fix(search): close stdin on search subprocesses to prevent hang in agent contexts

[shareefhadid]

Summary

rtk rg and rtk grep search subprocesses inherit stdin from the parent
process. When RTK is invoked by an AI coding agent (Cursor, Claude Code, etc.),
the parent stdin is typically a long-lived IPC socket or pipe that never sends
EOF. Because rg enters "read from stdin" mode when it receives no terminal
stdin and the search module uses Stdio::inherit(), the subprocess blocks
indefinitely on read().

This is the same class of bug fixed in #897 / PR #979 for grep_cmd.rs, but
that fix was never applied to the search.rs path used by rtk rg.

Fix

Change exec_capture_stdin in src/core/stream.rs from Stdio::inherit() to
Stdio::null(). Search commands should never read from stdin — they always
receive explicit file/directory paths via their argument list.

Test plan

• Confirmed hang with current release: rg subprocess blocks in
  StdinLock::read when stdin is an open pipe
• Confirmed fix: search completes immediately with Stdio::null()
• Normal file search still returns correct results
• Non-search fallback commands still inherit stdin
• All existing search (76) and stream (51) tests pass

Related

• grep subprocesses leak memory catastrophically, causing macOS kernel panic #897 — original report of grep subprocess stdin leak
• PR fix(grep): close subprocess stdin to prevent memory leak (#897) #979 — Stdio::null() fix for grep_cmd.rs (merged, shipped in v0.35.0)
• rtk hook claude rewrites rg → rtk grep (BSD grep) instead of rtk rg, so path-less ripgrep searches silently return 0 matches / hang on stdin #2301 — rtk hook claude rewrites causing hangs on path-less searches

Made with Cursor

[CLAassistant]

All committers have signed the CLA.