debian/tests/control

@@ -2,7 +2,7 @@
 # EDIT debian/tests/control.in INSTEAD!
 #
 Tests: pytest-with-recommends
-Depends: diffoscope, python3-pytest, file, linux-image-amd64 [amd64], abootimg, acl, binutils-multiarch, bzip2, caca-utils, colord, db-util, default-jdk-headless | default-jdk | java-sdk, device-tree-compiler, docx2txt, e2fsprogs, enjarify, fontforge-extras, fp-utils [!ppc64el !s390x], genisoimage, gettext, ghc, ghostscript, giflib-tools, gnumeric, gnupg, imagemagick, jsbeautifier, libarchive-tools, llvm, lz4 | liblz4-tool, mono-utils, odt2txt, openssh-client, pgpdump, poppler-utils, procyon-decompiler, r-base-core, rpm2cpio, sng, sqlite3, squashfs-tools, tcpdump, unzip, xmlbeans, xxd | vim-common, xz-utils, python3-distro, python3-argcomplete, python3-progressbar, python3-binwalk, python3-defusedxml, python3-guestfs, python3-jsondiff, python3-debian, python3-pyxattr, python3-rpm, python3-tlsh
+Depends: diffoscope, python3-pytest, file, linux-image-amd64 [amd64] | linux-image-generic [amd64], abootimg, acl, binutils-multiarch, bzip2, caca-utils, colord, db-util, default-jdk-headless | default-jdk | java-sdk, device-tree-compiler, docx2txt, e2fsprogs, enjarify, fontforge-extras, fp-utils [!ppc64el !s390x], genisoimage, gettext, ghc, ghostscript, giflib-tools, gnumeric, gnupg, imagemagick, jsbeautifier, libarchive-tools, llvm, lz4 | liblz4-tool, mono-utils, odt2txt, openssh-client, pgpdump, poppler-utils, procyon-decompiler, r-base-core, rpm2cpio, sng, sqlite3, squashfs-tools, tcpdump, unzip, xmlbeans, xxd | vim-common, xz-utils, python3-distro, python3-argcomplete, python3-progressbar, python3-binwalk, python3-defusedxml, python3-guestfs, python3-jsondiff, python3-debian, python3-pyxattr, python3-rpm, python3-tlsh
 
 Tests: pytest
 Depends: diffoscope, python3-pytest, file

diffoscope/comparators/fsimage.py

@@ -77,10 +77,23 @@ class FsImageContainer(Archive):
 
 
 class FsImageFile(File):
-    DESCRIPTION = "ext2/ext3/ext4/btrfs filesystems"
+    DESCRIPTION = "ext2/ext3/ext4/btrfs/fat filesystems"
     CONTAINER_CLASS = FsImageContainer
     FILE_TYPE_RE = re.compile(r'^(Linux.*filesystem data|BTRFS Filesystem).*')
 
+    @classmethod
+    def recognizes(cls, file):
+        # Avoid DOS / MBR file type as it generate a lot of false possitives,
+        # manually check "System identifier string" instead
+        with open(file.path, 'rb') as f:
+            f.seek(54)
+            if f.read(8) in (b'FAT12   ', b'FAT16   '):
+                return True
+            f.seek(82)
+            if f.read(8) == b'FAT32   ':
+                return True
+        return super().recognizes(file)
+
     def compare_details(self, other, source=None):
         differences = []
         my_fs = ''

tests/comparators/test_fsimage.py

@@ -30,6 +30,10 @@ from ..utils.tools import skip_unless_tools_exist, skip_unless_module_exists
 
 img1 = load_fixture('test1.ext4')
 img2 = load_fixture('test2.ext4')
+img1_fat12 = load_fixture('test1.fat12')
+img2_fat12 = load_fixture('test2.fat12')
+img1_fat16 = load_fixture('test1.fat16')
+img1_fat32 = load_fixture('test1.fat32')
 
 
 @pytest.fixture(scope="session")
@@ -55,6 +59,15 @@ def guestfs_tempdir():
 def test_identification(img1):
     assert isinstance(img1, FsImageFile)
 
+def test_identification_fat12(img1_fat12):
+    assert isinstance(img1_fat12, FsImageFile)
+
+def test_identification_fat16(img1_fat16):
+    assert isinstance(img1_fat16, FsImageFile)
+
+def test_identification_fat32(img1_fat32):
+    assert isinstance(img1_fat32, FsImageFile)
+
 
 @skip_unless_tools_exist('qemu-img')
 @skip_unless_module_exists('guestfs')
@@ -94,3 +107,27 @@ def test_compare_non_existing(monkeypatch, img1, guestfs_tempdir):
     difference = img1.compare(MissingFile('/nonexisting', img1))
     assert difference.source2 == '/nonexisting'
     assert difference.details[-1].source2 == '/dev/null'
+
+@pytest.fixture
+def differences_fat(img1_fat12, img2_fat12, guestfs_tempdir):
+    return img1_fat12.compare(img2_fat12).details
+
+
+@skip_unless_tools_exist('qemu-img')
+@skip_unless_module_exists('guestfs')
+def test_differences_fat(differences_fat, guestfs_tempdir):
+    assert differences_fat[0].source1 == 'filetype from file(1)'
+    assert differences_fat[1].source1 == 'test1.fat12.tar'
+    tarinfo = differences_fat[1].details[0]
+    tardiff = differences_fat[1].details[1]
+    assert tarinfo.source1 == 'file list'
+    assert tarinfo.source2 == 'file list'
+    assert tardiff.source1 == './test1.txt'
+    assert tardiff.source2 == './test1.txt'
+    expected_diff = get_data('fat12_expected_diffs')
+    found_diff = differences_fat[0].unified_diff + \
+        tarinfo.unified_diff + \
+        tardiff.unified_diff
+    # workaround for file(1) bug in stretch
+    found_diff = found_diff.replace('32 MB) ,', '32 MB),')
+    assert expected_diff == found_diff

tests/data/fat12_expected_diffs

+@@ -1 +1 @@
+-DOS/MBR boot sector, code offset 0x3c+2, OEM-ID "mkfs.fat", sectors/cluster 4, root entries 512, sectors 128 (volumes <=32 MB), Media descriptor 0xf8, sectors/FAT 1, sectors/track 32, heads 64, serial number 0xc345b241, unlabeled, FAT (12 bit)
++DOS/MBR boot sector, code offset 0x3c+2, OEM-ID "mkfs.fat", sectors/cluster 4, root entries 512, sectors 128 (volumes <=32 MB), Media descriptor 0xf8, sectors/FAT 1, sectors/track 32, heads 64, serial number 0xe8941362, unlabeled, FAT (12 bit)
+@@ -1,2 +1,2 @@
+ drwxr-xr-x   0        0        0        0 1970-01-01 00:00:00.000000 ./
+--rwxr-xr-x   0        0        0        6 2018-10-12 12:50:52.000000 ./test1.txt
++-rwxr-xr-x   0        0        0        6 2018-10-12 12:09:26.000000 ./test1.txt
+@@ -1 +1 @@
+-test1
++test2