.*)\r?$/);

Option B — Strip \r before parsing:

  for (const line of stdout.split("\n")) {
+   const clean = line.replace(/\r$/, "");
-   const m = line.match(/^(.+?):(\d+):(.*)$/);
+   const m = clean.match(/^(.+?):(\d+):(.*)$/);

Option B is more defensive and benefits any future regex changes that might forget \r?.

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Reproduction Steps

1. Create a CRLF test file on Windows:

   mkdir -p /tmp/test-project
   printf "export class Hello {\r\n  world() {}\r\n}\r\n" > /tmp/test-project/hello.js

2. Create an LF test file in the same directory:

   printf "export class Hello {\n  world() {}\n}\n" > /tmp/test-project/hello-lf.js

3. Run lexis MCP against this project and call pattern_search:

   {
     "tool": "pattern_search",
     "arguments": { "pattern": "Hello" }
   }

4. Expected: Both hello.js and hello-lf.js appear in results.

5. Actual: Only hello-lf.js appears. hello.js is silently missing.

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Environment

• OS: Windows 10/11 (CRLF is the default line ending)
• Node.js: v22.x
• ripgrep: 15.0.0 (bundled via @vscode/ripgrep)
• lexis-mcp: latest

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Additional Notes

• The same regex pattern may also affect other runRg consumers in server.ts. A grep for (.+?):(\d+):(.*) would reveal all occurrences that need patching.
• search_code also calls runRg internally and likely has the same issue if it parses stdout line-by-line.
• This bug is particularly insidious because it is silent — no error, no warning, just missing results. On a mixed-line-ending project (common in teams with both Windows and macOS/Linux devs), some files will appear in search results and others won't, with no obvious pattern to the user.