#!/bin/bash
# Verify that trying to write to a directory results in failure.

if [[ $# != 2 ]]; then
   echo "$0 <split_png.exe> <input.png>"
   exit 1
fi

SPLITTER=$1
INPUT=$2
MSG=$(mktemp -p .)
WRITABLE_OUTPUT=$(mktemp -p .)
UNWRITABLE_OUTPUT=$(mktemp -d -p .)

# Disable leak checking for ASAN, since we intentionally don't free memory.
export ASAN_OPTIONS=detect_leaks=0

function die
{
   echo "$1"
   rm -f "$MSG" "$WRITABLE_OUTPUT"
   rmdir "$UNWRITABLE_OUTPUT"
   exit 1
}

# Check exit status.
if ( "./$SPLITTER" "$INPUT" "$UNWRITABLE_OUTPUT" "$WRITABLE_OUTPUT" > "$MSG" ); then
   die "$LINENO: Unexpected success."
fi

# Check error message.
if ! ( grep -qF "$UNWRITABLE_OUTPUT" "$MSG" ); then
   die "$LINENO: Did not identify failing output."
fi
if ! ( grep -qiF "writ" "$MSG" ); then
   die "$LINENO: Did not identify failing operation."
fi

# Try again with different argument order.
if ( "./$SPLITTER" "$INPUT" "$WRITABLE_OUTPUT" "$UNWRITABLE_OUTPUT" > "$MSG" ); then
   die "$LINENO: Unexpected success."
fi
if ! ( grep -qF "$UNWRITABLE_OUTPUT" "$MSG" ); then
   die "$LINENO: Did not identify failing output."
fi
if ! ( grep -qiF "writ" "$MSG" ); then
   die "$LINENO: Did not identify failing operation."
fi

# Success, cleanup and exit quietly.
rm -f "$MSG" "$WRITABLE_OUTPUT"
rmdir "$UNWRITABLE_OUTPUT"
exit 0