mv: prompts to overwrite read-only file when stdin is not a terminal #11321

$ touch target && chmod 555 target
$ echo content > source
$ mv source target < /dev/null
$ # No promprt, file is moved
$ cat target

$ touch target && chmod 555 target
$ echo content > source
$ mv source target < /dev/null
mv: replace 'target', overriding mode 0555 (r-xr-xr-x)?
$ # Prompts and waits/fails, file is NOT moved

#!/usr/bin/env bash
set -e

WORKDIR=$(mktemp -d)
cd "$WORKDIR"
trap "rm -rf $WORKDIR" EXIT

# Create a read-only target file
echo "original" > target
chmod 555 target

# Create source file
echo "replacement" > source

echo "=== Testing mv with stdin redirected from /dev/null ==="
echo "Running: mv source target < /dev/null"

# This should NOT prompt when stdin is not a terminal
if timeout 2 mv source target < /dev/null 2>&1; then
    echo "PASS: mv completed without prompting"
    echo "target contents: $(cat target)"
else
    echo "FAIL: mv prompted or timed out (exit code: $?)"
    echo "GNU mv would silently overwrite the file"
fi