From 2e1f07bac27fbcd81dcaa56032d6f2209b8745b8 Mon Sep 17 00:00:00 2001
From: Mario Zechner <badlogicgames@gmail.com>
Date: Sat, 23 May 2026 09:53:36 +0200
Subject: [PATCH] fix(coding-agent): avoid invalid footer home abbreviation

closes #4878
---
 packages/coding-agent/CHANGELOG.md            |  1 +
 .../modes/interactive/components/footer.ts    | 21 ++++++++++++++-----
 .../coding-agent/test/footer-width.test.ts    | 13 +++++++++++-
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 83253924..ba96b2a8 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -22,6 +22,7 @@
 - Published a 0.74.2 rescue release that tells Node 20 users to upgrade Node before updating to newer Pi versions ([#4876](https://github.com/earendil-works/pi/issues/4876)).
 - Fixed final bash tool cards to avoid rendering duplicate full-output truncation paths ([#4819](https://github.com/earendil-works/pi/issues/4819)).
 - Fixed bash tool truncation line counts to ignore the trailing newline as an extra output line ([#4818](https://github.com/earendil-works/pi/issues/4818)).
+- Fixed footer home-directory abbreviation to avoid shortening sibling paths that only share the same prefix ([#4878](https://github.com/earendil-works/pi/issues/4878)).
 
 ## [0.75.4] - 2026-05-20
 
diff --git a/packages/coding-agent/src/modes/interactive/components/footer.ts b/packages/coding-agent/src/modes/interactive/components/footer.ts
index a48898a5..47ff58ae 100644
--- a/packages/coding-agent/src/modes/interactive/components/footer.ts
+++ b/packages/coding-agent/src/modes/interactive/components/footer.ts
@@ -1,3 +1,4 @@
+import { isAbsolute, relative, resolve, sep } from "node:path";
 import { type Component, truncateToWidth, visibleWidth } from "@earendil-works/pi-tui";
 import type { AgentSession } from "../../../core/agent-session.ts";
 import type { ReadonlyFooterDataProvider } from "../../../core/footer-data-provider.ts";
@@ -26,6 +27,20 @@ function formatTokens(count: number): string {
 	return `${Math.round(count / 1000000)}M`;
 }
 
+export function formatCwdForFooter(cwd: string, home: string | undefined): string {
+	if (!home) return cwd;
+
+	const resolvedCwd = resolve(cwd);
+	const resolvedHome = resolve(home);
+	const relativeToHome = relative(resolvedHome, resolvedCwd);
+	const isInsideHome =
+		relativeToHome === "" ||
+		(relativeToHome !== ".." && !relativeToHome.startsWith(`..${sep}`) && !isAbsolute(relativeToHome));
+
+	if (!isInsideHome) return cwd;
+	return relativeToHome === "" ? "~" : `~${sep}${relativeToHome}`;
+}
+
 /**
  * Footer component that shows pwd, token stats, and context usage.
  * Computes token/context stats from session, gets git branch and extension statuses from provider.
@@ -92,11 +107,7 @@ export class FooterComponent implements Component {
 		const contextPercent = contextUsage?.percent !== null ? contextPercentValue.toFixed(1) : "?";
 
 		// Replace home directory with ~
-		let pwd = this.session.sessionManager.getCwd();
-		const home = process.env.HOME || process.env.USERPROFILE;
-		if (home && pwd.startsWith(home)) {
-			pwd = `~${pwd.slice(home.length)}`;
-		}
+		let pwd = formatCwdForFooter(this.session.sessionManager.getCwd(), process.env.HOME || process.env.USERPROFILE);
 
 		// Add git branch if available
 		const branch = this.footerData.getGitBranch();
diff --git a/packages/coding-agent/test/footer-width.test.ts b/packages/coding-agent/test/footer-width.test.ts
index 2d912647..d5586d7d 100644
--- a/packages/coding-agent/test/footer-width.test.ts
+++ b/packages/coding-agent/test/footer-width.test.ts
@@ -2,7 +2,7 @@ import { visibleWidth } from "@earendil-works/pi-tui";
 import { beforeAll, describe, expect, it } from "vitest";
 import type { AgentSession } from "../src/core/agent-session.ts";
 import type { ReadonlyFooterDataProvider } from "../src/core/footer-data-provider.ts";
-import { FooterComponent } from "../src/modes/interactive/components/footer.ts";
+import { FooterComponent, formatCwdForFooter } from "../src/modes/interactive/components/footer.ts";
 import { initTheme } from "../src/modes/interactive/theme/theme.ts";
 
 type AssistantUsage = {
@@ -73,6 +73,17 @@ function createFooterData(providerCount: number): ReadonlyFooterDataProvider {
 	return provider;
 }
 
+describe("formatCwdForFooter", () => {
+	it("does not abbreviate sibling paths that share the home prefix", () => {
+		expect(formatCwdForFooter("/home/user2", "/home/user")).toBe("/home/user2");
+	});
+
+	it("abbreviates the home directory and descendants", () => {
+		expect(formatCwdForFooter("/home/user", "/home/user")).toBe("~");
+		expect(formatCwdForFooter("/home/user/project", "/home/user")).toBe("~/project");
+	});
+});
+
 describe("FooterComponent width handling", () => {
 	beforeAll(() => {
 		initTheme(undefined, false);