---
id: "bug-1716"
status: "fixed"
status_updated: "2026-09-24"
status_note: ""
component: "controller"
severity: "unknown"
timestamp: "2026-08-26T14:25:00Z"
last_seen: "2026-09-19T09:00:00Z"
occurrences: 1
files: ["src/controller/testsuite/rcfile.c"]
tags: ["rcfile", "fopen", "EISDIR", "directory", "getline", "xce-test-rc-file", "controller-testsuite", "stderr-warning"]
related: []
legacy: true
---

# bug-1716: test_rcfile_load_directory_path_warns_and_returns_0:FAIL: Expected TRUE Was FALSE (stderr capture…

## Description
test_rcfile_load_directory_path_warns_and_returns_0:FAIL: Expected TRUE Was FALSE (stderr capture was empty -- no warning printed) when rcfile_load() opened a directory path

## Environment
_Not recorded (migrated from buglog.json)._

## Reproduction
_Not recorded (migrated from buglog.json)._

## Root cause
On this platform (glibc/Linux), fopen(path, "r") SUCCEEDS for a directory path -- it does not return NULL/set errno the way the design doc's error-handling section (and a naive reading of 'the file could not be opened for another reason') implied. The open failure only surfaces on the FIRST READ: getline() returns -1 with errno==EISDIR and ferror(f) set (feof(f) stays 0). rcfile_load()'s original implementation only checked `if (!f)` right after fopen() and had no post-loop check on the stream's error state, so a directory path silently produced rc=0 with zero lines processed and NO warning ever printed -- functionally 'safe' (no crash, no runner call) but silently violating the design's documented 'present but unreadable: print one stderr warning' contract for exactly this case.

## Fix
Added a check after the getline() loop in rcfile_load(): `if (rc == 0 && ferror(f)) { fprintf(stderr, ...); }` -- prints the same warning message used for the fopen()-failure branch, keyed off ferror(f) rather than assuming the failure is only detectable at fopen() time. Confirmed live via a small standalone C repro (fopen("/tmp","r") then fread/getline) that fopen() returns a valid FILE* for a directory and the read call is what fails with EISDIR + ferror set.

## Verification
_Not recorded (migrated from buglog.json)._

## References
_Not recorded (migrated from buglog.json)._