Merge pull request #300 from Gottox/fix/unpack-empty-files

file_ext: make sure file is always initialized when running a multithreaded iterator.

libsqsh/src/posix/file_ext.c

@@ -167,12 +167,12 @@ file_iterator_mt(
 	atomic_init(&mt->remaining_blocks, (size_t)block_count);
 	atomic_init(&mt->rv, 0);
 
-	if (block_count == 0) {
+	rv = sqsh__file_init(&mt->file, file->archive, inode_ref);
+	if (rv < 0) {
 		goto out;
 	}
 
-	rv = sqsh__file_init(&mt->file, file->archive, inode_ref);
-	if (rv < 0) {
+	if (block_count == 0) {
 		goto out;
 	}
 

test/tools/meson.build

@@ -4,6 +4,7 @@ sqsh_extended_test = [
     'cat/large-file-uncompressed.sh',
     'read-chunk/tail.sh',
     'unpack/repack.sh',
+    'unpack/empty_file.sh',
     'unpack/pathtraversal/pathtraversal.sh',
     'ls/large-tree.sh',
     'ls/large-tree-lookup.sh',

test/tools/unpack/empty_file.sh

@@ -0,0 +1,30 @@
+#!/bin/sh -ex
+
+######################################################################
+# @author       Enno Boland ([email protected])
+# @file         repack.sh
+# @created      Friday Mar 17, 2023 15:11:09 CET
+#
+# @description  This script creates a squashfs image, mounts it, and
+#               repacks it from the mounted path.
+######################################################################
+
+: "${BUILD_DIR:?BUILD_DIR is not set}"
+: "${MKSQUASHFS:?MKSQUASHFS is not set}"
+: "${SQSH_UNPACK:?SQSH_UNPACK is not set}"
+
+MKSQUASHFS_OPTS="-no-xattrs -noappend -all-root -mkfs-time 0"
+
+WORK_DIR="$BUILD_DIR/unpack-empty_file"
+
+mkdir -p "$WORK_DIR"
+cd "$WORK_DIR"
+
+mkdir -p root unpack
+
+touch root/empty_file
+
+# shellcheck disable=SC2086
+$MKSQUASHFS "root" "empty_file.squashfs" $MKSQUASHFS_OPTS
+
+$SQSH_UNPACK -Ve "$PWD/empty_file.squashfs" / "$PWD/unpack"