From 8c4e873899b97f6abd14bc45928ccb465f83010c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20Hou=C5=A1ka?= <houskape@gmail.com>
Date: Wed, 21 Oct 2026 21:25:32 +0200
Subject: [PATCH] fix(coding-agent): grep tool ignores ripgrep config via
 --no-config

The built-in grep tool spawned rg with the inherited environment, so
RIPGREP_CONFIG_PATH (e.g. a config containing --fixed-strings) silently
changed tool semantics: literal: false searches became literal and the
agent got incomplete results with no error.

Pass --no-config so the tool contract is deterministic. Users who want
custom rg behavior can use the bash tool or wrap grep in an extension.

closes #11203
---
 packages/coding-agent/src/core/tools/grep.ts |  4 +++-
 packages/coding-agent/test/tools.test.ts     | 25 ++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/packages/coding-agent/src/core/tools/grep.ts b/packages/coding-agent/src/core/tools/grep.ts
index 44f7e212b..a9562c69f 100644
--- a/packages/coding-agent/src/core/tools/grep.ts
+++ b/packages/coding-agent/src/core/tools/grep.ts
@@ -159,7 +159,9 @@ export function createGrepToolDefinition(
 							return lines;
 						};
 
-						const args: string[] = ["--json", "--line-number", "--color=never", "--hidden"];
+						// --no-config: the tool contract (literal, glob, limit, ...) must not depend on
+						// ambient user config like RIPGREP_CONFIG_PATH. Users can customize via bash or extensions.
+						const args: string[] = ["--no-config", "--json", "--line-number", "--color=never", "--hidden"];
 						if (ignoreCase) args.push("--ignore-case");
 						if (literal) args.push("--fixed-strings");
 						if (glob) args.push("--glob", glob);
diff --git a/packages/coding-agent/test/tools.test.ts b/packages/coding-agent/test/tools.test.ts
index ae1644396..91432623f 100644
--- a/packages/coding-agent/test/tools.test.ts
+++ b/packages/coding-agent/test/tools.test.ts
@@ -908,6 +908,31 @@ describe("Coding Agent Tools", () => {
 			expect(output).not.toContain("match two");
 		});
 
+		// https://github.com/earendil-works/pi/issues/11203
+		it("should ignore RIPGREP_CONFIG_PATH", async () => {
+			const configFile = join(testDir, "rg-config");
+			const testFile = join(testDir, "fixture.txt");
+			writeFileSync(configFile, "--fixed-strings\n");
+			writeFileSync(testFile, "aXb\na.b\n");
+
+			const previous = process.env.RIPGREP_CONFIG_PATH;
+			process.env.RIPGREP_CONFIG_PATH = configFile;
+			try {
+				const result = await grepTool.execute("test-call-rg-config", {
+					pattern: "a.b",
+					path: testFile,
+					literal: false,
+				});
+
+				const output = getTextOutput(result);
+				expect(output).toContain("fixture.txt:1: aXb");
+				expect(output).toContain("fixture.txt:2: a.b");
+			} finally {
+				if (previous === undefined) delete process.env.RIPGREP_CONFIG_PATH;
+				else process.env.RIPGREP_CONFIG_PATH = previous;
+			}
+		});
+
 		it("should treat flag-like patterns as search text", async () => {
 			const marker = join(testDir, "grep-injection-marker");
 			const payload = join(testDir, "payload.sh");